changes

21 files changed, 3435 insertions, 846 deletions

diff --git a/Cargo.lock b/Cargo.lock
index a3a118e..6414157 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -415,6 +415,7 @@ dependencies = [
  "memchr",
  "nix",
  "radix_trie",
+ "rustyline-derive",
  "unicode-segmentation",
  "unicode-width",
  "utf8parse",
@@ -422,6 +423,17 @@ dependencies = [
 ]
 
 [[package]]
+name = "rustyline-derive"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e5af959c8bf6af1aff6d2b463a57f71aae53d1332da58419e30ad8dc7011d951"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.48",
+]
+
+[[package]]
 name = "smallvec"
 version = "1.13.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
diff --git a/matrix-bin/Cargo.toml b/matrix-bin/Cargo.toml
index c4b4d5a..bdb8fb8 100644
--- a/matrix-bin/Cargo.toml
+++ b/matrix-bin/Cargo.toml
@@ -12,4 +12,4 @@ clap = { version = "4", features = [ "derive" ] }
 ctrlc = "3"
 matrix = { path = "../matrix" }
 matrix-stdlib = { path = "../matrix-stdlib" }
-rustyline = "13"
+rustyline = { version = "13", features = [ "derive" ] }
diff --git a/matrix-bin/src/helper.rs b/matrix-bin/src/helper.rs
new file mode 100644
index 0000000..c0ac5ec
--- /dev/null
+++ b/matrix-bin/src/helper.rs
@@ -0,0 +1,312 @@
+use std::{borrow::Cow, rc::Rc, cell::RefCell};
+
+use matrix::{lex::{Lexer, TokenData, Token}, vm::Vm};
+use rustyline::{validate::{Validator, ValidationResult, ValidationContext}, highlight::Highlighter, Helper, Hinter, completion::Completer};
+
+#[derive(Helper, Hinter)]
+pub struct MatrixHelper {
+     vm: Rc<RefCell<Vm>>
+}
+
+impl MatrixHelper {
+    pub fn new(vm: Rc<RefCell<Vm>>) -> Self {
+        Self { vm }
+    }
+}
+
+macro_rules! unmatched {
+    ($token:expr, $matched:expr) => {
+        Ok(::rustyline::validate::ValidationResult::Invalid(Some(format!("Token '{:?}' at {}:{} does not have a matching '{:?}'", $token.data, $token.pos.row, $token.pos.col, $matched))))
+    };
+}
+
+impl Validator for MatrixHelper {
+
+    fn validate(&self, ctx: &mut ValidationContext) -> rustyline::Result<ValidationResult> {
+        let mut lexer = Lexer::new(ctx.input());
+        let mut stack = Vec::new();
+
+        loop {
+            use TokenData as T;
+            let token = match lexer.next_token() {
+                Ok(t) if t.data == T::Eof => break,
+                Ok(t) => t,
+                Err(err) => return Ok(ValidationResult::Invalid(Some(format!("{err}"))))
+            };
+
+            match token.data {
+                T::LeftParen |
+                    T::LeftBrack |
+                    T::LeftBrace |
+                    T::For |
+                    T::Try => { stack.push(token.data); },
+                T::RightParen =>
+                    match stack.pop() {
+                        Some(T::LeftParen) => {},
+                        _ => return unmatched!(token, T::LeftParen)
+                    },
+                T::RightBrack =>
+                    match stack.pop() {
+                        Some(T::LeftBrack) => {},
+                        _ => return unmatched!(token, T::LeftBrack)
+                    },
+                T::RightBrace =>
+                    match stack.pop() {
+                        Some(T::LeftBrace) => {},
+                        _ => return unmatched!(token, T::LeftBrace)
+                    },
+                T::In =>
+                    match stack.pop() {
+                        Some(T::For) => {},
+                        _ => return unmatched!(token, T::For)
+                    },
+                T::Catch =>
+                    match stack.pop() {
+                        Some(T::Try) => {},
+                        _ => return unmatched!(token, T::Try)
+                    },
+                _ => {}
+            };
+        }
+
+        if stack.is_empty() {
+            return Ok(ValidationResult::Valid(None))
+        } else {
+            return Ok(ValidationResult::Incomplete)
+        }
+    }
+
+    fn validate_while_typing(&self) -> bool {
+        true
+    }
+}
+
+fn find_matching_bracket(line: &str, pos: usize) -> Option<usize> {
+    if pos >= line.len() {
+        return None
+    }
+    let c = line.as_bytes()[pos];
+    let (target, fwd) = match c {
+        b'(' => (b')', true),
+        b')' => (b'(', false),
+        b'[' => (b']', true),
+        b']' => (b'[', false),
+        b'{' => (b'}', true),
+        b'}' => (b'{', false),
+        _ => return None,
+    };
+    let mut depth = 0;
+    let mut idx = 0;
+    if fwd {
+        let bytes = &line.as_bytes()[pos+1..];
+        for &b in bytes {
+            if b == c {
+                depth += 1;
+            } else if b == target {
+                if depth == 0 {
+                    return Some(pos + idx + 1)
+                } else {
+                    depth -= 1;
+                }
+            }
+            idx += 1;
+        }
+    } else {
+        let bytes = &line.as_bytes()[..pos];
+        for &b in bytes.iter().rev() {
+            if b == c {
+                depth += 1;
+            } else if b == target {
+                if depth == 0 {
+                    return Some(pos - idx - 1)
+                } else {
+                    depth -= 1;
+                }
+            }
+            idx += 1;
+        }
+    }
+    None
+}
+
+fn get_token_at(line: &str, pos: usize) -> Option<Token> {
+    use TokenData as T;
+    let mut lexer = Lexer::new(line);
+    loop {
+        match lexer.next_token() {
+            Ok(Token { data: T::Eof, ..}) => return None,
+            Ok(t) if t.bidx <= pos && (t.bidx + t.blen) > pos => return Some(t),
+            Err(_) => return None,
+            _ => continue
+        }
+    }
+}
+
+fn find_matching_ident(line: &str, pos: usize) -> Option<Rc<str>> {
+    use TokenData as T;
+    match get_token_at(line, pos) {
+        Some(Token { data: T::Ident(ident), ..}) => Some(ident),
+        _ => return None
+    }
+}
+
+impl Highlighter for MatrixHelper {
+    fn highlight<'l>(&self, line: &'l str, pos: usize) -> Cow<'l, str> {
+
+        let matching = find_matching_bracket(line, pos);
+        let ident = find_matching_ident(line, pos);
+
+        use TokenData as T;
+        let mut lexer = Lexer::new(line);
+        let mut buf = String::new();
+        let mut last = 0;
+        loop {
+            let token = match lexer.next_token() {
+                Ok(t) if t.data == T::Eof => break,
+                Ok(t) => t,
+                Err(_) => break
+            };
+            let bl = token.bidx;
+            let br = token.bidx + token.blen;
+            buf += &line[last..bl];
+            last = br;
+
+            let color = match token.data {
+                T::LeftParen |
+                    T::RightParen |
+                    T::LeftBrack |
+                    T::RightBrack |
+                    T::LeftBrace |
+                    T::RightBrace
+                    => {
+                        match matching {
+                            Some(idx) if bl == idx || bl == pos => "\x1b[33;40m",
+                            _ => ""
+                        }
+                    }
+                T::Int(_) |
+                    T::True |
+                    T::False |
+                    T::Nil |
+                    T::Float(_) |
+                    T::Complex(_)
+                    => "\x1b[33m",
+                T::Ident(tok) => {
+                    match (ident.as_ref(), lexer.peek_token()) {
+                        (Some(ident), Ok(t)) if t.data == T::LeftParen && ident.as_ref() == tok.as_ref() => "\x1b[34;40m",
+                        (Some(ident), _) if ident.as_ref() == tok.as_ref() => "\x1b[40m",
+                        (_, Ok(t)) if t.data == T::LeftParen => "\x1b[34m",
+                        _ => ""
+                    }
+                }
+                T::Regex(_) => "\x1b[31m",
+                T::String(_) => "\x1b[32m",
+                T::If |
+                    T::Else |
+                    T::While |
+                    T::Let |
+                    T::Function |
+                    T::Continue |
+                    T::Break |
+                    T::Do |
+                    T::Loop |
+                    T::Return |
+                    T::For |
+                    T::In |
+                    T::Try |
+                    T::Catch
+                    => "\x1b[38;2;203;166;247m",
+                _ => {
+                    buf += &token.str;
+                    continue;
+                }
+            };
+
+            let clear = "\x1b[0m";
+
+            buf += &format!("{color}{}{clear}", token.str);
+        }
+
+        buf += &line[last..];
+
+        Cow::Owned(buf)
+    }
+
+    fn highlight_prompt<'b, 's: 'b, 'p: 'b>(
+        &'s self,
+        prompt: &'p str,
+        default: bool,
+    ) -> std::borrow::Cow<'b, str> {
+        let _ = default;
+        Cow::Owned(format!("\x1b[35m{prompt}\x1b[0m"))
+    }
+
+    fn highlight_hint<'h>(&self, hint: &'h str) -> Cow<'h, str> {
+        Cow::Owned(format!("    \x1b[31;40m Error: \x1b[0;40m{hint} \x1b[0m"))
+    }
+
+    fn highlight_candidate<'c>(
+        &self,
+        candidate: &'c str,
+        completion: rustyline::CompletionType,
+    ) -> std::borrow::Cow<'c, str> {
+        let _ = completion;
+        Cow::Borrowed(candidate)
+    }
+
+    fn highlight_char(&self, line: &str, _pos: usize, forced: bool) -> bool {
+        forced || !line.is_empty()
+    }
+}
+
+impl Completer for MatrixHelper {
+    type Candidate = Rc<str>;
+
+    fn complete(
+        &self,
+        line: &str,
+        pos: usize,
+        ctx: &rustyline::Context<'_>,
+    ) -> rustyline::Result<(usize, Vec<Self::Candidate>)> {
+
+        let mut idx = 0;
+        let mut buf = String::new();
+        let mut start = 0;
+
+        for char in line.chars() {
+            if buf.is_empty() && char.is_alphabetic() {
+                start = idx;
+                buf.push(char);
+            } else if !buf.is_empty() && char.is_alphanumeric() {
+                buf.push(char);
+            } else {
+                if idx >= pos {
+                    break;
+                } else {
+                    buf.clear();
+                }
+            }
+            idx += char.len_utf8();
+        }
+
+        let _ = (line, pos, ctx);
+        let globals = self.vm.borrow().global_names();
+        let names: Vec<Rc<str>> = globals
+            .borrow()
+            .clone()
+            .into_iter()
+            .filter(|n| n.starts_with(&buf))
+            .collect();
+
+        if buf.is_empty() {
+            start = pos;
+        }
+
+        Ok((start, names))
+    }
+
+    fn update(&self, line: &mut rustyline::line_buffer::LineBuffer, start: usize, elected: &str, cl: &mut rustyline::Changeset) {
+        let end = line.pos();
+        line.replace(start..end, elected, cl);
+    }
+}
diff --git a/matrix-bin/src/main.rs b/matrix-bin/src/main.rs
index 909ee77..225b353 100644
--- a/matrix-bin/src/main.rs
+++ b/matrix-bin/src/main.rs
@@ -1,9 +1,10 @@
-use std::{path::PathBuf, io::{self, Read, IsTerminal}, fs};
-use clap::Parser as ArgParser;
+use std::{path::PathBuf, io::{self, Read, IsTerminal}, fs, cell::RefCell, rc::Rc};
+use clap::{Parser as ArgParser, ColorChoice};
 use matrix::{compiler::{Compiler, CompilerBuilder}, vm::Vm, parse::{Parser, ParserBuilder}, value::Value};
 use repl::Repl;
 
 mod repl;
+mod helper;
 
 #[derive(Debug, ArgParser)]
 #[command(version, long_about = None)]
@@ -19,6 +20,10 @@ pub struct Args {
     #[arg(short, long)]
     debug: bool,
 
+    /// Choses color
+    #[arg(short, long)]
+    color: Option<ColorChoice>,
+
     /// Disables optimizations
     #[arg(long)]
     disable_optimizations: bool,
@@ -27,8 +32,11 @@ pub struct Args {
 pub struct State<'a> {
     parser: Parser,
     compiler: Compiler<'a>,
-    vm: Vm,
-    repl: bool
+    vm: Rc<RefCell<Vm>>,
+    repl: bool,
+    color: bool,
+    #[allow(unused)]
+    debug: bool,
 }
 
 impl<'a> State<'a> {
@@ -60,20 +68,32 @@ impl<'a> State<'a> {
 
         matrix_stdlib::load(&mut vm);
 
-        (Self { parser, vm, compiler, repl }, file)
+        let color = match args.color {
+            Some(ColorChoice::Auto) | None => {
+                io::stdout().is_terminal()
+            },
+            Some(ColorChoice::Always) => true,
+            Some(ColorChoice::Never) => false,
+        };
+
+        (Self { parser, vm: Rc::new(RefCell::new(vm)), compiler, repl, debug: args.debug, color }, file)
     }
 
     pub fn execute(&mut self, code: String) -> matrix::Result<Value> {
         let ast = self.parser.parse(code)?;
         let fun = self.compiler.compile(&ast)?;
-        let val = self.vm.run(fun)?;
+        let val = self.vm.try_borrow_mut().unwrap().run(fun)?;
         Ok(val)
     }
 
 }
 
-pub fn error(err: matrix::Error) {
-    println!("\x1b[31m\x1b[1mError:\x1b[0m {err}");
+pub fn error(err: matrix::Error, state: &State) {
+    if state.color {
+        println!("\x1b[31m\x1b[1mError:\x1b[0m {err}");
+    } else {
+        println!("Error: {err}");
+    }
 }
 
 fn read_stdin() -> String {
@@ -93,7 +113,7 @@ fn main() {
 
     if let Some(file) = file {
         if let Err(err) = state.execute(file) {
-            error(err);
+            error(err, &state);
         }
     }
 
diff --git a/matrix-bin/src/repl.rs b/matrix-bin/src/repl.rs
index 1b5addc..f2964d4 100644
--- a/matrix-bin/src/repl.rs
+++ b/matrix-bin/src/repl.rs
@@ -1,9 +1,9 @@
 use std::{io::Write, sync::atomic::Ordering};
 
 use matrix::{value::Value, vm::Interupt};
-use rustyline::Config;
+use rustyline::{Config, EditMode, ColorMode, Editor, CompletionType};
 
-use crate::State;
+use crate::{State, helper::MatrixHelper};
 
 pub struct Repl<'a> {
     state: State<'a>
@@ -17,24 +17,39 @@ impl<'a> Repl<'a> {
 
     pub fn run(&mut self)  {
 
-        let interupt = self.state.vm.interupt();
+        let interupt = self.state.vm.borrow().interupt();
         ctrlc::set_handler(move || {
             interupt.store(Interupt::KeyboardInterupt as usize, Ordering::SeqCst);
         }).unwrap();
 
         let config = Config::builder()
             .check_cursor_position(true)
+            .completion_type(CompletionType::List)
+            .edit_mode(EditMode::Emacs)
+            .color_mode(if self.state.color { ColorMode::Enabled } else { ColorMode::Disabled })
             .build();
-        let mut rl = rustyline::DefaultEditor::with_config(config).unwrap();
+
+        let helper = MatrixHelper::new(self.state.vm.clone());
+
+        let mut rl = Editor::with_config(config).unwrap();
+        rl.set_helper(Some(helper));
+
         loop {
             let Ok(line) = rl.readline(">> ") else {
                 break;
             };
+            if let Err(_) = rl.add_history_entry(&line) {
+                break;
+            };
             match self.state.execute(line) {
-                Err(err) => crate::error(err),
+                Err(err) => crate::error(err, &self.state),
                 Ok(val) => {
                     if val != Value::Nil {
-                        println!("{val}");
+                        if self.state.color {
+                            println!("{val:#}");
+                        } else {
+                            println!("{val}");
+                        }
                     }
                 }
             }
diff --git a/matrix-macros/src/lib.rs b/matrix-macros/src/lib.rs
index 8099fd6..b12d30b 100644
--- a/matrix-macros/src/lib.rs
+++ b/matrix-macros/src/lib.rs
@@ -1,16 +1,15 @@
 use proc_macro::TokenStream;
-use syn::{ItemFn, parse::Parse, Token, LitBool, LitInt};
+use syn::{ItemFn, parse::Parse, Token, LitInt};
 use quote::quote;
 
 struct NativeFuncParams {
     arity: LitInt,
-    variadic: LitBool,
+    variadic: Option<Token![..]>,
 }
 
 impl Parse for NativeFuncParams {
     fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
         let arity = input.parse()?;
-        input.parse::<Token![,]>()?;
         let variadic = input.parse()?;
         Ok(Self { arity , variadic })
     }
@@ -22,7 +21,7 @@ pub fn native_func(input: TokenStream, annotated_item: TokenStream) -> TokenStre
 
     let input: NativeFuncParams = syn::parse(input).unwrap();
     let arity = input.arity;
-    let variadic = input.variadic;
+    let variadic = input.variadic.is_some();
 
     let visibility = itemfn.vis;
     let block = itemfn.block;
@@ -43,7 +42,11 @@ pub fn native_func(input: TokenStream, annotated_item: TokenStream) -> TokenStre
                 name: ::std::rc::Rc::from( #name_str ),
                 arity: #arity,
                 variadic: #variadic,
-                fun: ::matrix::chunk::InnerFunction::Native(Box::new(|#inputs| #output #block))
+                fun: ::matrix::chunk::InnerFunction::Native(
+                    ::std::rc::Rc::new(
+                        |#inputs| #output #block
+                    )
+                )
             })
         }
     };
diff --git a/matrix-stdlib/src/core.rs b/matrix-stdlib/src/core.rs
new file mode 100644
index 0000000..183c142
--- /dev/null
+++ b/matrix-stdlib/src/core.rs
@@ -0,0 +1,181 @@
+use std::hash::{DefaultHasher, Hash, Hasher};
+
+use matrix::{vm::Vm, value::Value, unpack_args, Result, unpack_varargs};
+use matrix_macros::native_func;
+use crate::{VmArgs, error};
+
+
+fn to_radix(r: i64, mut n: i64) -> String {
+    let mut result = String::new();
+    let mut idx = 0;
+    if n == 0 {
+        result.push('0');
+        return result
+    } else if n < 0 {
+        n = -n;
+        idx = 1;
+        result.push('-');
+    }
+    while n != 0 {
+        let c = std::char::from_digit((n % r) as u32, r as u32).unwrap();
+        result.insert(idx, c);
+        n /= r;
+    }
+    result
+}
+
+#[native_func(1)]
+fn bin(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [value] = unpack_args!(args);
+    match value {
+        Value::Int(n) => Ok(Value::String(to_radix(2, n).into())),
+        _ => error!("bin requires a integer agument")
+    }
+}
+
+#[native_func(1)]
+fn sex(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [value] = unpack_args!(args);
+    match value {
+        Value::Int(n) => Ok(Value::String(to_radix(6, n).into())),
+        _ => error!("sex requires a integer agument")
+    }
+}
+
+#[native_func(1)]
+fn oct(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [value] = unpack_args!(args);
+    match value {
+        Value::Int(n) => Ok(Value::String(to_radix(8, n).into())),
+        _ => error!("oct requires a integer agument")
+    }
+}
+
+#[native_func(1)]
+fn hex(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [value] = unpack_args!(args);
+    match value {
+        Value::Int(n) => Ok(Value::String(to_radix(16, n).into())),
+        _ => error!("hex requires a integer agument")
+    }
+}
+
+#[native_func(2)]
+fn radix(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [radix, value] = unpack_args!(args);
+    match (radix, value) {
+        (Value::Int(r), Value::Int(n)) => Ok(Value::String(to_radix(r, n).into())),
+        _ => error!("radix requires two integer aguments")
+    }
+}
+
+#[native_func(1..)]
+fn append(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let ([list], args) = unpack_varargs!(args);
+    let Value::List(mut list) = list else {
+        return error!("append requires a list")
+    };
+    for arg in args {
+        list.push(arg);
+    };
+    Ok(Value::List(list))
+}
+
+#[native_func(2)]
+fn push(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [list, value] = unpack_args!(args);
+    let Value::List(mut list) = list else {
+        return error!("push requires a list")
+    };
+    list.push(value);
+    Ok(Value::List(list))
+}
+
+#[native_func(1)]
+fn pop(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [list] = unpack_args!(args);
+    let Value::List(mut list) = list else {
+        return error!("pop requires a list")
+    };
+    match list.pop() {
+        Some(v) => Ok(v),
+        None => Ok(Value::Nil)
+    }
+}
+
+#[native_func(2)]
+fn remove(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [list, index] = unpack_args!(args);
+    let Value::List(mut list) = list else {
+        return error!("remove requires a list")
+    };
+    let Value::Int(i) = index else {
+        return error!("remove reuqires a int index");
+    };
+    if i < 0 || i as usize >= list.len() {
+        Ok(Value::Nil)
+    } else {
+        Ok(list.remove(i as usize))
+    }
+}
+
+#[native_func(1)]
+fn hash(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [value] = unpack_args!(args);
+    if let Err(e) = value.can_hash() {
+        return Err(e)
+    };
+    let mut hasher = DefaultHasher::new();
+    value.hash(&mut hasher);
+    let fin = hasher.finish();
+    Ok(Value::Int(fin as u32 as i64))
+}
+
+#[native_func(1)]
+fn ord(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [value] = unpack_args!(args);
+    let Value::String(str) = value else {
+        return error!("ord requires a 1 length string")
+    };
+    if str.len() != 1 {
+        return error!("ord requires a 1 length string")
+    }
+    let char = str.chars().next().unwrap();
+    Ok(Value::Int(char as i64))
+}
+
+#[native_func(1)]
+fn chr(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [value] = unpack_args!(args);
+    let Value::Int(i) = value else {
+        return error!("chr requires an int")
+    };
+    match char::from_u32(i as u32) {
+        Some(c) => Ok(Value::String(String::from(c).into())),
+        None => error!("unable to get char from: {}", i as u32)
+    }
+}
+
+#[native_func(1)]
+fn str(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [value] = unpack_args!(args);
+    Ok(Value::String(format!("{value}").into()))
+}
+
+pub fn load(vm: &mut Vm) {
+    vm.load_global_fn(bin(), "bin");
+    vm.load_global_fn(sex(), "sex");
+    vm.load_global_fn(oct(), "oct");
+    vm.load_global_fn(hex(), "hex");
+    vm.load_global_fn(radix(), "radix");
+    vm.load_global_fn(str(), "str");
+
+    vm.load_global_fn(append(), "append");
+    vm.load_global_fn(push(), "push");
+    vm.load_global_fn(pop(), "pop");
+    vm.load_global_fn(remove(), "remove");
+
+    vm.load_global_fn(hash(), "hash");
+    vm.load_global_fn(ord(), "ord");
+    vm.load_global_fn(chr(), "chr");
+}
diff --git a/matrix-stdlib/src/io.rs b/matrix-stdlib/src/io.rs
index 288e99e..d72248c 100644
--- a/matrix-stdlib/src/io.rs
+++ b/matrix-stdlib/src/io.rs
@@ -1,36 +1,175 @@
-use matrix::{value::Value, self, vm::Vm, Result};
+use std::{io::{self, Read, Write}, cell::RefCell, fs::OpenOptions, rc::Rc};
+
+use matrix::{value::Value, self, vm::Vm, Result, unpack_varargs, iter, unpack_args};
 use matrix_macros::native_func;
+use crate::{error, VmArgs};
 
-#[native_func(1, true)]
-fn print(_vm: &mut Vm, args: Vec<Value>) -> Result<Value> {
-    let [values] = args.try_into().unwrap();
-    if let Value::List(list) = values {
-        for (i, value) in list.iter().enumerate() {
-            print!("{}", value.boring_print());
-            if i != 0 {
-                print!(" ");
-            }
+#[native_func(0..)]
+fn print(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let ([], varags) = unpack_varargs!(args);
+    for (i, value) in varags.into_iter().enumerate() {
+        if i != 0 {
+            print!(" ");
         }
+        print!("{value}");
     }
     Ok(Value::Nil)
 }
 
-#[native_func(1, true)]
-fn println(_vm: &mut Vm, args: Vec<Value>) -> Result<Value> {
-    let [values] = args.try_into().unwrap();
-    if let Value::List(list) = values {
-        for (i, value) in list.iter().enumerate() {
-            print!("{}", value.boring_print());
-            if i != 0 {
-                print!(" ");
-            }
+#[native_func(0..)]
+fn println(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let ([], varags) = unpack_varargs!(args);
+    for (i, value) in varags.into_iter().enumerate() {
+        if i != 0 {
+            print!(" ");
         }
+        print!("{value}");
     }
     print!("\n");
     Ok(Value::Nil)
 }
 
+#[native_func(0)]
+fn readln(_: VmArgs, _: Vec<Value>) -> Result<Value> {
+    let mut input = String::new();
+    match io::stdin().read_line(&mut input) {
+        Ok(_) => {
+            match input.pop() {
+                Some(c) if c == '\n' => {},
+                Some(c) => input.push(c),
+                None => {}
+            };
+            Ok(Value::String(input.into()))
+        },
+        Err(err) => error!("cant read from stdin: {err}")
+    }
+}
+
+#[native_func(1)]
+fn input(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [prompt] = unpack_args!(args);
+    let mut input = String::new();
+    print!("{prompt}");
+    let _ = io::stdout().flush();
+    match io::stdin().read_line(&mut input) {
+        Ok(_) => {
+            match input.pop() {
+                Some(c) if c == '\n' => {},
+                Some(c) => input.push(c),
+                None => {}
+            };
+            Ok(Value::String(input.into()))
+        },
+        Err(err) => error!("cant read from stdin: {err}")
+    }
+}
+
+#[native_func(0)]
+fn readlines(_: VmArgs, _: Vec<Value>) -> Result<Value> {
+    let lines = RefCell::new(io::stdin().lines());
+    Ok(iter!(move |_,_| {
+        match lines.borrow_mut().next() {
+            Some(Ok(line)) => Ok(Value::String(line.into())),
+            _ => Ok(Value::Nil)
+        }
+    }))
+}
+
+#[native_func(2)]
+fn file_open(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [path, mode] = unpack_args!(args);
+    let Value::String(mode) = mode else {
+        return error!("open mode must be a string")
+    };
+    let Value::String(path) = path else {
+        return error!("open path must be a string")
+    };
+    let file = match mode.as_ref() {
+        "r" => OpenOptions::new().read(true).open(path.as_ref()),
+        "w" => OpenOptions::new().write(true).create(true).truncate(true).open(path.as_ref()),
+        "a" => OpenOptions::new().write(true).create(true).append(true).open(path.as_ref()),
+        "r+" => OpenOptions::new().read(true).write(true).open(path.as_ref()),
+        "w+" => OpenOptions::new().read(true).write(true).create(true).truncate(true).open(path.as_ref()),
+        "a+" => OpenOptions::new().read(true).write(true).create(true).append(true).open(path.as_ref()),
+        _ => return error!("invalid open mode: {mode}")
+    };
+
+    match file {
+        Ok(file) => Ok(Value::File(Rc::new(RefCell::new(file)))),
+        Err(err) => return error!("cannot open '{path}': {err}")
+    }
+}
+
+#[native_func(1)]
+fn file_read(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [file] = unpack_args!(args);
+    let Value::File(file) = file else {
+        return error!("file read requires a file")
+    };
+    let mut contents = String::new();
+    if let Err(err) = file.try_borrow_mut().unwrap().read_to_string(&mut contents) {
+        return error!("cannot read file: '{err}'")
+    };
+    Ok(Value::String(contents.into()))
+}
+
+#[native_func(1)]
+fn file_lines(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [file] = unpack_args!(args);
+    let Value::File(file) = file else {
+        return error!("file read requires a file")
+    };
+    let mut contents = String::new();
+    if let Err(err) = file.try_borrow_mut().unwrap().read_to_string(&mut contents) {
+        return error!("cannot read file: '{err}'")
+    };
+    let lines: Vec<Rc<str>> = contents.split_inclusive("\n").map(|s| Rc::from(s)).collect();
+    let lines = RefCell::new(lines.into_iter());
+    Ok(iter!(move |_,_| {
+        match lines.borrow_mut().next() {
+            Some(line) => Ok(Value::String(line)),
+            None => Ok(Value::Nil)
+        }
+    }))
+}
+
+#[native_func(2)]
+fn file_write(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [file, content] = unpack_args!(args);
+    let Value::File(file) = file else {
+        return error!("file write requires a file")
+    };
+    let content = format!("{content}");
+    if let Err(err) = file.try_borrow_mut().unwrap().write_all(content.as_bytes()) {
+        return error!("cannot write file: '{err}'")
+    };
+    Ok(Value::Nil)
+}
+
+#[native_func(0..)]
+fn throw(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let ([], varargs) = unpack_varargs!(args);
+
+    let mut str = String::new();
+    for (i, v) in varargs.into_iter().enumerate() {
+        if i != 0 {
+            str.push_str(" ");
+        }
+         str.push_str(&format!("{v}"));
+    }
+
+    error!("{str}")
+}
+
 pub fn load(vm: &mut Vm) {
-    vm.load_native_fn(print());
-    vm.load_native_fn(println());
+    vm.load_global_fn(print(), "print");
+    vm.load_global_fn(println(), "println");
+    vm.load_global_fn(readln(), "readln");
+    vm.load_global_fn(input(), "input");
+    vm.load_global_fn(readlines(), "readlines");
+    vm.load_global_fn(file_open(), "file_open");
+    vm.load_global_fn(file_read(), "file_read");
+    vm.load_global_fn(file_lines(), "file_lines");
+    vm.load_global_fn(file_write(), "file_write");
+    vm.load_global_fn(throw(), "throw");
 }
diff --git a/matrix-stdlib/src/iter.rs b/matrix-stdlib/src/iter.rs
new file mode 100644
index 0000000..74056ce
--- /dev/null
+++ b/matrix-stdlib/src/iter.rs
@@ -0,0 +1,544 @@
+use std::{cell::RefCell, rc::Rc};
+use matrix::{iter, vm::Vm, value::Value, Result, unpack_varargs, unpack_args};
+use matrix_macros::native_func;
+use crate::{error, VmArgs};
+
+use Value as V;
+
+macro_rules! next {
+    ($vm:expr, $frame:expr, $iter:expr) => {
+        $vm.run_fn($frame, $iter.clone(), vec![])
+    };
+}
+
+#[native_func(1)]
+fn len(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [value] = unpack_args!(args);
+    let len = match value {
+        V::List(l) => l.len(),
+        V::Matrix(m) => m.values.len(),
+        V::String(s) => s.len(),
+        V::Table(t) => t.len(),
+        _ => 1
+    };
+    Ok(V::Int(len as i64))
+}
+
+#[native_func(1)]
+fn sum((vm, frame): VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [iter] = unpack_args!(args);
+    let iter = iter.into_iter_fn()?;
+    let mut res = next!(vm, frame, iter)?;
+    if res == Value::Nil {
+        return Ok(res)
+    };
+    loop {
+        let next = next!(vm, frame, iter)?;
+        if next == Value::Nil { break }
+        res = (res + next)?;
+    }
+    Ok(res)
+}
+
+#[native_func(0..)]
+fn range(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let ([], varargs) = unpack_varargs!(args);
+    let (min, max, step) = match varargs.as_slice() {
+        [V::Int(max)] => {
+            (0, *max, 1)
+        },
+        [V::Int(min), V::Int(max)] => {
+            (*min, *max, 1)
+        },
+        [V::Int(min), V::Int(max), V::Int(step)] => {
+            (*min, *max, *step)
+        },
+        _ => return error!("range takes 1 to 3 [Int]'s")
+    };
+
+    let i = RefCell::new(min);
+    Ok(iter!(move |_,_| {
+        let curr = *(i.borrow());
+        *(i.borrow_mut()) = curr + step;
+        if curr >= max {
+            return Ok(V::Nil)
+        } else {
+            return Ok(V::Int(curr))
+        }
+    }))
+}
+
+#[native_func(1)]
+fn iter(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [value] = unpack_args!(args);
+    Ok(value.into_iter()?)
+}
+
+#[native_func(1)]
+fn once(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [value] = unpack_args!(args);
+    let first = RefCell::new(false);
+    Ok(iter!(move |_,_| {
+        if *first.borrow() == false {
+            *first.borrow_mut() = true;
+            Ok(value.clone())
+        } else {
+            Ok(Value::Nil)
+        }
+    }))
+}
+
+#[native_func(1)]
+fn list((vm, frame): VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [iter] = unpack_args!(args);
+    let iter = iter.into_iter_fn()?;
+    let mut list = Vec::new();
+    loop {
+        let res = next!(vm, frame, iter)?;
+        if res == Value::Nil { break }
+        list.push(res);
+    }
+    Ok(Value::List(list.into()))
+}
+
+#[native_func(2)]
+fn map(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [fun, iter] = unpack_args!(args);
+    let iter = iter.into_iter_fn()?;
+    let Value::Function(fun) = fun else {
+        return error!("map 1st arg must be a function")
+    };
+    Ok(iter!(move |(vm,frame),_| {
+        let input = next!(vm, frame, iter)?;
+        if input == Value::Nil {
+            return Ok(input)
+        }
+        vm.run_fn(frame, fun.clone(), vec![input])
+    }))
+}
+
+#[native_func(2)]
+fn fold((vm, frame): VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [fun, iter] = unpack_args!(args);
+    let iter = iter.into_iter_fn()?;
+    let Value::Function(fun) = fun else {
+        return error!("fold 1st arg must be a function")
+    };
+    let mut res = next!(vm, frame, iter)?;
+    if res == Value::Nil {
+        return Ok(Value::Nil)
+    };
+    loop {
+        let next = next!(vm, frame, iter)?;
+        if next == Value::Nil {
+            return Ok(res)
+        };
+        res = vm.run_fn(frame, fun.clone(), vec![res, next])?;
+    }
+}
+
+#[native_func(3)]
+fn foldi((vm, frame): VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [init, fun, iter] = unpack_args!(args);
+    let iter = iter.into_iter_fn()?;
+    let Value::Function(fun) = fun else {
+        return error!("foldi 1st arg must be a function")
+    };
+    let mut res = init;
+    loop {
+        let next = next!(vm, frame, iter)?;
+        if next == Value::Nil {
+            return Ok(res)
+        };
+        res = vm.run_fn(frame, fun.clone(), vec![res, next])?;
+    }
+}
+
+#[native_func(1)]
+fn count((vm, frame): VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [iter] = unpack_args!(args);
+    let iter = iter.into_iter_fn()?;
+    let mut len = 0;
+    loop {
+        let res = vm.run_fn(frame, iter.clone(), vec![])?;
+        if res == Value::Nil { break };
+        len += 1;
+    }
+    Ok(Value::Int(len))
+}
+
+#[native_func(3)]
+fn scan(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [init, fun, iter] = unpack_args!(args);
+    let iter = iter.into_iter_fn()?;
+    let Value::Function(fun) = fun else {
+        return error!("scan 2nd arg must be a function")
+    };
+    let res = RefCell::new(init);
+    Ok(iter!(move |(vm,frame),_| {
+        let next = next!(vm, frame, iter)?;
+        if next == Value::Nil {
+            return Ok(Value::Nil)
+        };
+        let res_next = vm.run_fn(frame, fun.clone(), vec![res.borrow().clone(), next])?;
+        *res.borrow_mut() = res_next;
+        Ok(res.borrow().clone())
+    }))
+}
+
+#[native_func(2)]
+fn filter(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [fun, iter] = unpack_args!(args);
+    let iter = iter.into_iter_fn()?;
+    let Value::Function(fun) = fun else {
+        return error!("filter 1st arg must be a function")
+    };
+    Ok(iter!(move |(vm,frame),_| {
+        loop {
+            let next = next!(vm, frame, iter)?;
+            if next == Value::Nil {
+                return Ok(Value::Nil)
+            }
+            let res = vm.run_fn(frame, fun.clone(), vec![next.clone()])?;
+            if !!res {
+                return Ok(next)
+            }
+        }
+    }))
+}
+
+#[native_func(0..)]
+fn chain(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let ([], iters) = unpack_varargs!(args);
+
+    let mut chaind = Vec::new();
+    for iter in iters {
+        chaind.push(iter.into_iter_fn()?);
+    }
+
+    chaind.reverse();
+    let chaind = RefCell::new(chaind);
+    Ok(iter!(move |(vm,frame), _| {
+        loop {
+            let curr = match chaind.borrow_mut().last() {
+                Some(iter) => iter.clone(),
+                None => return Ok(Value::Nil)
+            };
+            match vm.run_fn(frame, curr.clone(), vec![]) {
+                Ok(Value::Nil) => {
+                    chaind.borrow_mut().pop();
+                    continue;
+                },
+                v => return v
+            };
+        }
+    }))
+}
+
+#[native_func(1)]
+fn lines(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [str] = unpack_args!(args);
+    let Value::String(str) = str else {
+        return error!("lines arg must be a string")
+    };
+    let lines: Vec<Rc<str>> = str.split_inclusive("\n").map(|s| Rc::from(s)).collect();
+    let res = RefCell::new(lines.into_iter());
+    Ok(iter!(move |_,_| {
+        match res.borrow_mut().next() {
+            Some(line) => Ok(Value::String(line)),
+            None => Ok(Value::Nil)
+        }
+    }))
+}
+
+#[native_func(1)]
+fn skip((vm, frame): VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [count, iter] = unpack_args!(args);
+    let iter = iter.into_iter_fn()?;
+    let Value::Int(i) = count else {
+        return error!("skip count requires a int")
+    };
+    for _ in 0..i {
+        next!(vm, frame, iter)?;
+    }
+    Ok(Value::Iter(iter))
+}
+
+#[native_func(2)]
+fn alternate(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [il, ir] = unpack_args!(args);
+    let il = il.into_iter_fn()?;
+    let ir = ir.into_iter_fn()?;
+    let flag = RefCell::new(Some(0));
+    Ok(iter!(move |(vm, frame),_| {
+        let f = *flag.borrow();
+        match f {
+            Some(0) => {
+                let val = next!(vm, frame, il)?;
+                if val == Value::Nil {
+                    *flag.borrow_mut() = None;
+                } else {
+                    *flag.borrow_mut() = Some(1);
+                }
+                Ok(val)
+            },
+            Some(1) => {
+                let val = next!(vm, frame, ir)?;
+                if val == Value::Nil {
+                    *flag.borrow_mut() = None;
+                } else {
+                    *flag.borrow_mut() = Some(0);
+                }
+                Ok(val)
+            },
+            _ => Ok(Value::Nil)
+        }
+    }))
+}
+
+#[native_func(2)]
+fn intersperse(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [value, iter] = unpack_args!(args);
+    let iter = iter.into_iter_fn()?;
+    let flag = RefCell::new(Some(0));
+    Ok(iter!(move |(vm, frame),_| {
+        let f = *flag.borrow();
+        match f {
+            Some(0) => {
+                let val = next!(vm, frame, iter)?;
+                if val == Value::Nil {
+                    *flag.borrow_mut() = None;
+                } else {
+                    *flag.borrow_mut() = Some(1);
+                }
+                Ok(val)
+            },
+            Some(1) => {
+                let val = value.clone();
+                *flag.borrow_mut() = Some(0);
+                Ok(val)
+            },
+            _ => Ok(Value::Nil)
+        }
+    }))
+}
+
+#[native_func(2)]
+fn zip(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [il, ir] = unpack_args!(args);
+    let il = il.into_iter_fn()?;
+    let ir = ir.into_iter_fn()?;
+    let flag = RefCell::new(true);
+    Ok(iter!(move |(vm, frame),_| {
+        let f = *flag.borrow();
+        match f {
+            true => {
+                let vl = next!(vm, frame, il)?;
+                let vr = next!(vm, frame, ir)?;
+                if vl == Value::Nil || vr == Value::Nil {
+                    *flag.borrow_mut() = false;
+                }
+                Ok(Value::List(vec![vl, vr].into()))
+            },
+            _ => Ok(Value::Nil)
+        }
+    }))
+}
+
+#[native_func(1)]
+fn unzip((vm, frame): VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [iter] = unpack_args!(args);
+    let iter = iter.into_iter_fn()?;
+    let mut ll = Vec::new();
+    let mut lr = Vec::new();
+    loop {
+        let val = next!(vm, frame, iter)?;
+        if val == Value::Nil {
+            break;
+        }
+        let Value::List(vals) = val else {
+            return error!("unzip only works over a iterator of pairs");
+        };
+        let vals = vals.into_inner();
+        if vals.len() != 2 {
+            return error!("unzip only works over a iterator of pairs");
+        }
+        let [l, r] = vals.try_into().unwrap();
+        ll.push(l);
+        lr.push(r);
+    }
+    let ll = Value::List(ll.into());
+    let lr = Value::List(lr.into());
+    Ok(Value::List(vec![ll, lr].into()))
+}
+
+#[native_func(1)]
+fn cycle((vm, frame): VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [iter] = unpack_args!(args);
+    let iter = iter.into_iter_fn()?;
+    let mut values = Vec::new();
+    loop {
+        let val = next!(vm, frame, iter)?;
+        if val == Value::Nil { break };
+        values.push(val);
+    }
+    let idx = RefCell::new(0_usize);
+    Ok(iter!(move |_,_| {
+        let i = *idx.borrow();
+        *idx.borrow_mut() += 1;
+        *idx.borrow_mut() %= values.len();
+        Ok(values[i].clone())
+    }))
+}
+
+#[native_func(2)]
+fn take((vm, frame): VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [count, iter] = unpack_args!(args);
+    let iter = iter.into_iter_fn()?;
+    let Value::Int(count) = count else {
+        return error!("take requires an int amount to collect")
+    };
+    let mut values = Vec::new();
+    for _ in 0..count {
+        let val = next!(vm, frame, iter)?;
+        if val == Value::Nil { break };
+        values.push(val);
+    }
+    Ok(Value::List(values.into()))
+}
+
+#[native_func(2)]
+fn last((vm, frame): VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [iter] = unpack_args!(args);
+    let iter = iter.into_iter_fn()?;
+    let mut last = Value::Nil;
+    loop {
+        let val = next!(vm, frame, iter)?;
+        if val == Value::Nil { break };
+        last = val;
+    }
+    Ok(last)
+}
+
+#[native_func(2)]
+fn next((vm, frame): VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [iter] = unpack_args!(args);
+    let iter = iter.into_iter_fn()?;
+    let val = next!(vm, frame, iter)?;
+    Ok(val)
+}
+
+#[native_func(1)]
+fn min((vm, frame): VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [iter] = unpack_args!(args);
+    let iter = iter.into_iter_fn()?;
+    let mut min = Value::Nil;
+    loop {
+        let val = next!(vm, frame, iter)?;
+        if val == Value::Nil { break };
+        if min == Value::Nil || val < min {
+            min = val;
+        }
+    }
+    Ok(min)
+}
+
+#[native_func(1)]
+fn max((vm, frame): VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [iter] = unpack_args!(args);
+    let iter = iter.into_iter_fn()?;
+    let mut max = Value::Nil;
+    loop {
+        let val = next!(vm, frame, iter)?;
+        if val == Value::Nil { break };
+        if max == Value::Nil || val > max {
+            max = val;
+        }
+    }
+    Ok(max)
+}
+
+#[native_func(1)]
+fn rev((vm, frame): VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [iter] = unpack_args!(args);
+    let iter = iter.into_iter_fn()?;
+    let mut values = Vec::new();
+    loop {
+        let val = next!(vm, frame, iter)?;
+        if val == Value::Nil { break };
+        values.push(val);
+    }
+    let values = RefCell::new(values);
+    Ok(iter!(move |_,_| {
+        match values.borrow_mut().pop() {
+            Some(v) => Ok(v),
+            None => Ok(Value::Nil)
+        }
+    }))
+}
+
+#[native_func(1)]
+fn enumerate(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [iter] = unpack_args!(args);
+    let iter = iter.into_iter_fn()?;
+
+    let idx = RefCell::new(0_i64);
+    Ok(iter!(move |(vm, frame),_| {
+        let val = next!(vm, frame, iter)?;
+        if val == Value::Nil {
+            return Ok(Value::Nil)
+        };
+        let curr = *idx.borrow();
+        *idx.borrow_mut() += 1;
+        Ok(Value::List(vec![Value::Int(curr), val].into()))
+    }))
+}
+
+#[native_func(1)]
+fn iterable(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [value] = unpack_args!(args);
+    use Value as V;
+    match value {
+        V::Function(_) |
+            V::List(_) |
+            V::Range(_) |
+            V::Iter(_)
+            => Ok(V::Bool(true)),
+        _ => Ok(V::Bool(false))
+    }
+}
+
+pub fn load(vm: &mut Vm) {
+    vm.load_global_fn(take(), "take");
+    vm.load_global_fn(unzip(), "unzip");
+    vm.load_global_fn(count(), "count");
+    vm.load_global_fn(len(), "len");
+    vm.load_global_fn(sum(), "sum");
+    vm.load_global_fn(min(), "min");
+    vm.load_global_fn(max(), "max");
+    vm.load_global_fn(next(), "next");
+    vm.load_global_fn(last(), "last");
+
+    vm.load_global_fn(list(), "list");
+    vm.load_global_fn(fold(), "fold");
+    vm.load_global_fn(foldi(), "foldi");
+    vm.load_global_fn(scan(), "scan");
+    vm.load_global_fn(chain(), "chain");
+    vm.load_global_fn(lines(), "lines");
+    vm.load_global_fn(skip(), "skip");
+
+    vm.load_global_fn(once(), "once");
+    vm.load_global_fn(iter(), "iter");
+    vm.load_global_fn(range(), "range");
+    vm.load_global_fn(map(), "map");
+    vm.load_global_fn(filter(), "filter");
+    vm.load_global_fn(skip(), "skip");
+    vm.load_global_fn(zip(), "zip");
+    vm.load_global_fn(cycle(), "cycle");
+    vm.load_global_fn(alternate(), "alternate");
+    vm.load_global_fn(intersperse(), "intersperse");
+    vm.load_global_fn(rev(), "rev");
+    vm.load_global_fn(enumerate(), "enumerate");
+
+    vm.load_global_fn(iterable(), "iterable");
+}
diff --git a/matrix-stdlib/src/lib.rs b/matrix-stdlib/src/lib.rs
index 6e0cfc1..334de90 100644
--- a/matrix-stdlib/src/lib.rs
+++ b/matrix-stdlib/src/lib.rs
@@ -1,7 +1,25 @@
-use matrix::vm::Vm;
+use matrix::vm::{Vm, StackFrame};
 
+mod core;
+mod sys;
+mod math;
 mod io;
+mod iter;
+
+pub(crate) type VmArgs<'a, 'b> = (&'a mut Vm, &'b mut StackFrame);
+
+macro_rules! error {
+    ($($arg:tt)*) => {
+        Err(format!($($arg)*).into())
+    };
+}
+
+pub(crate) use error;
 
 pub fn load(vm: &mut Vm) {
+    core::load(vm);
+    sys::load(vm);
     io::load(vm);
+    iter::load(vm);
+    math::load(vm);
 }
diff --git a/matrix-stdlib/src/math.rs b/matrix-stdlib/src/math.rs
new file mode 100644
index 0000000..3226af5
--- /dev/null
+++ b/matrix-stdlib/src/math.rs
@@ -0,0 +1,518 @@
+use core::f64;
+use std::f64::{consts::{PI, E, TAU}, NAN, INFINITY};
+
+use matrix::{vm::Vm, value::{Value, Matrix}, Result, unpack_args, Rational64, Complex64};
+use matrix_macros::native_func;
+use crate::{error, VmArgs};
+
+#[native_func(1)]
+fn trans(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [value] = unpack_args!(args);
+    let mat = match value {
+        Value::Matrix(m) => m,
+        Value::List(l) => Matrix::from_list(l.to_vec()).into(),
+        _ => return error!("trans must be given a matrix")
+    };
+    let values = mat
+        .cols()
+        .reduce(|mut a, b| {a.extend(b); a})
+        .unwrap()
+        .into_iter()
+        .map(|e| e.clone())
+        .collect();
+    Ok(Value::Matrix(Matrix::new(mat.codomain, mat.domain, values).into()))
+}
+
+fn mat_gauss_row_operation(
+    r1: usize,
+    r2: usize,
+    scale: Value,
+    mat: &mut Matrix
+) -> Result<()> {
+    for col in 0..mat.domain {
+        let r1v = mat.get(r1, col)?;
+        let r2v = mat.get(r2, col)?;
+        let res = (r1v - (r2v * scale.clone())?)?;
+        mat.set(r1, col, res)?;
+    }
+    Ok(())
+}
+
+fn mat_swap_rows(
+    r1: usize,
+    r2: usize,
+    mat: &mut Matrix
+) -> Result<()> {
+    let cols = mat.domain;
+    for col in 0..cols {
+        let a = mat.get(r1, col)?;
+        let b = mat.get(r2, col)?;
+        mat.set(r2, col, a)?;
+        mat.set(r1, col, b)?;
+    }
+    Ok(())
+}
+
+fn mat_find_non_zero_col(
+    mat: &Matrix
+) -> Option<usize> {
+    for (i,col) in mat.cols().enumerate() {
+        for val in col.iter() {
+            if **val != Value::Int(0) {
+                return Some(i)
+            }
+        }
+    }
+    return None
+}
+
+fn mat_scale_pivot_row(
+    row: usize,
+    mat: &mut Matrix
+) -> Result<()> {
+    let scale = mat.get(row, row)?;
+    if scale.is_zero() {
+        return Ok(())
+    }
+    for col in 0..mat.domain {
+        let res = (mat.get(row, col)?.clone() / scale.clone())?;
+        mat.set(row, col, res)?;
+    }
+    Ok(())
+}
+
+fn mat_get_non_zero_pivot_row(
+    row: usize,
+    mat: &mut Matrix,
+) -> Result<()> {
+    let col = row;
+    let test = mat.get(row, col)?;
+    if test.is_zero() {
+        for r in row..mat.codomain {
+            let cur = mat.get(r, col)?;
+            if !cur.is_zero() {
+                mat_swap_rows(row, r, mat)?;
+                break;
+            }
+        }
+    }
+    mat_scale_pivot_row(row, mat)?;
+    Ok(())
+}
+
+fn mat_rref(mat: Matrix) -> Result<Matrix> {
+    let mut mat = mat;
+    let Some(start) = mat_find_non_zero_col(&mat) else {
+        return Ok(mat)
+    };
+    let end = mat.domain.min(mat.codomain);
+    for col in start..end {
+        let pivot_row = col;
+        mat_get_non_zero_pivot_row(pivot_row, &mut mat)?;
+        if mat.get(pivot_row, col)?.is_zero() {
+            break
+        }
+        for row in 0..mat.codomain {
+            if row == pivot_row { continue; };
+            let scale = mat.get(row, col)?;
+            mat_gauss_row_operation(row, pivot_row, scale, &mut mat)?;
+        }
+    }
+    Ok(mat)
+}
+
+#[native_func(1)]
+fn rref(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [value] = unpack_args!(args);
+    let mat = match value {
+        Value::Matrix(m) => m,
+        Value::List(l) => Matrix::from_list(l.to_vec()).into(),
+        _ => return error!("trans must be given a matrix")
+    };
+    Ok(Value::Matrix(mat_rref(mat.into_inner())?.into()))
+}
+
+fn mat_det(mat: Matrix) -> Result<Value> {
+    if mat.domain == 1 {
+        return Ok(mat.get(0,0)?)
+    }
+    if mat.domain == 2 {
+        let a = mat.get(0,0)? * mat.get(1,1)?;
+        let b = mat.get(0,1)? * mat.get(1,0)?;
+        return Ok((a? - b?)?)
+    }
+    let mut res = Value::Int(0);
+    for col in 0..mat.domain {
+        let sub_values = mat.rows()
+            .skip(1)
+            .map(|r|
+                 r.into_iter()
+                 .enumerate()
+                 .filter(|(idx,_)| *idx != col)
+                 .map(|(_, v)| v.clone())
+                 .collect::<Vec<Value>>()
+            )
+            .reduce(|mut a, b| {a.extend(b); a})
+            .unwrap();
+        let sub = Matrix::new(mat.domain - 1, mat.domain - 1, sub_values);
+        let val = mat.get(0, col)?;
+        let part = (val * mat_det(sub)?)?;
+        if col % 2 == 0 {
+            res = (res + part)?;
+        } else {
+            res = (res - part)?;
+        }
+    }
+    Ok(res)
+}
+
+#[native_func(1)]
+fn det(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [value] = unpack_args!(args);
+    let mat = match value {
+        Value::Matrix(m) if m.domain == m.codomain => m,
+        Value::List(l) if l.len() == 1 => Matrix::from_list(l.to_vec()).into(),
+        _ => return error!("det requires a square matrix")
+    };
+    let mat = mat.into_inner();
+    Ok(mat_det(mat)?)
+}
+
+fn mat_ident(dim: usize) -> Matrix {
+    let len = dim * dim;
+    let mut values = vec![Value::Int(0); len];
+    let mut idx = 0;
+    loop {
+        if idx >= len { break };
+        values[idx] = Value::Int(1);
+        idx += dim + 1;
+    }
+    Matrix::new(dim, dim, values)
+}
+
+#[native_func(1)]
+fn ident(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [value] = unpack_args!(args);
+    let dim = match value {
+        Value::Int(i) if i > 0 => i,
+        Value::Ratio(r)
+            if *r.denom() == 1 &&
+               *r.numer() > 0
+                => *r.numer(),
+        _ => return error!("ident requries a positive [Int] dimension")
+    };
+    Ok(Value::Matrix(mat_ident(dim as usize).into()))
+}
+
+fn mat_splith(mat: Matrix) -> (Matrix, Matrix) {
+    let mut m1 = Vec::new();
+    let mut m2 = Vec::new();
+
+    mat.rows()
+        .for_each(|r| {
+            let split = r.len() / 2;
+            r.into_iter().enumerate().for_each(|(i, v)| {
+                if i < split {
+                    m1.push(v.clone());
+                } else {
+                    m2.push(v.clone());
+                }
+            })
+        });
+
+    let m1 = Matrix::new(mat.domain/2, mat.codomain, m1);
+    let m2 = Matrix::new(mat.domain/2, mat.codomain, m2);
+    (m1, m2)
+}
+
+#[native_func(1)]
+fn inv(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [value] = unpack_args!(args);
+    let mat = match value {
+        Value::Matrix(m) if m.domain == m.codomain => m,
+        Value::List(l) if l.len() == 1 => Matrix::from_list(l.to_vec()).into(),
+        _ => return error!("det requires a square matrix")
+    };
+    let mat = mat.into_inner();
+    let ident = mat_ident(mat.domain);
+    let joined = mat.join_right(&ident)?;
+    let refed = mat_rref(joined)?;
+    let (new_ident, new_inv) = mat_splith(refed);
+
+    if new_ident == ident {
+        Ok(Value::Matrix(new_inv.into()))
+    } else {
+        error!("matrix does not have an inverse")
+    }
+}
+
+macro_rules! mathr {
+    ($type:ident) => {
+        #[native_func(1)]
+        fn $type(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+            use Value as V;
+            let [value] = unpack_args!(args);
+            match value {
+                V::Int(i) => Ok(V::Int(i)),
+                V::Ratio(r) => Ok(V::Ratio(r.$type())),
+                V::Float(f) => Ok(V::Float(f.$type())),
+                v => error!("cannot compute {} on {v}", stringify!($type))
+            }
+        }
+    };
+}
+
+macro_rules! trig {
+    ($type:ident) => {
+        #[native_func(1)]
+        fn $type(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+            use Value as V;
+            let [value] = unpack_args!(args);
+            match value.promote_trig() {
+                V::Float(f) => Ok(V::Float(f.$type())),
+                V::Complex(c) => Ok(V::Complex(c.$type())),
+                v => error!("cannot compute {} on {v}", stringify!($type))
+            }
+        }
+    };
+}
+
+macro_rules! trigf {
+    ($type:ident, $str:ident) => {
+        #[native_func(1)]
+        fn $str(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+            use Value as V;
+            let [value] = unpack_args!(args);
+            match value.promote_trig() {
+                V::Float(f) => Ok(V::Float(f.$type())),
+                v => error!("cannot compute {} on {v}", stringify!($str))
+            }
+        }
+    };
+}
+
+#[native_func(2)]
+fn log(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    use Value as V;
+    let [base, value] = unpack_args!(args);
+    match (base.promote_trig(), value.promote_trig()) {
+        (V::Float(base), V::Float(arg)) => Ok(V::Float(arg.log(base))),
+        (V::Float(base), V::Complex(arg)) => Ok(V::Complex(arg.log(base))),
+        (V::Complex(base), V::Float(arg)) => Ok(V::Complex(arg.ln() / base.ln())),
+        (V::Complex(base), V::Complex(arg)) => Ok(V::Complex(arg.ln() / base.ln())),
+        (base, arg) => error!("cannot compute log base {base} argument {arg}")
+    }
+}
+
+#[native_func(1)]
+fn abs(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    use Value as V;
+    let [value] = unpack_args!(args);
+    match value {
+        V::Int(i) => Ok(V::Int(i.abs())),
+        V::Float(f) => Ok(V::Float(f.abs())),
+        V::Ratio(r) => Ok(V::Ratio(Rational64::new(r.numer().abs(), r.denom().abs()))),
+        V::Complex(c) => Ok(V::Float(c.norm())),
+        arg => error!("cannot compute abs for {arg}")
+    }
+}
+
+#[native_func(1)]
+fn fract(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    use Value as V;
+    let [value] = unpack_args!(args);
+    match value {
+        V::Int(_) => Ok(V::Int(0)),
+        V::Float(f) => Ok(V::Float(f.fract())),
+        V::Ratio(r) => Ok(V::Ratio(r.fract())),
+        arg => error!("cannot compute fract for {arg}")
+    }
+}
+
+#[native_func(1)]
+fn sign(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    use Value as V;
+    let [value] = unpack_args!(args);
+    match value {
+        V::Int(i) => Ok(V::Int(i.signum())),
+        V::Ratio(r) => Ok(V::Int(r.numer().signum())),
+        V::Float(f) => Ok(V::Float(f.signum())),
+        arg => error!("cannot compute sign for {arg}")
+    }
+}
+
+#[native_func(1)]
+fn int(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    use Value as V;
+    let [value] = unpack_args!(args);
+    match value {
+        V::Int(i) => Ok(V::Int(i)),
+        V::Ratio(r) => Ok(V::Int(r.numer() / r.denom())),
+        V::Float(f) => Ok(V::Int(f as i64)),
+        V::Complex(c) => Ok(V::Int(c.re as i64)),
+        arg => error!("cannot cast {arg} to int")
+    }
+}
+
+#[native_func(1)]
+fn ratio(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    use Value as V;
+    let [value] = unpack_args!(args);
+    match value {
+        V::Int(i) => Ok(V::Ratio(Rational64::new(i, 1))),
+        V::Ratio(r) => Ok(V::Ratio(r)),
+        V::Float(f) => Ok(V::Ratio(Rational64::approximate_float(f).unwrap_or(Rational64::new(0, 1)))),
+        V::Complex(c) => Ok(V::Ratio(Rational64::approximate_float(c.re).unwrap_or(Rational64::new(0, 1)))),
+        arg => error!("cannot cast {arg} to ratio")
+    }
+}
+
+#[native_func(1)]
+fn float(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    use Value as V;
+    let [value] = unpack_args!(args);
+    match value {
+        V::Int(i) => Ok(V::Float(i as f64)),
+        V::Ratio(r) => Ok(V::Float((*r.numer() as f64) / (*r.denom() as f64))),
+        V::Float(f) => Ok(V::Float(f)),
+        V::Complex(c) => Ok(V::Float(c.re)),
+        arg => error!("cannot cast {arg} to float")
+    }
+}
+
+#[native_func(1)]
+fn complex(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    use Value as V;
+    let [value] = unpack_args!(args);
+    match value {
+        V::Int(i) => Ok(V::Complex(Complex64::new(i as f64, 0.0))),
+        V::Ratio(r) => Ok(V::Complex(Complex64::new((*r.numer() as f64) / (*r.denom() as f64), 0.0))),
+        V::Float(f) => Ok(V::Complex(Complex64::new(f, 0.0))),
+        V::Complex(c) => Ok(V::Complex(c)),
+        arg => error!("cannot cast {arg} to float")
+    }
+}
+
+#[native_func(1)]
+fn numer(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    use Value as V;
+    let [value] = unpack_args!(args);
+    match value {
+        V::Int(i) => Ok(V::Int(i)),
+        V::Ratio(r) => Ok(V::Int(*r.numer())),
+        _ => error!("numer can only take a integer or ratio")
+    }
+}
+
+#[native_func(1)]
+fn denom(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    use Value as V;
+    let [value] = unpack_args!(args);
+    match value {
+        V::Int(_) => Ok(V::Int(1)),
+        V::Ratio(r) => Ok(V::Int(*r.denom())),
+        _ => error!("denom can only take a integer or ratio")
+    }
+}
+
+#[native_func(1)]
+fn re(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    use Value as V;
+    let [value] = unpack_args!(args);
+    match value {
+        V::Int(_) | V::Ratio(_) | V::Float(_) => Ok(value),
+        V::Complex(c) => Ok(V::Float(c.re)),
+        _ => error!("re can only take a valid number")
+    }
+}
+
+#[native_func(1)]
+fn im(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    use Value as V;
+    let [value] = unpack_args!(args);
+    match value {
+        V::Int(_) | V::Ratio(_) | V::Float(_ )=> Ok(V::Int(0)),
+        V::Complex(c) => Ok(V::Float(c.im)),
+        _ => error!("re can only take a valid number")
+    }
+}
+
+mathr!(floor);
+mathr!(ceil);
+mathr!(round);
+mathr!(trunc);
+trig!(sqrt);
+trig!(cbrt);
+trig!(ln);
+trig!(log2);
+trig!(log10);
+trig!(exp);
+trig!(exp2);
+trig!(sin);
+trig!(cos);
+trig!(tan);
+trig!(sinh);
+trig!(cosh);
+trig!(tanh);
+trig!(asin);
+trig!(acos);
+trig!(atan);
+trig!(asinh);
+trig!(acosh);
+trig!(atanh);
+trigf!(to_degrees, deg);
+trigf!(to_radians, rad);
+
+pub fn load(vm: &mut Vm) {
+    vm.load_global_fn(trans(), "trans");
+    vm.load_global_fn(rref(), "rref");
+    vm.load_global_fn(det(), "det");
+    vm.load_global_fn(ident(), "ident");
+    vm.load_global_fn(inv(), "inv");
+
+    vm.load_global(Value::Float(PI), "pi");
+    vm.load_global(Value::Float(TAU), "tau");
+    vm.load_global(Value::Float(E), "e");
+    vm.load_global(Value::Float(NAN), "nan");
+    vm.load_global(Value::Float(NAN), "NaN");
+    vm.load_global(Value::Float(INFINITY), "inf");
+
+    vm.load_global_fn(int(), "int");
+    vm.load_global_fn(ratio(), "ratio");
+    vm.load_global_fn(float(), "float");
+    vm.load_global_fn(complex(), "complex");
+    vm.load_global_fn(abs(), "abs");
+    vm.load_global_fn(sign(), "sign");
+    vm.load_global_fn(floor(), "floor");
+    vm.load_global_fn(ceil(), "ceil");
+    vm.load_global_fn(round(), "round");
+    vm.load_global_fn(trunc(), "trunc");
+    vm.load_global_fn(fract(), "fract");
+    vm.load_global_fn(sqrt(), "sqrt");
+    vm.load_global_fn(cbrt(), "cbrt");
+    vm.load_global_fn(ln(), "ln");
+    vm.load_global_fn(log(), "log");
+    vm.load_global_fn(log2(), "log2");
+    vm.load_global_fn(log10(), "log10");
+    vm.load_global_fn(exp(), "exp");
+    vm.load_global_fn(exp2(), "exp2");
+    vm.load_global_fn(sin(), "sin");
+    vm.load_global_fn(cos(), "cos");
+    vm.load_global_fn(tan(), "tan");
+    vm.load_global_fn(sinh(), "sinh");
+    vm.load_global_fn(cosh(), "cosh");
+    vm.load_global_fn(tanh(), "tanh");
+    vm.load_global_fn(asin(), "asin");
+    vm.load_global_fn(acos(), "acos");
+    vm.load_global_fn(atan(), "atan");
+    vm.load_global_fn(asinh(), "asinh");
+    vm.load_global_fn(acosh(), "acosh");
+    vm.load_global_fn(atanh(), "atanh");
+    vm.load_global_fn(deg(), "deg");
+    vm.load_global_fn(rad(), "rad");
+
+    vm.load_global_fn(denom(), "denom");
+    vm.load_global_fn(numer(), "numer");
+    vm.load_global_fn(re(), "re");
+    vm.load_global_fn(im(), "im");
+}
diff --git a/matrix-stdlib/src/sys.rs b/matrix-stdlib/src/sys.rs
new file mode 100644
index 0000000..e91e635
--- /dev/null
+++ b/matrix-stdlib/src/sys.rs
@@ -0,0 +1,99 @@
+use std::{process::{exit, Command, Stdio}, env, rc::Rc, io::Read};
+
+use matrix::{vm::Vm, value::{Value, ValueMap}, unpack_args, Result, gc::Gc};
+use matrix_macros::native_func;
+use crate::{VmArgs, error};
+
+#[native_func(1)]
+fn sys_exit(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [value] = unpack_args!(args);
+    let Value::Int(i) = value else {
+        return error!("exit requires a int exit code")
+    };
+    exit(i as i32);
+}
+
+#[native_func(0)]
+fn argv(_: VmArgs, _: Vec<Value>) -> Result<Value> {
+    Ok(Value::List(
+            Gc::new(
+                env::args()
+                .map(|a| Value::String(Rc::from(a.as_str())))
+                .collect()
+    )))
+}
+
+#[native_func(1)]
+fn env(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [value] = unpack_args!(args);
+    let Value::String(value) = value else {
+        return error!("env requires a string name")
+    };
+    match std::env::var(value.as_ref()) {
+        Ok(v) => Ok(Value::String(v.into())),
+        Err(e) => error!("couldn't read env var: {e}")
+    }
+}
+
+#[native_func(2)]
+fn exec(_: VmArgs, args: Vec<Value>) -> Result<Value> {
+    let [cmd, args] = unpack_args!(args);
+    let (cmd, args) = match (cmd, args) {
+        (Value::String(s), Value::List(l)) => (s, l.into_inner()),
+        _ => return error!("exec requires a string cmd and string argument list")
+    };
+    let mut sargs = Vec::new();
+    for arg in args {
+        let Value::String(arg) = arg else {
+            return error!("exec requires a string cmd and string argument list")
+        };
+        sargs.push(arg.to_string());
+    };
+    let cmd = Command::new(cmd.to_string())
+        .args(sargs)
+        .stdin(Stdio::piped())
+        .stdout(Stdio::piped())
+        .stderr(Stdio::piped())
+        .spawn();
+    let mut child = match cmd {
+        Ok(c) => c,
+        Err(e) => return error!("error executing command: {e}")
+    };
+    let status = match child.wait() {
+        Ok(s) => s,
+        Err(e) => return error!("error executing command: {e}")
+    };
+
+    let stdout = match child.stdout {
+        Some(ref mut out) => {
+            let mut buf = String::new();
+            let _ = out.read_to_string(&mut buf);
+            buf
+        },
+        None => String::new()
+    };
+
+    let stderr = match child.stderr {
+        Some(ref mut err) => {
+            let mut buf = String::new();
+            let _ = err.read_to_string(&mut buf);
+            buf
+        },
+        None => String::new()
+    };
+
+    let mut res = ValueMap::new();
+    res.insert(Value::from("success"), Value::Bool(status.success()))?;
+    res.insert(Value::from("code"), Value::Int(status.code().unwrap_or(0) as i64))?;
+    res.insert(Value::from("out"), Value::String(stdout.into()))?;
+    res.insert(Value::from("err"), Value::String(stderr.into()))?;
+
+    Ok(Value::Table(res.into()))
+}
+
+pub fn load(vm: &mut Vm) {
+    vm.load_global_fn(sys_exit(), "exit");
+    vm.load_global_fn(argv(), "argv");
+    vm.load_global_fn(exec(), "exec");
+    vm.load_global_fn(env(), "env");
+}
diff --git a/matrix/src/ast.rs b/matrix/src/ast.rs
index 68e325e..de63630 100644
--- a/matrix/src/ast.rs
+++ b/matrix/src/ast.rs
@@ -1,5 +1,5 @@
-use std::{rc::Rc, ops::{Neg, Not}};
-use crate::{lex::Token, value::{Value, InlineList, InlineMatrix, InlineTable}, Result};
+use std::{rc::Rc, ops::{Neg, Not}, fmt::Debug};
+use crate::{lex::{Position, TokenData}, value::{Value, InlineList, InlineMatrix, InlineTable}, Result};
 
 #[derive(Debug, Clone, Copy, Eq, PartialEq)]
 pub enum UnaryOp {
@@ -31,10 +31,15 @@ pub enum BinaryOp {
     LessEquals,
     GreaterThan,
     LessThan,
+    // iter
+    Range,
+    RangeEq
 }
 
+pub type AstName = (Rc<str>, Position);
+
 #[derive(Debug, Clone, PartialEq)]
-pub enum Expr {
+pub enum ExprData {
     NoOp,
 
     Literal(Value),
@@ -45,7 +50,7 @@ pub enum Expr {
 
     Index(Box<Expr>, Vec<Expr>),
     FnCall(Box<Expr>, Vec<Expr>),
-    FieldAccess(Box<Expr>, Rc<str>),
+    FieldAccess(Box<Expr>, AstName),
 
     List(InlineList),
     Matrix(InlineMatrix),
@@ -57,22 +62,49 @@ pub enum Expr {
     Assign(Box<Expr>, Box<Expr>),
 
     If(Box<Expr>, Box<Expr>, Option<Box<Expr>>),
-    Function(Rc<str>, Vec<Rc<str>>, Box<Expr>, bool),
-    Lambda(Vec<Rc<str>>, Box<Expr>, bool),
+    Function(AstName, Vec<AstName>, Box<Expr>, bool),
+    Lambda(Vec<AstName>, Box<Expr>, bool),
 
     Loop(Box<Expr>),
     While(Box<Expr>, Box<Expr>),
     DoWhile(Box<Expr>, Box<Expr>),
+    For(AstName, Box<Expr>, Box<Expr>),
 
     Block(Vec<Expr>),
 
-    Let(Rc<str>, Box<Expr>),
+    Try(Box<Expr>, AstName, Box<Expr>),
+
+    Let(AstName, Box<Expr>),
+
+    Pipeline(Box<Expr>, Box<Expr>),
 
     Continue,
     Break,
     Return(Box<Expr>),
 }
 
+#[derive(Clone, PartialEq)]
+pub struct Expr {
+    pub data: ExprData,
+    pub pos: Position
+}
+
+impl Debug for Expr {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        if f.alternate() {
+            write!(f, "{:#?}", self.data)
+        } else {
+            write!(f, "{:?}", self.data)
+        }
+    }
+}
+
+impl From<(ExprData, Position)> for Expr {
+    fn from(value: (ExprData, Position)) -> Self {
+        Self { data: value.0, pos: value.1 }
+    }
+}
+
 impl Neg for BinaryOp {
     type Output = Option<Self>;
     fn neg(self) -> Self::Output {
@@ -103,73 +135,94 @@ impl Not for BinaryOp {
 
 impl Neg for Expr {
     type Output = std::result::Result<Self, Self>;
-    fn neg(self) -> Self::Output {
-        use Expr::*;
-        Ok(match self {
-            Literal(v) => Literal(-v),
-            BinaryOp(lhs, rhs, op) => {
+    fn neg(mut self) -> Self::Output {
+        use ExprData as E;
+        let mut pos = self.pos;
+        let data = match self.data {
+            E::Literal(v) => E::Literal(-v),
+            E::BinaryOp(lhs, rhs, op) => {
                 let Some(op_n) = -op else {
-                    return Err(BinaryOp(lhs, rhs, op));
+                    return Err((E::BinaryOp(lhs, rhs, op), pos).into());
                 };
                 if let Ok(lhs) = -*lhs.clone() {
-                    BinaryOp(Box::new(lhs), rhs, op_n)
+                    pos = lhs.pos;
+                    E::BinaryOp(Box::new(lhs), rhs, op_n)
                 } else if let Ok(rhs) = -*rhs.clone() {
-                    BinaryOp(lhs, Box::new(rhs), op_n)
+                    pos = rhs.pos;
+                    E::BinaryOp(lhs, Box::new(rhs), op_n)
                 } else {
-                    return Err(BinaryOp(lhs, rhs, op))
+                    return Err((E::BinaryOp(lhs, rhs, op), pos).into());
                 }
             },
-            UnaryOp(expr, op) => {
+            E::UnaryOp(expr, op) => {
                 match op {
-                    self::UnaryOp::Negate => *expr,
-                    _ => return Err(UnaryOp(expr, op))
+                    UnaryOp::Negate => {
+                        pos = expr.pos;
+                        expr.data
+                    },
+                    _ => return Err((E::UnaryOp(expr, op), pos).into())
                 }
             }
-            _ => return Err(self)
-        })
+            data => return Err((data, pos).into())
+        };
+        self.data = data;
+        self.pos = pos;
+        Ok(self)
     }
 }
 
 impl Not for Expr {
     type Output = std::result::Result<Self, Self>;
-    fn not(self) -> Self::Output {
-        use Expr::*;
-        Ok(match self {
-            Literal(v) => Literal(Value::Bool(!v)),
-            UnaryOp(expr, op) => {
+    fn not(mut self) -> Self::Output {
+        use ExprData as E;
+        let mut pos = self.pos;
+        let data = match self.data {
+            E::Literal(v) => E::Literal(Value::Bool(!v)),
+            E::UnaryOp(expr, op) => {
                 match op {
-                    self::UnaryOp::Not => *expr,
-                    _ => return Err(UnaryOp(expr, op))
+                    self::UnaryOp::Not => {
+                        pos = expr.pos;
+                        expr.data
+                    },
+                    _ => return Err((E::UnaryOp(expr, op), pos).into())
                 }
             }
-            _ => return Err(self)
-        })
+            data => return Err((data, pos).into())
+        };
+        self.data = data;
+        self.pos = pos;
+        Ok(self)
     }
 }
 
-pub fn optimize(expr: Expr) -> Result<Expr> {
-    use Expr as E;
-    Ok(match expr {
+pub fn optimize(mut expr: Expr) -> Result<Expr> {
+    use ExprData as E;
+    let mut pos = expr.pos;
+    let data: ExprData = match expr.data {
         E::UnaryOp(expr, op) => {
             let expr = optimize(*expr)?;
             match match op {
                 UnaryOp::Negate => -expr,
                 UnaryOp::Not => !expr,
             } {
-                Ok(expr) => expr,
+                Ok(expr) => {
+                    pos = expr.pos;
+                    expr.data
+                },
                 Err(expr) => E::UnaryOp(Box::new(expr), op)
             }
         },
         E::BinaryOp(lhs, rhs, op) => {
             let lhs = optimize(*lhs)?;
             let rhs = optimize(*rhs)?;
-            if let (E::Literal(l), E::Literal(r)) = (lhs.clone(), rhs.clone()) {
+            if let (E::Literal(l), E::Literal(r)) = (lhs.clone().data, rhs.clone().data) {
                 match Value::binary_op(op, l, r) {
                     Err(err) => return Err(err),
-                    Ok(value) => return Ok(Expr::Literal(value)),
+                    Ok(value) => E::Literal(value),
                 }
+            } else {
+                E::BinaryOp(Box::new(lhs), Box::new(rhs), op)
             }
-            E::BinaryOp(Box::new(lhs), Box::new(rhs), op)
         },
         E::FnCall(ident, values) => {
             E::FnCall(ident, values
@@ -200,10 +253,16 @@ pub fn optimize(expr: Expr) -> Result<Expr> {
         E::And(lhs, rhs) => {
             let lhs = optimize(*lhs)?;
             let rhs = optimize(*rhs)?;
-            if let (E::Literal(l), r) = (lhs.clone(), rhs.clone()) {
+            if let (E::Literal(l), r) = (lhs.clone().data, rhs.clone().data) {
                 match !!l.clone() {
-                    true => r,
-                    false => E::Literal(l),
+                    true => {
+                        pos = rhs.pos;
+                        r
+                    },
+                    false => {
+                        pos = lhs.pos;
+                        E::Literal(l)
+                    },
                 }
             } else {
                 E::And(Box::new(lhs), Box::new(rhs))
@@ -212,10 +271,16 @@ pub fn optimize(expr: Expr) -> Result<Expr> {
         E::Or(lhs, rhs) => {
             let lhs = optimize(*lhs)?;
             let rhs = optimize(*rhs)?;
-            if let (E::Literal(l), r) = (lhs.clone(), rhs.clone()) {
+            if let (E::Literal(l), r) = (lhs.clone().data, rhs.clone().data) {
                 match !l.clone() {
-                    true => r,
-                    false => E::Literal(l),
+                    true => {
+                        pos = rhs.pos;
+                        r
+                    },
+                    false => {
+                        pos = lhs.pos;
+                        E::Literal(l)
+                    },
                 }
             } else {
                 E::And(Box::new(lhs), Box::new(rhs))
@@ -230,10 +295,10 @@ pub fn optimize(expr: Expr) -> Result<Expr> {
                 .into_iter()
                 .enumerate()
                 .filter(|(i, e)| {
-                    if let E::Literal(_) = e {
+                    if let E::Literal(_) = e.data {
                         return i + 1 == len
                     }
-                    E::NoOp != *e
+                    E::NoOp != e.data
                 })
                 .map(|e| e.1)
                 .collect();
@@ -247,39 +312,60 @@ pub fn optimize(expr: Expr) -> Result<Expr> {
             let cond = optimize(*cond)?;
             let block = optimize(*block)?;
             let else_block = else_block.map(|e| optimize(*e)).transpose()?;
-            if let E::Literal(lit) = cond {
+            if let E::Literal(lit) = cond.data {
                 if !!lit {
-                    return Ok(block)
+                    pos = block.pos;
+                    block.data
+                } else if let Some(else_block) = else_block {
+                    pos = else_block.pos;
+                    else_block.data
+                } else {
+                    E::NoOp
                 }
-                return Ok(else_block.unwrap_or(E::NoOp))
+            } else {
+                E::If(Box::new(cond), Box::new(block), else_block.map(|e| Box::new(e)))
             }
-            E::If(Box::new(cond), Box::new(block), else_block.map(|e| Box::new(e)))
         },
         E::While(cond, block) => {
             let cond = optimize(*cond)?;
             let block = optimize(*block)?;
-            if let E::Literal(lit) = cond {
+            if let E::Literal(lit) = cond.data {
                 if !!lit {
-                    return Ok(E::Loop(Box::new(block)))
+                    E::Loop(Box::new(block))
+                } else {
+                    E::NoOp
                 }
-                return Ok(E::NoOp)
+            } else {
+                E::While(Box::new(cond), Box::new(block))
             }
-            E::While(Box::new(cond), Box::new(block))
         },
+        E::For(name, cond, block) => {
+            let cond = optimize(*cond)?;
+            let block = optimize(*block)?;
+            E::For(name, Box::new(cond), Box::new(block))
+        }
         E::DoWhile(block, cond) => {
             let cond = optimize(*cond)?;
             let block = optimize(*block)?;
-            if let E::Literal(lit) = cond.clone() {
-                if !!lit {
-                    return Ok(E::Loop(Box::new(block)))
+            if let E::Literal(lit) = &cond.data {
+                if !!lit.clone() {
+                    E::Loop(Box::new(block))
+                } else {
+                    E::DoWhile(Box::new(block), Box::new(cond))
                 }
+            } else {
+                E::DoWhile(Box::new(block), Box::new(cond))
             }
-            E::DoWhile(Box::new(block), Box::new(cond))
         }
         E::Loop(block) => {
             let block = Box::new(optimize(*block)?);
             E::Loop(block)
         },
+        E::Try(expr, err, catch) => {
+            let expr = Box::new(optimize(*expr)?);
+            let catch = Box::new(optimize(*catch)?);
+            E::Try(expr, err, catch)
+        },
         E::Function(ident, params, stmt, varadic) => {
             let stmt = Box::new(optimize(*stmt)?);
             E::Function(ident, params, stmt, varadic)
@@ -297,44 +383,53 @@ pub fn optimize(expr: Expr) -> Result<Expr> {
             E::Assign(lhs, rhs)
         },
         E::Return(expr) => {
-            E::Return(Box::new(optimize(*expr)?))
+            let expr = Box::new(optimize(*expr)?);
+            E::Return(expr)
         },
-        _ => expr
-    })
+        E::Pipeline(lhs, rhs) => {
+            let lhs = Box::new(optimize(*lhs)?);
+            let rhs = Box::new(optimize(*rhs)?);
+            E::Pipeline(lhs, rhs)
+        }
+        data => data
+    };
+    expr.data = data;
+    expr.pos = pos;
+    Ok(expr)
 }
 
-impl From<Token> for UnaryOp {
-    fn from(value: Token) -> Self {
-        use Token::*;
+impl From<TokenData> for UnaryOp {
+    fn from(value: TokenData) -> Self {
+        use TokenData as T;
         match value {
-            Subtract => Self::Negate,
-            Not => Self::Not,
+            T::Subtract => Self::Negate,
+            T::Not => Self::Not,
             _ => panic!("aaaaa")
         }
     }
 }
 
-impl From<Token> for BinaryOp {
-    fn from(value: Token) -> Self {
-        use Token::*;
+impl From<TokenData> for BinaryOp {
+    fn from(value: TokenData) -> Self {
+        use TokenData as T;
         match value {
-            Equal => Self::Equals,
-            NotEqual => Self::NotEquals,
-            GreaterEqual => Self::GreaterEquals,
-            LessEqual => Self::LessEquals,
-            GreaterThan => Self::GreaterThan,
-            LessThan => Self::LessThan,
-            BitwiseShiftLeft => Self::BitwiseShiftLeft,
-            BitwiseShiftRight => Self::BitwiseShiftRight,
-            BitwiseAnd => Self::BitwiseAnd,
-            BitwiseOr => Self::BitwiseOr,
-            BitwiseXor => Self::BitwiseXor,
-            Add => Self::Add,
-            Subtract => Self::Subtract,
-            Multiply => Self::Multiply,
-            Divide => Self::Divide,
-            Modulo => Self::Modulo,
-            Power => Self::Power,
+            T::Equal => Self::Equals,
+            T::NotEqual => Self::NotEquals,
+            T::GreaterEqual => Self::GreaterEquals,
+            T::LessEqual => Self::LessEquals,
+            T::GreaterThan => Self::GreaterThan,
+            T::LessThan => Self::LessThan,
+            T::BitwiseShiftLeft => Self::BitwiseShiftLeft,
+            T::BitwiseShiftRight => Self::BitwiseShiftRight,
+            T::BitwiseAnd => Self::BitwiseAnd,
+            T::BitwiseOr => Self::BitwiseOr,
+            T::BitwiseXor => Self::BitwiseXor,
+            T::Add => Self::Add,
+            T::Subtract => Self::Subtract,
+            T::Multiply => Self::Multiply,
+            T::Divide => Self::Divide,
+            T::Modulo => Self::Modulo,
+            T::Power => Self::Power,
             _ => panic!("aaaaa")
         }
     }
@@ -342,11 +437,11 @@ impl From<Token> for BinaryOp {
 
 impl Expr {
     pub fn is_assignable(&self) -> bool {
-        use Expr::*;
-        match self {
-            Ident(_) => true,
-            Index(_, _) => true,
-            FieldAccess(_, _) => true,
+        use ExprData as E;
+        match self.data {
+            E::Ident(_) => true,
+            E::Index(_, _) => true,
+            E::FieldAccess(_, _) => true,
             _ => false,
         }
     }
diff --git a/matrix/src/chunk.rs b/matrix/src/chunk.rs
index 19ff8e6..495b787 100644
--- a/matrix/src/chunk.rs
+++ b/matrix/src/chunk.rs
@@ -1,17 +1,19 @@
-use crate::{value::Value, ast::{UnaryOp, BinaryOp}, vm::Vm, Result};
+use crate::{value::Value, ast::{UnaryOp, BinaryOp}, vm::{Vm, StackFrame}, Result, lex::Position};
 use std::{fmt::{Debug, Display}, rc::Rc};
 
-#[derive(Clone)]
+#[derive(Clone, Default)]
 pub struct Chunk {
     pub constants: Vec<Value>,
-    pub code: Vec<Instruction>
+    pub code: Vec<Instruction>,
+    pub pos: Vec<Position>,
 }
 
 impl Chunk {
     pub fn new() -> Self {
         Self {
             constants: Vec::new(),
-            code: Vec::new()
+            code: Vec::new(),
+            pos: Vec::new(),
         }
     }
 }
@@ -43,9 +45,10 @@ pub struct Function {
     pub fun: InnerFunction
 }
 
+#[derive(Clone)]
 pub enum InnerFunction {
     Compiled(Rc<Chunk>),
-    Native(Box<dyn Fn(&mut Vm, Vec<Value>) -> Result<Value>>),
+    Native(Rc<dyn Fn((&mut Vm, &mut StackFrame), Vec<Value>) -> Result<Value>>),
 }
 
 impl Debug for Function {
@@ -98,6 +101,13 @@ pub enum Instruction {
     Jump(u16),
     JumpTrue(u16),
     JumpFalse(u16),
+    JumpNil(u16),
+
+    IterCreate,
+    IterNext,
+
+    Try(u16),
+    TryEnd,
 
     Call(u8),
     Return,
@@ -131,10 +141,15 @@ impl Display for Instruction {
             Jump(idx) => write!(f, "jump \x1b[33m{idx}\x1b[0m"),
             JumpTrue(idx) => write!(f, "jumpt \x1b[33m{idx}\x1b[0m"),
             JumpFalse(idx) => write!(f, "jumpf \x1b[33m{idx}\x1b[0m"),
+            JumpNil(idx) => write!(f, "jumpn \x1b[33m{idx}\x1b[0m"),
             Call(arity) => write!(f, "call \x1b[35m{arity}\x1b[0m"),
             Return => write!(f, "return"),
+            IterCreate => write!(f, "iter create"),
+            IterNext => write!(f, "iter next"),
             Field(name_idx) => write!(f, "field \x1b[33m{name_idx}\x1b[0m"),
             StoreField(name_idx) => write!(f, "store field \x1b[33m{name_idx}\x1b[0m"),
+            Try(idx) => write!(f, "try \x1b[33m{idx}\x1b[0m"),
+            TryEnd => write!(f, "try end"),
         }
     }
 }
diff --git a/matrix/src/compiler.rs b/matrix/src/compiler.rs
index a516807..6b6a94b 100644
--- a/matrix/src/compiler.rs
+++ b/matrix/src/compiler.rs
@@ -1,9 +1,9 @@
 use std::{fmt::Display, rc::Rc, cell::RefCell};
-use crate::{ast::Expr, chunk::{Function, Instruction, InnerFunction}, chunk::{Chunk, self}, value::Value, Result};
+use crate::{ast::{Expr, ExprData, AstName}, chunk::{Function, Instruction, InnerFunction}, chunk::{Chunk, self}, value::Value, Result, lex::Position};
 
 use Instruction as I;
 use Value as V;
-use Expr as E;
+use ExprData as E;
 
 pub type NamesTable = Rc<RefCell<Vec<Rc<str>>>>;
 
@@ -104,7 +104,7 @@ struct Local {
 }
 
 #[derive(Debug, Clone)]
-pub enum Error {
+pub enum InnerError {
     Undefined(Rc<str>),
     Redefined(Rc<str>),
     InvAssign(Expr),
@@ -113,22 +113,36 @@ pub enum Error {
     NotImplemented(&'static str),
 }
 
+#[derive(Debug, Clone)]
+pub struct Error {
+    pos: Position,
+    err: InnerError,
+}
+
 impl std::error::Error for self::Error {}
 
 impl Display for self::Error {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        use self::Error::*;
-        match self {
-            Undefined(name) => write!(f, "value {name} is undefined"),
-            Redefined(name) => write!(f, "cannot redefine {name} in the same scope"),
-            InvAssign(expr) => write!(f, "cannot assign to {expr:?}"),
-            InvContinue => write!(f, "cannot continue outside a loop"),
-            InvBreak => write!(f, "cannot break outside a loop"),
-            NotImplemented(str) => write!(f, "{str} is not implemented yet")
+        use InnerError as E;
+        write!(f, "parse failed at {}:{}, ", self.pos.row, self.pos.col)?;
+        match &self.err {
+            E::Undefined(name) => write!(f, "value {name} is undefined"),
+            E::Redefined(name) => write!(f, "cannot redefine {name} in the same scope"),
+            E::InvAssign(expr) => write!(f, "cannot assign to {expr:?}"),
+            E::InvContinue => write!(f, "cannot continue outside a loop"),
+            E::InvBreak => write!(f, "cannot break outside a loop"),
+            E::NotImplemented(str) => write!(f, "{str} is not implemented yet")
         }
     }
 }
 
+fn error<T>(err: InnerError, pos: Position) -> Result<T> {
+    Err(self::Error {
+        pos,
+        err
+    }.into())
+}
+
 impl<'c> Compiler<'c> {
 
     fn child(&'c self, name: Rc<str>) -> Self {
@@ -156,7 +170,7 @@ impl<'c> Compiler<'c> {
             cutoff = self.scopes.pop().unwrap()
         }
         if cutoff < self.locals.len() {
-            self.emit(Instruction::DiscardLocals((self.locals.len() - cutoff) as u16));
+            self.emit(Instruction::DiscardLocals((self.locals.len() - cutoff) as u16), self.last_pos());
             self.locals.truncate(cutoff);
         };
     }
@@ -166,7 +180,7 @@ impl<'c> Compiler<'c> {
             return;
         };
         if cutoff < self.locals.len() {
-            self.emit(Instruction::DiscardLocals((self.locals.len() - cutoff) as u16));
+            self.emit(Instruction::DiscardLocals((self.locals.len() - cutoff) as u16), self.last_pos());
             self.locals.truncate(cutoff);
         };
     }
@@ -182,19 +196,19 @@ impl<'c> Compiler<'c> {
         c
     }
 
-    fn create_local_checked(&mut self, name: Rc<str>) -> Result<()> {
+    fn create_local_checked(&mut self, name: Rc<str>, pos: Position) -> Result<()> {
         if let Some(local) = self.find_local(&name) {
             if local.scope == self.scopes.len() {
-                return Err(Error::Redefined(name).into())
+                return error(InnerError::Redefined(name), pos)
             }
         };
         self.create_local(name);
         Ok(())
     }
 
-    fn create_global_checked(&mut self, name: Rc<str>) -> Result<usize> {
+    fn create_global_checked(&mut self, name: Rc<str>, pos: Position) -> Result<usize> {
         if let Some(_) = self.find_global(&name) {
-            return Err(Error::Redefined(name).into())
+            return error(InnerError::Redefined(name).into(), pos)
         }
         Ok(self.create_global(name))
     }
@@ -227,29 +241,29 @@ impl<'c> Compiler<'c> {
         idx
     }
 
-    fn emit_const(&mut self, val: Value) {
+    fn emit_const(&mut self, val: Value, pos: Position) {
         // TODO: find constant if already exists
         self.chunk.constants.push(val);
         let c = self.chunk.constants.len() - 1;
-        self.emit(Instruction::Const(c as u16));
+        self.emit(Instruction::Const(c as u16), pos);
     }
 
     fn can_make_globals(&self) -> bool {
         self.repl && self.parent.is_none() && self.scopes.len() == 0
     }
 
-    fn compile_value(&mut self, val: &Value) {
+    fn compile_value(&mut self, val: &Value, pos: Position) {
         match val {
-            V::Nil => self.emit(I::Nil),
-            V::Bool(b) => if *b { self.emit(I::True) } else { self.emit(I::False) },
+            V::Nil => self.emit(I::Nil, pos),
+            V::Bool(b) => if *b { self.emit(I::True, pos) } else { self.emit(I::False, pos) },
             V::Int(i) => {
                 if let Ok(i) = i16::try_from(*i) {
-                    self.emit(I::Int(i));
+                    self.emit(I::Int(i), pos);
                 } else {
-                    self.emit_const(val.clone());
+                    self.emit_const(val.clone(), pos);
                 }
             },
-            _ => self.emit_const(val.clone()),
+            _ => self.emit_const(val.clone(), pos),
         }
     }
 
@@ -263,152 +277,193 @@ impl<'c> Compiler<'c> {
     }
 
     fn compile_expr(&mut self, expr: &Expr) -> Result<()> {
-        match expr {
-            E::NoOp => self.emit(I::Nil),
+        match &expr.data {
+            E::NoOp => self.emit(I::Nil, expr.pos),
             E::If(cond, ifb, elseb) => {
                 self.compile_expr(cond)?;
-                let jmpidx = self.emit_temp();
+                let jmpidx = self.emit_temp(expr.pos);
                 self.compile_expr(ifb)?;
+                let jmpidx2 = self.emit_temp(expr.pos);
                 self.re_emit(I::JumpFalse(self.cur()), jmpidx);
                 if let Some(elseb) = elseb {
                     self.compile_expr(elseb)?;
                 }
+                self.re_emit(I::Jump(self.cur()), jmpidx2);
             },
             E::Function(name, params, body, varadic) => {
                 let chunk = self.compile_function(name.clone(), params, body)?;
+                let arity = params.len() - if *varadic { 1 } else { 0 };
                 let fun = Value::Function(Rc::new(
                         chunk::Function {
-                            name: name.clone(),
-                            arity: params.len(),
+                            name: name.0.clone(),
+                            arity,
                             fun: InnerFunction::Compiled(chunk.into()),
                             variadic: *varadic
                         }
                 ));
-                self.emit_const(fun);
-                self.emit(I::Dup);
+                self.emit_const(fun, expr.pos);
+                self.emit(I::Dup, expr.pos);
                 if self.can_make_globals() {
-                    let idx = self.create_global_checked(name.clone())?;
-                    self.emit(I::StoreGlobal(idx as u16));
+                    let idx = self.create_global_checked(name.0.clone(), name.1)?;
+                    self.emit(I::StoreGlobal(idx as u16), expr.pos);
                 } else {
-                    self.create_local_checked(name.clone())?;
-                    self.emit(I::CreateLocal);
+                    self.create_local_checked(name.0.clone(), name.1)?;
+                    self.emit(I::CreateLocal, expr.pos);
                 }
             },
             E::Lambda(params, body, varadic) => {
-                let name: Rc<str> = Rc::from("<lambda>");
+                let name: AstName = (Rc::from("<lambda>"), expr.pos);
                 let chunk = self.compile_function(name.clone(), params, body)?;
+                let arity = params.len() - if *varadic { 1 } else { 0 };
                 let fun = Value::Function(Rc::new(
                         chunk::Function {
-                            name: name.clone(),
-                            arity: params.len(),
+                            name: name.0.clone(),
+                            arity,
                             fun: InnerFunction::Compiled(chunk.into()),
                             variadic: *varadic
                         }
                 ));
-                self.emit_const(fun);
+                self.emit_const(fun, expr.pos);
             },
             E::Loop(expr) => {
                 let idx = self.cur();
                 self.loop_top.push((idx as usize, self.scopes.len()));
                 self.compile_expr(expr)?;
-                self.emit(I::Discard(1));
-                self.emit(I::Jump(idx));
+                self.emit(I::Discard(1), expr.pos);
+                self.emit(I::Jump(idx), expr.pos);
                 self.finish_loop();
-                self.emit(I::Nil);
+                self.emit(I::Nil, expr.pos);
+            },
+            E::Try(expr, err, catch) => {
+                let jmpidx = self.emit_temp(expr.pos);
+                self.compile_expr(expr)?;
+                self.emit(I::TryEnd, expr.pos);
+                let jmpidx2 = self.emit_temp(expr.pos);
+                self.re_emit(I::Try(self.cur()), jmpidx);
+                self.begin_scope();
+                self.create_local(err.0.clone());
+                self.emit(I::CreateLocal, err.1);
+                self.compile_expr(catch)?;
+                self.end_scope();
+                self.re_emit(I::Jump(self.cur() as u16), jmpidx2);
             },
             E::While(cond, expr) => {
                 let top = self.cur();
                 self.compile_expr(cond)?;
-                let jmpidx = self.emit_temp();
+                let jmpidx = self.emit_temp(expr.pos);
                 self.loop_top.push((top as usize, self.scopes.len()));
                 self.compile_expr(expr)?;
-                self.emit(I::Discard(1));
-                self.emit(I::Jump(top));
+                self.emit(I::Discard(1), expr.pos);
+                self.emit(I::Jump(top), expr.pos);
                 self.re_emit(I::JumpFalse(self.cur()), jmpidx);
                 self.finish_loop();
-                self.emit(I::Nil);
+                self.emit(I::Nil, expr.pos);
             },
             E::DoWhile(expr, cond) => {
                 let top = self.cur();
                 self.loop_top.push((top as usize, self.scopes.len()));
                 self.compile_expr(expr)?;
-                self.emit(I::Discard(1));
+                self.emit(I::Discard(1), expr.pos);
                 self.compile_expr(cond)?;
-                self.emit(I::JumpTrue(top));
+                self.emit(I::JumpTrue(top), expr.pos);
                 self.finish_loop();
-                self.emit(I::Nil);
+                self.emit(I::Nil, expr.pos);
             },
+            E::For(name, cond, expr) => {
+                self.compile_expr(cond)?;
+                self.emit(I::IterCreate, cond.pos);
+                let top = self.cur();
+                self.emit(I::IterNext, cond.pos);
+                self.emit(I::Dup, expr.pos);
+                let jumpidx = self.emit_temp(expr.pos);
+                self.loop_top.push((top as usize, self.scopes.len()));
+                self.begin_scope();
+                self.create_local(name.0.clone());
+                self.emit(I::CreateLocal, name.1);
+                self.compile_expr(expr)?;
+                self.emit(I::Discard(1), expr.pos);
+                self.end_scope();
+                self.emit(I::Jump(top), expr.pos);
+                self.re_emit(I::JumpNil(self.cur()), jumpidx);
+                self.finish_loop();
+                self.emit(I::Discard(2), expr.pos);
+                self.emit(I::Nil, expr.pos);
+            }
             E::Block(block) => {
+                if block.len() == 0 {
+                    self.emit(I::Nil, expr.pos);
+                    return Ok(());
+                }
                 self.begin_scope();
                 for (i, expr) in block.iter().enumerate() {
                     self.compile_expr(expr)?;
                     if i + 1 != block.len() {
-                        self.emit(I::Discard(1));
+                        self.emit(I::Discard(1), expr.pos);
                     }
                 }
                 self.end_scope();
             },
             E::Let(name, expr) => {
                 self.compile_expr(expr)?;
-                self.emit(I::Dup);
+                self.emit(I::Dup, expr.pos);
                 if self.can_make_globals() {
-                    let global = self.create_global_checked(name.clone())?;
-                    self.emit(I::StoreGlobal(global as u16));
+                    let global = self.create_global_checked(name.0.clone(), name.1)?;
+                    self.emit(I::StoreGlobal(global as u16), expr.pos);
                 } else {
-                    self.create_local_checked(name.clone())?;
-                    self.emit(I::CreateLocal);
+                    self.create_local_checked(name.0.clone(), name.1)?;
+                    self.emit(I::CreateLocal, expr.pos);
                 }
             },
             E::Continue => {
                 let top = self.loop_top.pop();
                 if let Some((top, scope)) = top {
                     self.collapse_scopes(scope);
-                    self.emit(I::Jump(top as u16));
+                    self.emit(I::Jump(top as u16), expr.pos);
                 } else {
-                    return Err(Error::InvContinue.into())
+                    return error(InnerError::InvContinue, expr.pos)
                 }
             },
             E::Break => {
                 let top = self.loop_top.pop();
                 if let Some((_, scope)) = top {
                     self.collapse_scopes(scope);
-                    let tmpidx = self.emit_temp();
+                    let tmpidx = self.emit_temp(expr.pos);
                     self.loop_bot.push(tmpidx);
                 } else {
-                    return Err(Error::InvBreak.into())
+                    return error(InnerError::InvBreak, expr.pos)
                 }
             },
             E::Return(expr) => {
                 self.compile_expr(expr)?;
-                self.emit(I::Return);
+                self.emit(I::Return, expr.pos);
             },
-            E::Literal(val) => self.compile_value(val),
+            E::Literal(val) => self.compile_value(val, expr.pos),
             E::Ident(name) => {
                 if name.as_ref() == "_" {
-                    self.emit(I::Nil);
+                    self.emit(I::Nil, expr.pos);
                 } else if let Some(local) = self.find_local(name) {
-                    self.emit(I::LoadLocal(local.idx as u16));
+                    self.emit(I::LoadLocal(local.idx as u16), expr.pos);
                 } else if let Some(global) = self.find_global(name) {
-                    self.emit(I::LoadGlobal(global as u16));
+                    self.emit(I::LoadGlobal(global as u16), expr.pos);
                 } else {
-                    return Err(self::Error::Undefined(name.clone()).into())
+                    return error(InnerError::Undefined(name.clone()), expr.pos)
                 };
             },
             E::Assign(lhs, rhs) => {
                 self.compile_expr(rhs)?;
-                self.emit(I::Dup);
-                match lhs.as_ref() {
+                self.emit(I::Dup, rhs.pos);
+                match &lhs.data {
                     E::Ident(name) if name.as_ref() != "_" => {
                         if let Some(local) = self.find_local(&name) {
-                            self.emit(I::StoreLocal(local.idx as u16));
+                            self.emit(I::StoreLocal(local.idx as u16), lhs.pos);
                         } else if let Some(global) = self.find_global(&name) {
-                            self.emit(I::StoreGlobal(global as u16));
+                            self.emit(I::StoreGlobal(global as u16), lhs.pos);
                         } else if self.can_make_globals() {
-                            let global = self.create_global_checked(name.clone())?;
-                            self.emit(I::StoreGlobal(global as u16));
+                            let global = self.create_global_checked(name.clone(), lhs.pos)?;
+                            self.emit(I::StoreGlobal(global as u16), lhs.pos);
                         } else {
-                            self.create_local_checked(name.clone())?;
-                            self.emit(I::CreateLocal);
+                            self.create_local_checked(name.clone(), lhs.pos)?;
+                            self.emit(I::CreateLocal, lhs.pos);
                         }
                     },
                     E::Index(expr, params) => {
@@ -416,89 +471,94 @@ impl<'c> Compiler<'c> {
                         for param in params {
                             self.compile_expr(param)?;
                         }
-                        self.emit(I::StoreIndex(params.len() as u8));
+                        self.emit(I::StoreIndex(params.len() as u8), expr.pos);
                     },
                     E::FieldAccess(expr, ident) => {
                         self.compile_expr(expr)?;
-                        let name = self.get_name(ident.clone());
-                        self.emit(I::StoreField(name as u16));
+                        let name = self.get_name(ident.0.clone());
+                        self.emit(I::StoreField(name as u16), expr.pos);
                     }
-                    _ => return Err(self::Error::InvAssign(*lhs.clone()).into())
+                    _ => return error(InnerError::InvAssign(*lhs.clone()), lhs.pos)
                 }
             }
             E::UnaryOp(expr, op) => {
                 self.compile_expr(expr)?;
-                self.emit(I::UnaryOp(*op));
+                self.emit(I::UnaryOp(*op), expr.pos);
             },
             E::BinaryOp(lhs, rhs, op) => {
                 self.compile_expr(lhs)?;
                 self.compile_expr(rhs)?;
-                self.emit(I::BinaryOp(*op));
+                self.emit(I::BinaryOp(*op), lhs.pos);
             },
             E::Index(expr, params) => {
                 self.compile_expr(expr)?;
                 for param in params {
                     self.compile_expr(param)?;
                 }
-                self.emit(I::Index(params.len() as u8))
+                self.emit(I::Index(params.len() as u8), expr.pos)
             },
             E::FnCall(fun, params) => {
                 for expr in params {
                     self.compile_expr(expr)?;
                 }
                 self.compile_expr(fun)?;
-                self.emit(I::Call(params.len() as u8));
+                self.emit(I::Call(params.len() as u8), expr.pos);
             },
             E::FieldAccess(expr, field) => {
                 self.compile_expr(expr)?;
-                let idx = self.get_name(field.clone());
-                self.emit(I::Field(idx as u16))
+                let idx = self.get_name(field.0.clone());
+                self.emit(I::Field(idx as u16), expr.pos)
             }
             E::List(list) => {
                 for expr in list {
                     self.compile_expr(expr)?;
                 }
-                self.emit(I::NewList(list.len() as u16));
+                self.emit(I::NewList(list.len() as u16), expr.pos);
             },
             E::Matrix(mat) => {
                 for expr in &mat.2 {
                     self.compile_expr(expr)?;
                 }
-                self.emit(I::NewMatrix(mat.2.len() as u16, mat.0 as u8));
+                self.emit(I::NewMatrix(mat.2.len() as u16, mat.0 as u8), expr.pos);
             },
             E::Table(table) => {
                 for (key, value) in table {
                     self.compile_expr(key)?;
                     self.compile_expr(value)?;
                 }
-                self.emit(I::NewTable(table.len() as u16));
+                self.emit(I::NewTable(table.len() as u16), expr.pos);
             },
             E::And(lhs, rhs) => {
                 self.compile_expr(lhs)?;
-                self.emit(I::Dup);
-                let jmpidx = self.emit_temp();
+                self.emit(I::Dup, lhs.pos);
+                let jmpidx = self.emit_temp(lhs.pos);
                 self.compile_expr(rhs)?;
                 self.re_emit(I::JumpFalse(self.cur()), jmpidx);
             },
             E::Or(lhs, rhs) => {
                 self.compile_expr(lhs)?;
-                self.emit(I::Dup);
-                let jmpidx = self.emit_temp();
+                self.emit(I::Dup, lhs.pos);
+                let jmpidx = self.emit_temp(lhs.pos);
                 self.compile_expr(rhs)?;
                 self.re_emit(I::JumpTrue(self.cur()), jmpidx);
             },
+            E::Pipeline(lhs, rhs) => {
+                self.compile_expr(lhs)?;
+                self.compile_expr(rhs)?;
+                self.emit(I::Call(1), expr.pos);
+            }
         };
         Ok(())
     }
 
-    fn compile_function(&mut self, name: Rc<str>, params: &Vec<Rc<str>>, body: &Box<Expr>) -> Result<Chunk> {
-        let mut compiler = self.child(name);
-        for name in params {
+    fn compile_function(&mut self, name: AstName, params: &Vec<AstName>, body: &Box<Expr>) -> Result<Chunk> {
+        let mut compiler = self.child(name.0);
+        for (name, pos) in params {
             compiler.create_local(name.clone());
-            compiler.emit(I::CreateLocal);
+            compiler.emit(I::CreateLocal, *pos);
         }
         compiler.compile_expr(body)?;
-        compiler.finish()?;
+        compiler.finish(name.1)?;
         Ok(compiler.chunk)
     }
 
@@ -506,15 +566,16 @@ impl<'c> Compiler<'c> {
         self.chunk.code.len() as u16
     }
 
-    fn emit_temp(&mut self) -> usize {
+    fn emit_temp(&mut self, pos: Position) -> usize {
         let idx = self.chunk.code.len();
-        self.emit(Instruction::NoOp);
+        self.emit(Instruction::NoOp, pos);
         idx
     }
 
-    fn emit(&mut self, ins: Instruction) {
+    fn emit(&mut self, ins: Instruction, pos: Position) {
         //println!("{}: {ins}", self.name);
         self.chunk.code.push(ins);
+        self.chunk.pos.push(pos);
     }
 
     fn re_emit(&mut self, ins: Instruction, idx: usize) {
@@ -522,12 +583,20 @@ impl<'c> Compiler<'c> {
         self.chunk.code[idx] = ins;
     }
 
-    fn finish(&mut self) -> Result<()> {
+    fn last_pos(&self) -> Position {
+        if let Some(pos) = self.chunk.pos.last() {
+            *pos
+        } else {
+            Position::default()
+        }
+    }
+
+    fn finish(&mut self, pos: Position) -> Result<()> {
         let ins = match self.chunk.code.last() {
             Some(ins) => ins.clone(),
             None => {
-                self.emit(I::Nil);
-                self.emit(I::Return);
+                self.emit(I::Nil, pos);
+                self.emit(I::Return, pos);
                 if self.debug {
                     println!("{}\n{}", self.name, self.chunk);
                 }
@@ -537,12 +606,12 @@ impl<'c> Compiler<'c> {
         match ins {
             I::Return => {},
             _ => {
-                self.emit(I::Return);
+                self.emit(I::Return, pos);
             }
         };
 
         if self.loop_bot.len() > 0 {
-            return Err(Error::InvBreak.into())
+            return error(InnerError::InvBreak, pos)
         }
 
         if self.debug {
@@ -555,12 +624,12 @@ impl<'c> Compiler<'c> {
         &mut self,
         body: &Expr,
     ) -> Result<Rc<Function>> {
-        if let Expr::Block(_) = body {
+        if let ExprData::Block(_) = &body.data {
             self.root_is_block = true;
         }
         self.chunk = Chunk::new();
         self.compile_expr(body)?;
-        self.finish()?;
+        self.finish(self.last_pos())?;
         let fun = Function { name: self.name.clone(), fun: InnerFunction::Compiled(self.chunk.clone().into()), arity: 0, variadic: false };
         Ok(Rc::new(fun))
     }
diff --git a/matrix/src/gc.rs b/matrix/src/gc.rs
index 0c60849..8fba633 100644
--- a/matrix/src/gc.rs
+++ b/matrix/src/gc.rs
@@ -31,6 +31,12 @@ impl <T: Clone> Gc<T> {
         }
     }
 
+    pub fn into_inner(self) -> T {
+        unsafe {
+            self.ptr.as_ref().data.clone()
+        }
+    }
+
     fn data(&self) -> T {
         unsafe {
             self.ptr.as_ref().data.clone()
diff --git a/matrix/src/lex.rs b/matrix/src/lex.rs
index 16032f9..8a07234 100644
--- a/matrix/src/lex.rs
+++ b/matrix/src/lex.rs
@@ -31,7 +31,7 @@ impl From<RegexToken> for Regex {
 }
 
 #[derive(Debug, PartialEq)]
-pub enum Token {
+pub enum TokenData {
     //syntax
     LeftParen,
     RightParen,
@@ -46,9 +46,11 @@ pub enum Token {
     ThinArrow,
     Comma,
     Range,
+    RangeEq,
     Colon,
     Backslash,
     Varadic,
+    Pipe,
 
     // math
     Regex(RegexToken),
@@ -113,11 +115,24 @@ pub enum Token {
     Do,
     Loop,
     Return,
+    For,
+    In,
+    Try,
+    Catch,
 
     // eof
     Eof,
 }
 
+#[derive(Debug, PartialEq)]
+pub struct Token {
+    pub data: TokenData,
+    pub pos: Position,
+    pub str: String,
+    pub bidx: usize,
+    pub blen: usize,
+}
+
 #[derive(Debug)]
 pub enum Error {
     UnexpectedCharacter(char),
@@ -148,10 +163,24 @@ impl std::fmt::Display for Error {
 
 impl std::error::Error for Error {}
 
+#[derive(Debug, Clone, PartialEq, Eq, Copy)]
+pub struct Position {
+    pub row: usize,
+    pub col: usize,
+}
+
+impl Default for Position {
+    fn default() -> Self {
+        Self { row: 1, col: 1 }
+    }
+}
+
 pub struct Lexer {
     pub index: usize,
     len: usize,
     data: Vec<char>,
+    pos: Position,
+    byte_len: usize,
 }
 
 trait IsIdent {
@@ -177,7 +206,13 @@ impl<T: Into<String>> From<T> for Lexer {
 impl Lexer {
     pub fn new<T: Into<String>>(input: T) -> Self {
         let data: Vec<char> = input.into().chars().collect();
-        Self { index: 0, len: data.len(), data }
+        Self {
+            index: 0,
+            len: data.len(),
+            data,
+            pos: Position::default(),
+            byte_len: 0
+        }
     }
 
     fn peek(&self) -> char {
@@ -190,6 +225,14 @@ impl Lexer {
     fn next(&mut self) -> char {
         let c = self.peek();
         self.index += 1;
+        self.byte_len += c.len_utf8();
+
+        self.pos.col += 1;
+        if c == '\n' {
+            self.pos.col = 1;
+            self.pos.row += 1;
+        }
+
         c
     }
 
@@ -274,14 +317,14 @@ impl Lexer {
         Ok(buf.into())
     }
 
-    fn lex_ident(&mut self, initial: char) -> Result<Token> {
-        use Error::*;
-        use Token::*;
+    fn lex_ident(&mut self, initial: char) -> Result<TokenData> {
+        use Error as E;
+        use TokenData as T;
 
         let mut buf = std::string::String::new();
 
         if !initial.is_initial_ident() {
-            return Err(UnexpectedCharacter(initial).into())
+            return Err(E::UnexpectedCharacter(initial).into())
         }
 
         buf.push(initial);
@@ -295,29 +338,33 @@ impl Lexer {
         }
 
         Ok(match buf.as_str() {
-            "if" => If,
-            "else" => Else,
-            "while" => While,
-            "let" => Let,
-            "fn" | "function" => Function,
-            "true" => True,
-            "false" => False,
-            "nil" => Nil,
-            "continue" => Continue,
-            "break" => Break,
-            "do" => Do,
-            "loop" => Loop,
-            "and" => And,
-            "or" => Or,
-            "not" => Not,
-            "return" => Return,
-            _ => Ident(buf.into())
+            "if" => T::If,
+            "else" => T::Else,
+            "while" => T::While,
+            "let" => T::Let,
+            "fn" | "function" => T::Function,
+            "true" => T::True,
+            "false" => T::False,
+            "nil" => T::Nil,
+            "continue" => T::Continue,
+            "break" => T::Break,
+            "do" => T::Do,
+            "loop" => T::Loop,
+            "and" => T::And,
+            "or" => T::Or,
+            "not" => T::Not,
+            "return" => T::Return,
+            "for" => T::For,
+            "in" => T::In,
+            "try" => T::Try,
+            "catch" => T::Catch,
+            _ => T::Ident(buf.into())
         })
     }
 
-    fn lex_radix(&mut self, radix: i64, radix_char: char) -> Result<Token> {
-        use Token::*;
-        use Error::*;
+    fn lex_radix(&mut self, radix: i64, radix_char: char) -> Result<TokenData> {
+        use TokenData as T;
+        use Error as E;
 
         let mut n = 0i64;
         let mut char_found = false;
@@ -328,21 +375,21 @@ impl Lexer {
                 n = n * radix + (i as i64);
                 char_found = true;
             } else if self.peek().is_ident() {
-                return Err(InvalidDigit(self.peek()).into())
+                return Err(E::InvalidDigit(self.peek()).into())
             } else {
                 break;
             }
         }
 
         if char_found {
-            Ok(Int(n))
+            Ok(T::Int(n))
         } else {
-            Err(InvalidNumber(format!("0{radix_char}")).into())
+            Err(E::InvalidNumber(format!("0{radix_char}")).into())
         }
     }
 
-    fn lex_number(&mut self, initial: char) -> Result<Token> {
-        use Error::*;
+    fn lex_number(&mut self, initial: char) -> Result<TokenData> {
+        use Error as E;
 
         if initial == '0' {
             match self.peek() {
@@ -361,6 +408,10 @@ impl Lexer {
         let mut buf = String::new();
         buf.push(initial);
 
+        let mut pos = self.pos;
+        let mut idx = self.index;
+        let mut bidx = self.byte_len;
+
         if initial != '.' {
             loop {
                 if !self.peek().is_ascii_digit() { break; }
@@ -368,24 +419,37 @@ impl Lexer {
             }
 
             if self.peek() == '.' {
+                pos = self.pos;
+                idx = self.index;
+                bidx = self.byte_len;
                 buf.push(self.next());
             }
         }
 
-        loop {
-            if !self.peek().is_ascii_digit() { break; }
-            buf.push(self.next());
-        }
+        let last: char = buf.chars().last().unwrap();
+        let is_range = initial != '.' && last == '.' && self.peek() == '.';
 
-        if self.peek() == 'e' || self.peek() == 'E' {
-            buf.push(self.next());
-            if self.peek() == '+' || self.peek() == '-' {
+        if is_range {
+            self.pos = pos;
+            self.index = idx;
+            self.byte_len = bidx;
+            buf.pop();
+        } else {
+            loop {
+                if !self.peek().is_ascii_digit() { break; }
                 buf.push(self.next());
             }
 
-            loop {
-                if !self.peek().is_ascii_digit() { break; }
+            if self.peek() == 'e' || self.peek() == 'E' {
                 buf.push(self.next());
+                if self.peek() == '+' || self.peek() == '-' {
+                    buf.push(self.next());
+                }
+
+                loop {
+                    if !self.peek().is_ascii_digit() { break; }
+                    buf.push(self.next());
+                }
             }
         }
 
@@ -394,87 +458,103 @@ impl Lexer {
             self.next();
         }
 
-        if self.peek().is_ident() || self.peek() == '.' {
-            return Err(UnexpectedCharacter(self.peek()).into())
+        if self.peek().is_ident() {
+            return Err(E::UnexpectedCharacter(self.peek()).into())
         }
 
         if let Ok(int) = buf.parse::<i64>() {
-            use Token::*;
+            use TokenData as T;
             if complex {
-                return Ok(Complex(int as f64))
+                return Ok(T::Complex(int as f64))
             }
-            return Ok(Int(int))
+            return Ok(T::Int(int))
         }
 
         if let Ok(float) = buf.parse::<f64>() {
-            use Token::*;
+            use TokenData as T;
             if complex {
-                return Ok(Complex(float))
+                return Ok(T::Complex(float))
             }
-            return Ok(Float(float))
+            return Ok(T::Float(float))
         }
 
-        Err(Error::InvalidNumber(buf).into())
+        Err(E::InvalidNumber(buf).into())
     }
 
     fn peek_token_impl(&mut self, ignore_newlines: bool) -> Result<Token> {
         let idx = self.index;
+        let pos = self.pos;
+        let bidx = self.byte_len;
         let token = self.next_token_impl(ignore_newlines);
         self.index = idx;
+        self.pos = pos;
+        self.byte_len = bidx;
         token
     }
 
     fn next_token_impl(&mut self, ignore_newlines: bool) -> Result<Token> {
-        use Token::*;
-        use Error::*;
+        use TokenData as T;
+        use Error as E;
 
         self.skip_whitespace(ignore_newlines);
+
+        let str_start = self.index;
+        let byte_start = self.byte_len;
+
+        let pos = self.pos;
         let char = self.next();
         let next = self.peek();
 
         if char == '\0' {
-            return Ok(if ignore_newlines { Eof } else { SemiColon });
+            let data = if ignore_newlines { T::Eof } else { T::SemiColon };
+            return Ok(Token {
+                data,
+                pos,
+                str: String::new(),
+                bidx: byte_start,
+                blen: 0,
+            })
         }
 
-        Ok(match char {
-            '\n' => SemiColon,
-            '(' => LeftParen,
-            ')' => RightParen,
-            '[' => LeftBrack,
-            ']' => RightBrack,
-            '{' => LeftBrace,
-            '}' => RightBrace,
-            ':' => Colon,
-            '\\' => Backslash,
-            ';' => SemiColon,
+        let data = match char {
+            '\n' => T::SemiColon,
+            '(' => T::LeftParen,
+            ')' => T::RightParen,
+            '[' => T::LeftBrack,
+            ']' => T::RightBrack,
+            '{' => T::LeftBrace,
+            '}' => T::RightBrace,
+            ':' => T::Colon,
+            '\\' => T::Backslash,
+            ';' => T::SemiColon,
             '+' => {
                 match next {
                     '=' => {
                         self.next();
-                        AssignAdd
+                        T::AssignAdd
                     }
-                    _ => Add
+                    _ => T::Add
                 }
             },
             '/' => {
                 match next {
                     '=' => {
                         self.next();
-                        AssignDivide
+                        T::AssignDivide
                     }
-                    _ => Divide
+                    _ => T::Divide
                 }
             },
             '%' => {
                 match next {
                     '=' => {
                         self.next();
-                        AssignModulo
+                        T::AssignModulo
                     }
-                    _ => Modulo
+                    _ => T::Modulo
                 }
             },
-            ',' => Comma,
+            ',' => T::Comma,
             '*' => {
                 match next {
                     '*' => {
@@ -482,25 +562,25 @@ impl Lexer {
                         match self.peek() {
                             '=' => {
                                 self.next();
-                                AssignPower
+                                T::AssignPower
                             },
-                            _ => Power
+                            _ => T::Power
                         }
                     },
                     '=' => {
                         self.next();
-                        AssignMultiply
+                        T::AssignMultiply
                     }
-                    _ => Multiply
+                    _ => T::Multiply
                 }
             },
             '!' => {
                 match next {
                     '=' => {
                         self.next();
-                        NotEqual
+                        T::NotEqual
                     }
-                    _ => Not
+                    _ => T::Not
                 }
             }
             '&' => {
@@ -510,16 +590,16 @@ impl Lexer {
                         match self.peek() {
                             '=' => {
                                 self.next();
-                                AssignAnd
+                                T::AssignAnd
                             },
-                            _ => And
+                            _ => T::And
                         }
                     },
                     '=' => {
                         self.next();
-                        AssignBitwiseAnd
+                        T::AssignBitwiseAnd
                     },
-                    _ => BitwiseAnd
+                    _ => T::BitwiseAnd
                 }
             },
             '|' => {
@@ -529,42 +609,46 @@ impl Lexer {
                         match self.peek() {
                             '=' => {
                                 self.next();
-                                AssignOr
+                                T::AssignOr
                             },
-                            _ => Or
+                            _ => T::Or
                         }
                     },
                     '=' => {
                         self.next();
-                        AssignBitwiseOr
+                        T::AssignBitwiseOr
+                    },
+                    '>' => {
+                        self.next();
+                        T::Pipe
                     },
-                    _ => BitwiseOr
+                    _ => T::BitwiseOr
                 }
             },
             '-' => {
                 match next {
                     '>' => {
                         self.next();
-                        ThinArrow
+                        T::ThinArrow
                     },
                     '=' => {
                         self.next();
-                        AssignSubtract
+                        T::AssignSubtract
                     },
-                    _ => Subtract
+                    _ => T::Subtract
                 }
             },
             '=' => {
                 match next {
                     '>' => {
                         self.next();
-                        Arrow
+                        T::Arrow
                     }
                     '=' => {
                         self.next();
-                        Equal
+                        T::Equal
                     }
-                    _ => Assign
+                    _ => T::Assign
                 }
             },
             '>' => {
@@ -574,16 +658,16 @@ impl Lexer {
                         match self.peek() {
                             '=' => {
                                 self.next();
-                                AssignBitwiseShiftRight
+                                T::AssignBitwiseShiftRight
                             },
-                            _ => BitwiseShiftRight
+                            _ => T::BitwiseShiftRight
                         }
                     }
                     '=' => {
                         self.next();
-                        GreaterEqual
+                        T::GreaterEqual
                     }
-                    _ => GreaterThan
+                    _ => T::GreaterThan
                 }
             },
             '<' => {
@@ -593,35 +677,35 @@ impl Lexer {
                         match self.peek() {
                             '=' => {
                                 self.next();
-                                AssignBitwiseShiftLeft
+                                T::AssignBitwiseShiftLeft
                             },
-                            _ => BitwiseShiftLeft
+                            _ => T::BitwiseShiftLeft
                         }
                     }
                     '=' => {
                         self.next();
-                        LessEqual
+                        T::LessEqual
                     }
-                    _ => LessThan
+                    _ => T::LessThan
                 }
             },
             '^' => {
                 match next {
                     '=' => {
                         self.next();
-                        AssignBitwiseXor
+                        T::AssignBitwiseXor
                     },
-                    _ => BitwiseXor
+                    _ => T::BitwiseXor
                 }
             }
-            '\'' | '\"' => String(self.lex_string(char)?),
+            '\'' | '\"' => T::String(self.lex_string(char)?),
             'r' => {
                 match next {
                     '\'' | '\"' => {
                         self.next();
-                        Regex(regex::Regex::new(&self.lex_string(next)?)
+                        T::Regex(regex::Regex::new(&self.lex_string(next)?)
                               .map(|e| e.into())
-                              .map_err(|e| InvalidRegex(e.into()))?)
+                              .map_err(|e| E::InvalidRegex(e.into()))?)
                     }
                     _ => {
                         self.lex_ident(char)?
@@ -634,14 +718,18 @@ impl Lexer {
                     match self.peek() {
                         '.' => {
                             self.next();
-                            Varadic
+                            T::Varadic
                         },
-                        _ => Range
+                        '=' => {
+                            self.next();
+                            T::RangeEq
+                        },
+                        _ => T::Range
                     }
                 } else if next.is_digit(10) {
                     self.lex_number(char)?
                 } else {
-                    Access
+                    T::Access
                 }
             },
             _ => {
@@ -651,6 +739,18 @@ impl Lexer {
                     self.lex_ident(char)?
                 }
             },
+        };
+
+        let str_end = self.index;
+        let byte_end = self.byte_len;
+        let str = self.data[str_start..str_end].to_owned().into_iter().collect();
+
+        Ok(Token {
+            data,
+            pos,
+            str,
+            bidx: byte_start,
+            blen: byte_end - byte_start
         })
     }
 
diff --git a/matrix/src/lib.rs b/matrix/src/lib.rs
index fbc1aac..5a9be9f 100644
--- a/matrix/src/lib.rs
+++ b/matrix/src/lib.rs
@@ -1,4 +1,4 @@
-use std::fmt::Display;
+use std::{fmt::Display, rc::Rc};
 
 pub mod compiler;
 pub mod value;
@@ -9,8 +9,11 @@ pub mod parse;
 pub mod chunk;
 pub mod ast;
 
-#[derive(Debug)]
-pub struct Error(Box<ErrorInner>);
+pub use ::num_complex::Complex64 as Complex64;
+pub use ::num_rational::Rational64 as Rational64;
+
+#[derive(Debug, Clone)]
+pub struct Error(Rc<ErrorInner>);
 
 impl std::error::Error for Error {}
 
@@ -22,6 +25,8 @@ enum ErrorInner {
     Compile(compiler::Error),
     Runtime(vm::Error),
     External(anyhow::Error),
+    Traced(Box<Error>, String),
+    Any(String),
 }
 
 impl Display for crate::Error {
@@ -34,6 +39,8 @@ impl Display for crate::Error {
             Compile(err) => write!(f, "{err}"),
             Runtime(err) => write!(f, "{err}"),
             External(err) => write!(f, "{err}"),
+            Traced(err, trace) => write!(f, "{err}\n{trace}"),
+            Any(err) => write!(f, "{err}"),
         }
     }
 }
@@ -42,7 +49,7 @@ macro_rules! from_error {
     ($struct:ty, $tuple:tt) => {
         impl From<$struct> for crate::Error {
             fn from(value: $struct) -> Self {
-                crate::Error(Box::new(ErrorInner::$tuple(value)))
+                crate::Error(Rc::new(ErrorInner::$tuple(value)))
             }
         }
     };
@@ -54,5 +61,62 @@ from_error!(value::Error, Value);
 from_error!(compiler::Error, Compile);
 from_error!(vm::Error, Runtime);
 from_error!(anyhow::Error, External);
+from_error!(String, Any);
+
+impl From<(Error, String)> for Error {
+    fn from(value: (Error, String)) -> Self {
+        Self(Rc::new(ErrorInner::Traced(Box::new(value.0), value.1)))
+    }
+}
+
+#[macro_export]
+macro_rules! iter {
+    ($fn:expr) => {
+        $crate::value::Value::Iter(
+            ::std::rc::Rc::new(
+                $crate::chunk::Function {
+                    name: ::std::rc::Rc::from("<iterator>"),
+                    arity: 0,
+                    variadic: false,
+                    fun: $crate::chunk::InnerFunction::Native(
+                        ::std::rc::Rc::new($fn
+        ))}))
+    };
+}
+
+#[macro_export]
+macro_rules! native {
+    ($name:expr, $arity:expr, $varadic:expr, $fn:expr) => {
+        $crate::value::Value::Function(
+            ::std::rc::Rc::new( $crate::chunk::Function {
+                name: std::rc::Rc::from($name),
+                arity: $arity,
+                variadic: $varadic,
+                fun: $crate::chunk::InnerFunction::Native(
+                    ::std::rc::Rc::new($fn)
+                )
+            })
+        )
+    }
+}
+
+#[macro_export]
+macro_rules! unpack_args {
+    ($e:expr) => {
+        $e.try_into().expect("bypassed arity check")
+    };
+}
+
+#[macro_export]
+macro_rules! unpack_varargs {
+    ($e:expr) => {{
+        let mut args = $e;
+        let $crate::value::Value::List(varargs) = args.pop().expect("bypassed arity check") else {
+            panic!("bypassed arity check")
+        };
+        let varargs = varargs.into_inner();
+        (args.try_into().expect("bypassed arity check"), varargs)
+    }};
+}
 
 pub type Result<T> = std::result::Result<T, crate::Error>;
diff --git a/matrix/src/parse.rs b/matrix/src/parse.rs
index f3814fb..d967130 100644
--- a/matrix/src/parse.rs
+++ b/matrix/src/parse.rs
@@ -1,11 +1,10 @@
 use std::{fmt::Display, rc::Rc};
 use num_complex::Complex64;
-
-use crate::{lex::{Lexer, self, Token}, ast::{Expr, BinaryOp, UnaryOp, optimize}, value::{Value, self}, Result};
+use crate::{lex::{Lexer, self, Token, TokenData, Position}, ast::{Expr, BinaryOp, UnaryOp, optimize, ExprData, AstName}, value::{Value, self}, Result};
 
 use Value as V;
-use Expr as E;
-use Token as T;
+use ExprData as E;
+use TokenData as T;
 
 pub struct ParserBuilder {
     optimize: bool
@@ -38,8 +37,7 @@ pub struct Parser {
 pub enum Error {
     LexerError(crate::lex::Error),
     UnexpectedToken(Token),
-    ExpectedToken(Token),
-    ExpectedTokenName(&'static str),
+    ExpectedToken(TokenData, Position),
     MatrixInvDomain(usize, usize, usize),
     NotAssignable(Expr),
     ValueError(value::Error),
@@ -50,9 +48,8 @@ impl Display for Error {
         use Error::*;
         match self {
             LexerError(err) => write!(f, "{err}"),
-            UnexpectedToken(tok) => write!(f, "Unexpected token: '{tok:?}'"),
-            ExpectedToken(tok) => write!(f, "Expected token: '{tok:?}'"),
-            ExpectedTokenName(name) => write!(f, "Expected {name} token"),
+            UnexpectedToken(tok) => write!(f, "Unexpected token: '{:?}' at {}:{}", tok.data, tok.pos.row, tok.pos.col),
+            ExpectedToken(tok, pos) => write!(f, "Expected token: '{tok:?}' at {}:{}", pos.row, pos.col),
             MatrixInvDomain(row, should, was) => write!(f, "In row {row} of matrix, domain was expected to be {should} but was given {was}"),
             NotAssignable(expr) => write!(f, "{expr:?} is not assignable"),
             ValueError(err) => write!(f, "{err}"),
@@ -71,13 +68,14 @@ impl std::error::Error for Error {}
 macro_rules! expr_parser {
     ($parser:ident, $pattern:pat, $fn:ident) => {{
         let mut expr = $parser.$fn()?;
+        let pos = expr.pos;
         loop {
             let tok = $parser.lexer.peek_token_nl()?;
-            match tok {
+            match tok.data {
                 $pattern => {
                     $parser.lexer.next_token_nl()?;
                     let temp = $parser.$fn()?;
-                    expr = E::BinaryOp(Box::new(expr), Box::new(temp), BinaryOp::from(tok))
+                    expr = (E::BinaryOp(Box::new(expr), Box::new(temp), BinaryOp::from(tok.data)), pos).into()
                 }
                 _ => break
             }
@@ -90,10 +88,11 @@ macro_rules! expr_parser_reverse {
     ($parser:ident, $pattern:pat, $fn:ident, $cur:ident) => {{
         let expr = $parser.$fn()?;
         let tok = $parser.lexer.peek_token_nl()?;
-        Ok(match tok {
+        let pos = tok.pos;
+        Ok(match tok.data {
             $pattern => {
                 $parser.lexer.next_token_nl()?;
-                E::BinaryOp(Box::new(expr), Box::new($parser.$cur()?), BinaryOp::from(tok))
+                (E::BinaryOp(Box::new(expr), Box::new($parser.$cur()?), BinaryOp::from(tok.data)), pos).into()
             }
             _ => expr
         })
@@ -102,19 +101,19 @@ macro_rules! expr_parser_reverse {
 
 impl Parser {
 
-    fn force_token(&mut self, tok: Token) -> Result<Token> {
+    fn force_token(&mut self, tok: TokenData) -> Result<TokenData> {
         let next = self.lexer.next_token()?;
-        if next != tok {
-            Err(Error::ExpectedToken(tok).into())
+        if next.data != tok {
+            Err(Error::ExpectedToken(tok, next.pos).into())
         } else {
             Ok(tok)
         }
     }
 
-    fn force_token_nl(&mut self, tok: Token) -> Result<Token> {
+    fn force_token_nl(&mut self, tok: TokenData) -> Result<TokenData> {
         let next = self.lexer.next_token_nl()?;
-        if next != tok {
-            Err(Error::ExpectedToken(tok).into())
+        if next.data != tok {
+            Err(Error::ExpectedToken(tok, next.pos).into())
         } else {
             Ok(tok)
         }
@@ -124,7 +123,7 @@ impl Parser {
         self.force_token(T::LeftParen)?;
         let mut params = Vec::new();
         loop {
-            let expr = match self.lexer.peek_token()? {
+            let expr = match self.lexer.peek_token()?.data {
                 T::RightParen => {
                     self.lexer.next_token()?;
                     break
@@ -133,7 +132,7 @@ impl Parser {
             };
             params.push(expr);
             let next = self.lexer.next_token()?;
-            match next {
+            match next.data {
                 T::Comma => continue,
                 T::RightParen => break,
                 _ => return Err(Error::UnexpectedToken(next).into())
@@ -146,7 +145,7 @@ impl Parser {
         self.force_token(T::LeftBrack)?;
         let mut indicies = Vec::new();
         loop {
-            let expr = match self.lexer.peek_token()? {
+            let expr = match self.lexer.peek_token()?.data {
                 T::RightBrack => {
                     self.lexer.next_token()?;
                     break
@@ -155,7 +154,7 @@ impl Parser {
             };
             indicies.push(expr);
             let next = self.lexer.next_token()?;
-            match next {
+            match next.data {
                 T::SemiColon => continue,
                 T::RightBrack => break,
                 _ => return Err(Error::UnexpectedToken(next).into())
@@ -167,13 +166,13 @@ impl Parser {
     fn parse_matrix_part(&mut self) -> Result<Vec<Expr>> {
         let mut part = Vec::new();
         loop {
-            let expr = match self.lexer.peek_token()? {
+            let expr = match self.lexer.peek_token()?.data {
                 T::SemiColon => break,
                 T::RightBrack => break,
                 _ => self.parse_expr()?
             };
             part.push(expr);
-            match self.lexer.peek_token()? {
+            match self.lexer.peek_token()?.data {
                 T::Comma => {
                     self.lexer.next_token()?;
                 },
@@ -184,20 +183,21 @@ impl Parser {
     }
 
     fn parse_matrix(&mut self) -> Result<Expr> {
+        let pos = self.lexer.peek_token()?.pos;
         self.force_token(T::LeftBrack)?;
         let mut parts = Vec::new();
         loop {
             let part = self.parse_matrix_part()?;
             parts.push(part);
             let next = self.lexer.next_token()?;
-            match next {
+            match next.data {
                 T::SemiColon => continue,
                 T::RightBrack => break,
                 _ => return Err(Error::UnexpectedToken(next).into()),
             };
         }
         if parts.len() == 1 {
-            Ok(E::List(parts.pop().unwrap()))
+            Ok((E::List(parts.pop().unwrap()), pos).into())
         } else {
             let codomain = parts.len();
             let domain = parts[0].len();
@@ -211,31 +211,32 @@ impl Parser {
             while let Some(part) = parts.pop() {
                 data.extend(part);
             }
-            Ok(E::Matrix((domain, codomain, data)))
+            Ok((E::Matrix((domain, codomain, data)), pos).into())
         }
     }
 
     fn parse_table_key(&mut self) -> Result<Expr> {
         let tok = self.lexer.next_token()?;
-        Ok(match tok {
+        Ok(match tok.data {
             T::LeftBrack => {
                 let expr = self.parse_expr()?;
                 self.force_token(T::RightBrack)?;
                 expr
             },
-            T::Ident(ident) => E::Literal(V::String(ident.to_string().into())),
-            T::String(string) => E::Literal(V::String(string.to_string().into())),
+            T::Ident(ident) => (E::Literal(V::String(ident.to_string().into())), tok.pos).into(),
+            T::String(string) => (E::Literal(V::String(string.to_string().into())), tok.pos).into(),
             _ => return Err(Error::UnexpectedToken(tok).into())
         })
     }
 
     fn parse_table(&mut self) -> Result<Expr> {
+        let pos = self.lexer.peek_token()?.pos;
         self.force_token(T::Colon)?;
         self.force_token(T::LeftBrace)?;
         let mut table = Vec::new();
-        if self.lexer.peek_token()? == T::RightBrace {
+        if self.lexer.peek_token()?.data == T::RightBrace {
             self.lexer.next_token()?;
-            return Ok(E::Table(table))
+            return Ok((E::Table(table), pos).into())
         }
         loop {
             let key = self.parse_table_key()?;
@@ -243,13 +244,13 @@ impl Parser {
             let value = self.parse_expr()?;
             table.push((key, value));
             let next = self.lexer.next_token()?;
-            match next {
+            match next.data {
                 T::Comma => continue,
                 T::RightBrace => break,
                 _ => return Err(Error::UnexpectedToken(next).into())
             }
         }
-        Ok(E::Table(table))
+        Ok((E::Table(table), pos).into())
     }
 
     fn parse_paren(&mut self) -> Result<Expr> {
@@ -259,28 +260,26 @@ impl Parser {
         Ok(expr)
     }
 
-    fn parse_params(&mut self) -> Result<(Vec<Rc<str>>, bool)> {
-        use T::*;
+    fn parse_params(&mut self) -> Result<(Vec<(Rc<str>, Position)>, bool)> {
         let tok = self.lexer.next_token()?;
-        match tok {
-            Ident(ident) => {
-                let params = vec![ident];
-                if self.lexer.peek_token()? == T::Varadic {
+        match tok.data {
+            T::Ident(ident) => {
+                let params = vec![(ident, tok.pos)];
+                if self.lexer.peek_token()?.data == T::Varadic {
                     self.lexer.next_token()?;
                     return Ok((params, true))
                 } else {
                     return Ok((params, false))
                 }
             }
-            LeftParen => (),
+            T::LeftParen => (),
             _ => return Err(Error::UnexpectedToken(tok).into()),
         }
 
         let mut params = Vec::new();
         let mut varadic = false;
 
-        if self.lexer.peek_token()? == T::RightParen {
-            self.lexer.next_token()?;
+        if self.lexer.peek_token()?.data == T::RightParen {
             return Ok((params, varadic));
         }
 
@@ -288,14 +287,14 @@ impl Parser {
             let ident = self.parse_ident()?;
             params.push(ident);
             let next = self.lexer.next_token()?;
-            match next {
-                Varadic => {
+            match next.data {
+                T::Varadic => {
                     varadic = true;
                     self.force_token(T::RightParen)?;
                     break;
                 }
-                Comma => continue,
-                RightParen => break,
+                T::Comma => continue,
+                T::RightParen => break,
                 _ => return Err(Error::UnexpectedToken(next).into()),
             }
         }
@@ -303,103 +302,135 @@ impl Parser {
         Ok((params, varadic))
     }
 
-    fn parse_ident(&mut self) -> Result<Rc<str>> {
-        if let T::Ident(ident) = self.lexer.next_token()? {
-            Ok(ident)
+    fn parse_ident(&mut self) -> Result<AstName> {
+        let next = self.lexer.next_token()?;
+        if let T::Ident(ident) = next.data {
+            Ok((ident, next.pos))
         } else {
-            Err(Error::ExpectedTokenName("Ident").into())
+            Err(Error::UnexpectedToken(next).into())
         }
     }
 
-    fn parse_ident_nl(&mut self) -> Result<Rc<str>> {
-        if let T::Ident(ident) = self.lexer.next_token_nl()? {
+    fn parse_wrapped_ident(&mut self) -> Result<AstName> {
+        if self.lexer.peek_token()?.data == T::LeftParen {
+            self.lexer.next_token()?;
+            let ident = self.parse_ident()?;
+            self.force_token(T::RightParen)?;
             Ok(ident)
         } else {
-            Err(Error::ExpectedTokenName("Ident").into())
+            self.parse_ident()
+        }
+    }
+
+    fn parse_ident_nl(&mut self) -> Result<AstName> {
+        let next = self.lexer.next_token_nl()?;
+        if let T::Ident(ident) = next.data {
+            Ok((ident, next.pos))
+        } else {
+            Err(Error::UnexpectedToken(next).into())
         }
     }
 
     fn parse_function(&mut self) -> Result<Expr> {
+        let pos = self.lexer.peek_token()?.pos;
         self.force_token(T::Function)?;
         let ident = self.parse_ident()?;
-        let (params, varadic) = match self.lexer.peek_token()? {
+        let (params, varadic) = match self.lexer.peek_token()?.data {
             T::LeftBrace => (vec![], false),
             _ => self.parse_params()?,
         };
         let expr = self.parse_expr()?;
-        Ok(E::Function(ident, params, Box::new(expr), varadic))
+        Ok((E::Function(ident, params, Box::new(expr), varadic), pos).into())
     }
 
     fn parse_lambda(&mut self) -> Result<Expr> {
+        let pos = self.lexer.peek_token()?.pos;
         self.force_token(T::Backslash)?;
-        let (params, varadic) = match self.lexer.peek_token()? {
+        let (params, varadic) = match self.lexer.peek_token()?.data {
             T::Arrow => (vec![], false),
             _ => self.parse_params()?,
         };
         self.force_token(T::Arrow)?;
         let expr = self.parse_expr()?;
-        Ok(E::Lambda(params, Box::new(expr), varadic))
+        Ok((E::Lambda(params, Box::new(expr), varadic), pos).into())
     }
 
     fn parse_do_while(&mut self) -> Result<Expr> {
+        let pos = self.lexer.peek_token()?.pos;
         self.force_token(T::Do)?;
         let expr = Box::new(self.parse_expr()?);
         self.force_token(T::While)?;
         let cond = Box::new(self.parse_expr()?);
-        Ok(E::DoWhile(expr, cond))
+        Ok((E::DoWhile(expr, cond), pos).into())
     }
 
     fn parse_while(&mut self) -> Result<Expr> {
+        let pos = self.lexer.peek_token()?.pos;
         self.force_token(T::While)?;
         let cond = Box::new(self.parse_expr()?);
         let expr = Box::new(self.parse_expr()?);
-        Ok(E::While(cond, expr))
+        Ok((E::While(cond, expr), pos).into())
     }
 
     fn parse_loop(&mut self) -> Result<Expr> {
+        let pos = self.lexer.peek_token()?.pos;
         self.force_token(T::Loop)?;
         let expr = self.parse_expr()?;
-        Ok(E::Loop(Box::new(expr)))
+        Ok((E::Loop(Box::new(expr)), pos).into())
+    }
+
+    fn parse_for(&mut self) -> Result<Expr> {
+        let pos = self.lexer.peek_token()?.pos;
+        self.force_token(T::For)?;
+        let name = self.parse_ident()?;
+        self.force_token(T::In)?;
+        let cond = Box::new(self.parse_expr()?);
+        let expr = Box::new(self.parse_expr()?);
+        Ok((E::For(name, cond, expr), pos).into())
     }
 
     fn parse_if(&mut self) -> Result<Expr> {
+        let pos = self.lexer.peek_token()?.pos;
         self.force_token(T::If)?;
         let cond = Box::new(self.parse_expr()?);
         let expr = Box::new(self.parse_expr()?);
 
-        if self.lexer.peek_token()? != T::Else {
-            return Ok(E::If(cond, expr, None))
+        if self.lexer.peek_token()?.data != T::Else {
+            return Ok((E::If(cond, expr, None), pos).into())
         }
         self.lexer.next_token()?;
 
-        if self.lexer.peek_token()? == T::If {
-            Ok(E::If(cond, expr, Some(Box::new(self.parse_if()?))))
+        if self.lexer.peek_token()?.data == T::If {
+            Ok((E::If(cond, expr, Some(Box::new(self.parse_if()?))), pos).into())
         } else {
-            Ok(E::If(cond, expr, Some(Box::new(self.parse_expr()?))))
+            Ok((E::If(cond, expr, Some(Box::new(self.parse_expr()?))), pos).into())
         }
     }
 
     fn parse_let(&mut self) -> Result<Expr> {
+        let pos = self.lexer.peek_token()?.pos;
         self.force_token(T::Let)?;
         let ident = self.parse_ident_nl()?;
-        if self.lexer.peek_token_nl()? == T::Assign {
+        if self.lexer.peek_token_nl()?.data == T::Assign {
             self.force_token_nl(T::Assign)?;
-            Ok(E::Let(ident, Box::new(self.parse_expr()?)))
+            Ok((E::Let(ident, Box::new(self.parse_expr()?)), pos).into())
         } else {
-            Ok(E::Let(ident, Box::new(E::Literal(V::Nil))))
+            Ok((E::Let(ident, Box::new((E::Literal(V::Nil), pos).into())), pos).into())
         }
     }
 
     fn parse_return(&mut self) -> Result<Expr> {
+        let pos = self.lexer.peek_token()?.pos;
         self.force_token(T::Return)?;
-        Ok(E::Return(Box::new(self.parse_expr()?)))
+        Ok((E::Return(Box::new(self.parse_expr()?)), pos).into())
     }
 
     fn parse_block(&mut self) -> Result<Expr> {
         let mut block = Vec::new();
+        let pos = self.lexer.peek_token()?.pos;
         self.force_token(T::LeftBrace)?;
         loop {
-            let expr = match self.lexer.peek_token()? {
+            let expr = match self.lexer.peek_token()?.data {
                 T::RightBrace => break,
                 T::SemiColon => {
                     self.lexer.next_token()?;
@@ -408,22 +439,32 @@ impl Parser {
                 _ => self.parse_expr()?
             };
             block.push(expr);
-            let next = self.lexer.next_token()?;
-            match next {
+            let next = self.lexer.next_token_nl()?;
+            match next.data {
                 T::SemiColon => continue,
                 T::RightBrace => break,
-                _ => return Err(Error::ExpectedToken(T::SemiColon).into())
+                _ => return Err(Error::ExpectedToken(T::SemiColon, next.pos).into())
             }
         }
-        if self.lexer.peek_token()? == T::RightBrace {
+        if self.lexer.peek_token()?.data == T::RightBrace {
             self.lexer.next_token()?;
         }
-        Ok(E::Block(block))
+        Ok((E::Block(block), pos).into())
+    }
+
+    fn parse_try(&mut self) -> Result<Expr> {
+        let pos = self.lexer.peek_token()?.pos;
+        self.force_token(T::Try)?;
+        let expr = self.parse_expr()?;
+        self.force_token(T::Catch)?;
+        let ident = self.parse_wrapped_ident()?;
+        let catch = self.parse_expr()?;
+        Ok((E::Try(Box::new(expr), ident, Box::new(catch)), pos).into())
     }
 
     fn parse_value(&mut self) -> Result<Expr> {
         let tok = self.lexer.next_token()?;
-        Ok(match tok {
+        let data = match tok.data {
             T::Nil => E::Literal(V::Nil),
             T::Int(i) => E::Literal(V::Int(i)),
             T::Float(f) => E::Literal(V::Float(f)),
@@ -434,28 +475,31 @@ impl Parser {
             T::False => E::Literal(V::Bool(false)),
             T::Ident(ident) => E::Ident(ident),
             _ => return Err(Error::UnexpectedToken(tok).into()),
-        })
+        };
+        Ok((data, tok.pos).into())
     }
 
     fn parse_term(&mut self) -> Result<Expr> {
         use T::*;
-        match self.lexer.peek_token()? {
+        match self.lexer.peek_token()?.data {
             Function => self.parse_function(),
             Backslash => self.parse_lambda(),
             Do => self.parse_do_while(),
             While => self.parse_while(),
+            For => self.parse_for(),
             Let => self.parse_let(),
             LeftBrace => self.parse_block(),
             Return => self.parse_return(),
             If => self.parse_if(),
             Loop => self.parse_loop(),
+            Try => self.parse_try(),
             Break => {
-                self.lexer.next_token()?;
-                Ok(E::Break)
+                let next = self.lexer.next_token()?;
+                Ok((E::Break, next.pos).into())
             },
             Continue => {
-                self.lexer.next_token()?;
-                Ok(E::Continue)
+                let next = self.lexer.next_token()?;
+                Ok((E::Continue, next.pos).into())
             },
             LeftBrack => self.parse_matrix(),
             Colon => self.parse_table(),
@@ -466,13 +510,14 @@ impl Parser {
 
     fn parse_expr_expr_access(&mut self) -> Result<Expr> {
         let mut expr = self.parse_term()?;
+        let pos = expr.pos;
         loop {
             let tok = self.lexer.peek_token()?;
-            match tok {
+            match tok.data {
                 T::Access => {
                     self.force_token(T::Access)?;
                     let temp = self.parse_ident()?;
-                    expr = E::FieldAccess(Box::new(expr), temp);
+                    expr = (E::FieldAccess(Box::new(expr), temp), pos).into();
                 },
                 _ => break
             }
@@ -482,16 +527,17 @@ impl Parser {
 
     fn parse_expr_call(&mut self) -> Result<Expr> {
         let mut expr = self.parse_expr_expr_access()?;
+        let pos = expr.pos;
         loop {
             let tok = self.lexer.peek_token()?;
-            match tok {
+            match tok.data {
                 T::LeftBrack => {
                     let index = self.parse_index()?;
-                    expr = E::Index(Box::new(expr), index);
+                    expr = (E::Index(Box::new(expr), index), pos).into();
                 },
                 T::LeftParen => {
                     let params = self.parse_fn_call()?;
-                    expr = E::FnCall(Box::new(expr), params);
+                    expr = (E::FnCall(Box::new(expr), params), pos).into();
                 }
                 _ => break
             }
@@ -501,14 +547,14 @@ impl Parser {
 
     fn parse_expr_unary(&mut self) -> Result<Expr> {
         let tok = self.lexer.peek_token_nl()?;
-        Ok(match tok {
+        Ok(match tok.data {
             T::Not => {
                 self.lexer.next_token()?;
-                E::UnaryOp(Box::new(self.parse_expr_unary()?), UnaryOp::Not)
+                (E::UnaryOp(Box::new(self.parse_expr_unary()?), UnaryOp::Not), tok.pos).into()
             }
             T::Subtract => {
                 self.lexer.next_token()?;
-                E::UnaryOp(Box::new(self.parse_expr_unary()?), UnaryOp::Negate)
+                (E::UnaryOp(Box::new(self.parse_expr_unary()?), UnaryOp::Negate), tok.pos).into()
             }
             _ => self.parse_expr_call()?
         })
@@ -559,13 +605,14 @@ impl Parser {
 
     fn parse_expr_and(&mut self) -> Result<Expr> {
         let mut expr = self.parse_expr_compare()?;
+        let pos = expr.pos;
         loop {
             let tok = self.lexer.peek_token()?;
-            match tok {
+            match tok.data {
                 T::And => {
                     self.force_token(T::And)?;
                     let temp = self.parse_expr_compare()?;
-                    expr = E::And(Box::new(expr), Box::new(temp));
+                    expr = (E::And(Box::new(expr), Box::new(temp)), pos).into();
                 },
                 _ => break
             }
@@ -575,13 +622,14 @@ impl Parser {
 
     fn parse_expr_or(&mut self) -> Result<Expr> {
         let mut expr = self.parse_expr_and()?;
+        let pos = expr.pos;
         loop {
             let tok = self.lexer.peek_token()?;
-            match tok {
+            match tok.data {
                 T::Or => {
                     self.force_token(T::Or)?;
                     let temp = self.parse_expr_and()?;
-                    expr = E::Or(Box::new(expr), Box::new(temp));
+                    expr = (E::Or(Box::new(expr), Box::new(temp)), pos).into();
                 },
                 _ => break
             }
@@ -589,75 +637,112 @@ impl Parser {
         Ok(expr)
     }
 
-    fn parse_expr(&mut self) -> Result<Expr> {
-        use BinaryOp as B;
+    fn parse_expr_range(&mut self) -> Result<Expr> {
         let expr = self.parse_expr_or()?;
+        let pos = expr.pos;
+        match self.lexer.peek_token()?.data {
+            T::Range => {
+                self.lexer.next_token()?;
+                let temp = self.parse_expr_or()?;
+                Ok((E::BinaryOp(Box::new(expr), Box::new(temp), BinaryOp::Range), pos).into())
+            },
+            T::RangeEq => {
+                self.lexer.next_token()?;
+                let temp = self.parse_expr_or()?;
+                Ok((E::BinaryOp(Box::new(expr), Box::new(temp), BinaryOp::RangeEq), pos).into())
+            },
+            _ => Ok(expr)
+        }
+    }
+
+    fn parse_expr_op_assign(&mut self) -> Result<Expr> {
+        use BinaryOp as B;
+        let expr = self.parse_expr_range()?;
         let tok = self.lexer.peek_token_nl()?;
-        Ok(match tok {
+        let pos = tok.pos;
+        let data: ExprData = match tok.data {
             T::Assign => {
                 self.lexer.next_token_nl()?;
                 E::Assign(Box::new(expr.clone()),Box::new(self.parse_expr()?))
             },
             T::AssignAnd => {
                 self.lexer.next_token_nl()?;
-                E::Assign(Box::new(expr.clone()),Box::new(E::And(Box::new(expr), Box::new(self.parse_expr()?))))
+                E::Assign(Box::new(expr.clone()),Box::new((E::And(Box::new(expr), Box::new(self.parse_expr()?)), pos).into()))
             },
             T::AssignOr => {
                 self.lexer.next_token_nl()?;
-                E::Assign(Box::new(expr.clone()),Box::new(E::Or(Box::new(expr), Box::new(self.parse_expr()?))))
+                E::Assign(Box::new(expr.clone()),Box::new((E::Or(Box::new(expr), Box::new(self.parse_expr()?)),pos).into()))
             },
             T::AssignAdd => {
                 self.lexer.next_token_nl()?;
-                E::Assign(Box::new(expr.clone()),Box::new(E::BinaryOp(Box::new(expr), Box::new(self.parse_expr()?), B::Add)))
+                E::Assign(Box::new(expr.clone()),Box::new((E::BinaryOp(Box::new(expr), Box::new(self.parse_expr()?), B::Add),pos).into()))
             },
             T::AssignSubtract => {
                 self.lexer.next_token_nl()?;
-                E::Assign(Box::new(expr.clone()),Box::new(E::BinaryOp(Box::new(expr), Box::new(self.parse_expr()?), B::Subtract)))
+                E::Assign(Box::new(expr.clone()),Box::new((E::BinaryOp(Box::new(expr), Box::new(self.parse_expr()?), B::Subtract),pos).into()))
             },
             T::AssignMultiply => {
                 self.lexer.next_token_nl()?;
-                E::Assign(Box::new(expr.clone()),Box::new(E::BinaryOp(Box::new(expr), Box::new(self.parse_expr()?), B::Multiply)))
+                E::Assign(Box::new(expr.clone()),Box::new((E::BinaryOp(Box::new(expr), Box::new(self.parse_expr()?), B::Multiply),pos).into()))
             },
             T::AssignDivide => {
                 self.lexer.next_token_nl()?;
-                E::Assign(Box::new(expr.clone()),Box::new(E::BinaryOp(Box::new(expr), Box::new(self.parse_expr()?), B::Divide)))
+                E::Assign(Box::new(expr.clone()),Box::new((E::BinaryOp(Box::new(expr), Box::new(self.parse_expr()?), B::Divide),pos).into()))
             },
             T::AssignModulo => {
                 self.lexer.next_token_nl()?;
-                E::Assign(Box::new(expr.clone()),Box::new(E::BinaryOp(Box::new(expr), Box::new(self.parse_expr()?), B::Modulo)))
+                E::Assign(Box::new(expr.clone()),Box::new((E::BinaryOp(Box::new(expr), Box::new(self.parse_expr()?), B::Modulo),pos).into()))
             },
             T::AssignPower => {
                 self.lexer.next_token_nl()?;
-                E::Assign(Box::new(expr.clone()),Box::new(E::BinaryOp(Box::new(expr), Box::new(self.parse_expr()?), B::Power)))
+                E::Assign(Box::new(expr.clone()),Box::new((E::BinaryOp(Box::new(expr), Box::new(self.parse_expr()?), B::Power),pos).into()))
             },
             T::AssignBitwiseAnd => {
                 self.lexer.next_token_nl()?;
-                E::Assign(Box::new(expr.clone()),Box::new(E::BinaryOp(Box::new(expr), Box::new(self.parse_expr()?), B::BitwiseAnd)))
+                E::Assign(Box::new(expr.clone()),Box::new((E::BinaryOp(Box::new(expr), Box::new(self.parse_expr()?), B::BitwiseAnd),pos).into()))
             },
             T::AssignBitwiseOr => {
                 self.lexer.next_token_nl()?;
-                E::Assign(Box::new(expr.clone()),Box::new(E::BinaryOp(Box::new(expr), Box::new(self.parse_expr()?), B::BitwiseOr)))
+                E::Assign(Box::new(expr.clone()),Box::new((E::BinaryOp(Box::new(expr), Box::new(self.parse_expr()?), B::BitwiseOr),pos).into()))
             },
             T::AssignBitwiseXor => {
                 self.lexer.next_token_nl()?;
-                E::Assign(Box::new(expr.clone()),Box::new(E::BinaryOp(Box::new(expr), Box::new(self.parse_expr()?), B::BitwiseXor)))
+                E::Assign(Box::new(expr.clone()),Box::new((E::BinaryOp(Box::new(expr), Box::new(self.parse_expr()?), B::BitwiseXor),pos).into()))
             },
             T::AssignBitwiseShiftLeft => {
                 self.lexer.next_token_nl()?;
-                E::Assign(Box::new(expr.clone()),Box::new(E::BinaryOp(Box::new(expr), Box::new(self.parse_expr()?), B::BitwiseShiftLeft)))
+                E::Assign(Box::new(expr.clone()),Box::new((E::BinaryOp(Box::new(expr), Box::new(self.parse_expr()?), B::BitwiseShiftLeft),pos).into()))
             },
             T::AssignBitwiseShiftRight => {
                 self.lexer.next_token_nl()?;
-                E::Assign(Box::new(expr.clone()),Box::new(E::BinaryOp(Box::new(expr), Box::new(self.parse_expr()?), B::BitwiseShiftRight)))
+                E::Assign(Box::new(expr.clone()),Box::new((E::BinaryOp(Box::new(expr), Box::new(self.parse_expr()?), B::BitwiseShiftRight),pos).into()))
             },
-            _ => expr
-        })
+            _ => expr.data
+        };
+        Ok((data, pos).into())
+    }
+
+    fn parse_expr(&mut self) -> Result<Expr> {
+        let mut expr = self.parse_expr_op_assign()?;
+        let pos = expr.pos;
+        loop {
+            let tok = self.lexer.peek_token()?;
+            match tok.data {
+                T::Pipe => {
+                    self.force_token(T::Pipe)?;
+                    let temp = self.parse_expr_op_assign()?;
+                    expr = (E::Pipeline(Box::new(expr), Box::new(temp)), pos).into();
+                },
+                _ => break
+            }
+        }
+        Ok(expr)
     }
 
     fn parse_root(&mut self) -> Result<Expr> {
         let mut block = Vec::new();
         loop {
-            match self.lexer.peek_token()? {
+            match self.lexer.peek_token()?.data {
                 T::Eof => break,
                 T::SemiColon => {
                     self.lexer.next_token()?;
@@ -667,13 +752,14 @@ impl Parser {
             };
             let expr = self.parse_expr()?;
             block.push(expr);
-            match self.lexer.next_token()? {
+            let next = self.lexer.next_token()?;
+            match next.data {
                 T::Eof => break,
                 T::SemiColon => continue,
-                _ => return Err(Error::ExpectedToken(T::SemiColon).into())
+                _ => return Err(Error::ExpectedToken(T::SemiColon, next.pos).into())
             };
         }
-        Ok(E::Block(block))
+        Ok((E::Block(block), Position::default()).into())
     }
 
     pub fn parse<T: Into<String>>(&mut self, into: T) -> Result<Expr> {
diff --git a/matrix/src/value.rs b/matrix/src/value.rs
index 2c86226..3ebc48a 100644
--- a/matrix/src/value.rs
+++ b/matrix/src/value.rs
@@ -1,5 +1,14 @@
-use std::{collections::HashMap, rc::Rc, hash::Hash, fmt::{Display, Debug}, ops::{Add, Neg, Not, Sub, Div, Mul, BitOr, BitAnd, BitXor, Shl, Shr}, cmp::Ordering};
+use std::{
+    collections::HashMap,
+    rc::Rc,
+    hash::Hash,
+    fmt::{Display, Debug},
+    ops::{Add, Neg, Not, Sub, Div, Mul, BitOr, BitAnd, BitXor, Shl, Shr},
+    cmp::Ordering,
+    cell::RefCell, fs::File
+};
 
+use crate::iter;
 use num_complex::Complex64;
 use num_rational::Rational64;
 use regex::Regex;
@@ -29,67 +38,29 @@ impl ValueMap {
         self.0.insert(key, value);
         Ok(())
     }
+    pub fn len(&self) -> usize {
+        self.0.len()
+    }
 }
 
 #[derive(Debug)]
-pub enum Error {
-    Neg(Value),
-    Add(Value, Value),
-    Subtract(Value, Value),
-    Multiply(Value, Value),
-    Divide(Value, Value),
-    Modulo(Value, Value),
-    Exponent(Value, Value),
-    Compare(Value, Value),
-    IndexOutOfBounds(i64, usize),
-    MatrixOutOfBounds(usize, usize, usize, usize),
-    MatrixIndexOutOfBounds(i64, usize, usize),
-    MatrixInvSlice(usize, usize),
-    MatrixMultiply(usize, usize),
-    MatrixAdd(usize, usize, usize, usize),
-    CannotIndex(Value),
-    BadIndex(Value, Value),
-    Concat(Value, Value),
-    Bitwise(Value, Value),
-    DivideByZero,
-    ZeroExpZero,
-    CannotHash(Value),
-    FieldAccess(Value),
-}
+pub struct Error(String);
 
 impl Display for self::Error {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        use self::Error::*;
-        match self {
-            Neg(v) => write!(f, "cannot negate {v:?}"),
-            Add(a, b) => write!(f, "cannot add {a:?} to {b:?}"),
-            Subtract(a, b) => write!(f, "cannot subtract {a:?} from {b:?}"),
-            Multiply(a, b) => write!(f, "cannot multiply {a:?} and {b:?}"),
-            Divide(a, b) => write!(f, "cannot divide {a:?} and {b:?}"),
-            Modulo(a, b) => write!(f, "cannot modulo {a:?} and {b:?}"),
-            Exponent(a, b) => write!(f, "cannot compute {a:?} pow {b:?}"),
-            Compare(a, b) => write!(f, "cannot compare {a:?} and {b:?}"),
-            IndexOutOfBounds(a, b) => write!(f, "index {a} out of bounds for list of length {b}"),
-            MatrixOutOfBounds(a, b, c, d) => write!(f, "row col ({a},{b}) is out of bounds for matrix {c}x{d}"),
-            MatrixIndexOutOfBounds(i, d, c) => write!(f, "row index {i} is out of bounds for matrix {d}x{c}"),
-            MatrixMultiply(c, d) => write!(f, "cannot multiply a matrix with the domain of {d} and matrix with the codomain of {c}"),
-            MatrixAdd(a, b, c, d) => write!(f, "cannot add a {a}x{b} matrix and a {c}x{d} matrix"),
-            MatrixInvSlice(s, e) => write!(f, "invalid matrix slice {s}..{e}"),
-            BadIndex(a, b) => write!(f, "cannot index {a:?} with {b:?}"),
-            CannotIndex(a) => write!(f, "cannot index {a:?}"),
-            Concat(a, b) => write!(f, "cannot concat {a:?} and {b:?}"),
-            Bitwise(a, b) => write!(f, "cannot bitwise between {a:?} and {b:?}"),
-            DivideByZero => write!(f, "attempted to divide by zero"),
-            ZeroExpZero => write!(f, "cannot exponent zero with zero"),
-            CannotHash(v) => write!(f, "cannot hash {v:?}"),
-            FieldAccess(a) => write!(f, "{a:?} cannot be field accessed"),
-        }
+        write!(f, "{}", self.0)
     }
 }
 
 impl std::error::Error for self::Error {}
 
-#[derive(Debug, Clone)]
+macro_rules! error {
+    ($($arg:tt)*) => {
+        Err(self::Error(format!($($arg)*)).into())
+    };
+}
+
+#[derive(Clone)]
 pub enum Value {
     Nil,
     Bool(bool),
@@ -98,11 +69,21 @@ pub enum Value {
     Ratio(Rational64),
     Complex(Complex64),
     Regex(Rc<Regex>),
-    String(Rc<String>),
+    String(Rc<str>),
     List(Gc<List>),
     Matrix(Gc<Matrix>),
     Table(Gc<Table>),
     Function(Rc<Function>),
+    Range(Rc<(i64, i64, bool)>),
+    Iter(Rc<Function>),
+    File(Rc<RefCell<File>>),
+    Error(crate::Error),
+}
+
+impl From<&str> for Value {
+    fn from(value: &str) -> Self {
+        Value::String(value.into())
+    }
 }
 
 impl Hash for Value {
@@ -132,145 +113,175 @@ impl Hash for Value {
     }
 }
 
-impl Value {
-    pub fn can_hash(&self) -> Result<()> {
-        use Value::*;
+impl Debug for Value {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        use Value as V;
         match self {
-            Nil => {},
-            Bool(_) => {},
-            Int(_) => {},
-            Ratio(_) => {},
-            Regex(_) => {},
-            String(_) => {}
-            List(l) => {
-                for val in l.iter() {
-                    val.can_hash()?;
-                }
-            }
-            Matrix(m) => {
-                for val in m.values.iter() {
-                    val.can_hash()?;
-                }
-            },
-            _ => return Err(Error::CannotHash(self.clone()).into())
+            V::Nil => write!(f, "[Nil]"),
+            V::Bool(b) => write!(f, "[Bool {b}]"),
+            V::Int(i) => write!(f, "[Int {i}]"),
+            V::Float(vf) => write!(f, "[Float {vf}]"),
+            V::Ratio(r) => write!(f, "[Ratio {r}]"),
+            V::Complex(c) => write!(f, "[Complex {c}]"),
+            V::Regex(r) => write!(f, "[Regex /{r}/]"),
+            V::String(s) => write!(f, "[String '{s}']"),
+            V::List(l) => write!(f, "[List {}]", l.len()),
+            V::Matrix(m) => write!(f, "[Matirx {}x{}]", m.domain, m.codomain),
+            V::Table(t) => write!(f, "[Table {}]", t.0.len()),
+            V::Function(vf) => write!(f, "[Function {}]", vf.name),
+            V::Range(r) => write!(f, "[Range {:?}..{:?}]", r.0, r.1),
+            V::Iter(_) => write!(f, "[Iterator]"),
+            V::Error(_) => write!(f, "[Error]"),
+            V::File(_) => write!(f, "[File]"),
         }
-        Ok(())
     }
+}
+
+impl Display for Value {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        use Value as V;
+
+        let red;
+        let green;
+        let yellow;
+        let blue;
+        let pink;
+        let cyan;
+        let clear;
+
+        if f.alternate() {
+            red = "\x1b[31m";
+            green = "\x1b[32m";
+            yellow = "\x1b[33m";
+            blue = "\x1b[34m";
+            pink = "\x1b[35m";
+            cyan = "\x1b[36m";
+            clear = "\x1b[0m";
+        } else {
+            red = "";
+            green = "";
+            yellow = "";
+            blue = "";
+            pink = "";
+            cyan = "";
+            clear = "";
+        }
 
-    pub fn boring_print(&self) -> String {
-        use Value::*;
         match self {
-            Nil => format!("nil"),
-            Bool(b) => format!("{b}"),
-            Int(i) => format!("{i}"),
-            Float(l) => format!("{l}"),
-            Ratio(r) => format!("{r}"),
-            Complex(c) => format!("{c}"),
-            Regex(r) => format!("/{r}/"),
-            String(s) => format!("{s}"),
-            List(l) => {
-                let mut str = "[".to_string();
+            V::Nil => {write!(f, "{blue}nil{clear}")?;},
+            V::Bool(b) => {write!(f, "{yellow}{b}{clear}")?;},
+            V::Int(i) => {write!(f, "{yellow}{i}{clear}")?;},
+            V::Float(l) => {write!(f, "{yellow}{l}{clear}")?;},
+            V::Ratio(r) => {write!(f, "{yellow}{r}{clear}")?;},
+            V::Complex(c) => {write!(f, "{yellow}{c}{clear}")?;},
+            V::Regex(r) => {write!(f, "/{red}{r}{clear}/")?;},
+            V::String(s) => {
+                if f.alternate() {
+                    write!(f, "{green}'{s}'{clear}")?;
+                } else {
+                    write!(f, "{s}")?;
+                }
+            }
+            V::List(l) => {
+                write!(f, "[")?;
                 for (i, el) in l.iter().enumerate() {
                     if i != 0 {
-                        str.push_str(" ");
+                        write!(f, " ")?;
+                    }
+                    if f.alternate() {
+                        write!(f, "{el:#}")?;
+                    } else {
+                        write!(f, "{el}")?;
                     }
-                    str.push_str(&el.boring_print());
                 }
-                str.push_str("]");
-                str
+                write!(f, "]")?;
             },
-            Matrix(m) => {
-                let mut str = "\n".to_string();
+            V::Matrix(m) => {
+                write!(f, "\n")?;
                 for row in m.rows() {
-                    str.push_str("  ");
-                    for (i, v) in row.into_iter().enumerate() {
+                    write!(f, "  ")?;
+                    for (i, el) in row.into_iter().enumerate() {
                         if i != 0 {
-                            str.push(' ');
+                            write!(f, " ")?;
+                        }
+                        if f.alternate() {
+                            write!(f, "{el:#}")?;
+                        } else {
+                            write!(f, "{el}")?;
                         }
-                        str.push_str(&v.boring_print());
                     }
-                    str.push('\n');
+                    write!(f, "\n")?;
                 }
-                str
             },
-            Table(t) => {
-                let mut str = "{".to_string();
+            V::Table(t) => {
+                write!(f, "{{")?;
                 for (i, (key, val)) in t.0.iter().enumerate() {
                     if i != 0 {
-                        str.push_str(", ");
+                        write!(f, ", ")?;
+                    }
+                    if f.alternate() {
+                        write!(f, "{key:#} = {val:#}")?;
+                    } else {
+                        write!(f, "{key} = {val}")?;
                     }
-                    str.push_str(&key.boring_print());
-                    str.push_str(" = ");
-                    str.push_str(&val.boring_print());
                 }
-                str.push_str("}");
-                str
+                write!(f, "}}")?;
             },
-            Function(fun) => {
-                format!("{fun:?}")
+            V::Function(fun) => {
+                use crate::chunk::InnerFunction as F;
+                match fun.fun {
+                    F::Compiled(_) => write!(f, "{cyan}[Function {}]{clear}", fun.name)?,
+                    F::Native(_) => write!(f, "{cyan}[Builtin {}]{clear}", fun.name)?,
+                };
+            },
+            V::Range(r) => {
+                if f.alternate() {
+                    write!(f, "{:#}..{:#}", r.0, r.1)?;
+                } else {
+                    write!(f, "{}..{}", r.0, r.1)?;
+                }
             }
-        }
+            V::Iter(_) => {write!(f, "{pink}[Iterator]{clear}")?;},
+            V::File(_) => {write!(f, "{pink}[File]{clear}")?;},
+            V::Error(e) => {write!(f, "{red}{e}{clear}")?;},
+        };
+        Ok(())
     }
+}
 
-    pub fn pretty_print(&self) -> String {
+impl Value {
+    pub fn can_hash(&self) -> Result<()> {
         use Value::*;
         match self {
-            Nil => format!("\x1b[34m{}\x1b[0m", self.boring_print()),
-            Bool(_) => format!("\x1b[33m{}\x1b[0m", self.boring_print()),
-            Int(_) => format!("\x1b[33m{}\x1b[0m", self.boring_print()),
-            Float(_) => format!("\x1b[33m{}\x1b[0m", self.boring_print()),
-            Ratio(_) => format!("\x1b[33m{}\x1b[0m", self.boring_print()),
-            Complex(_) => format!("\x1b[33m{}\x1b[0m", self.boring_print()),
-            Regex(_) => format!("\x1b[31m{}\x1b[0m", self.boring_print()),
-            String(_) => format!("\x1b[32m'{}'\x1b[0m", self.boring_print()),
+            Nil => {},
+            Bool(_) => {},
+            Int(_) => {},
+            Ratio(_) => {},
+            Regex(_) => {},
+            String(_) => {}
             List(l) => {
-                let mut str = "[".to_string();
-                for (i, el) in l.iter().enumerate() {
-                    if i != 0 {
-                        str.push_str(" ");
-                    }
-                    str.push_str(&el.pretty_print());
+                for val in l.iter() {
+                    val.can_hash()?;
                 }
-                str.push_str("]");
-                str
-            },
+            }
             Matrix(m) => {
-                let mut str = "\n".to_string();
-                for row in m.rows() {
-                    str.push_str("  ");
-                    for (i, v) in row.into_iter().enumerate() {
-                        if i != 0 {
-                            str.push(' ');
-                        }
-                        str.push_str(&v.pretty_print());
-                    }
-                    str.push('\n');
-                }
-                str
-            },
-            Table(t) => {
-                let mut str = "{".to_string();
-                for (i, (key, val)) in t.0.iter().enumerate() {
-                    if i != 0 {
-                        str.push_str(", ");
-                    }
-                    str.push_str(&key.pretty_print());
-                    str.push_str(" = ");
-                    str.push_str(&val.pretty_print());
+                for val in m.values.iter() {
+                    val.can_hash()?;
                 }
-                str.push_str("}");
-                str
-            },
-            Function(_) => {
-                format!("\x1b[36m{}\x1b[0m", self.boring_print())
             },
+            _ => return error!("cannot hash {self:?}")
         }
+        Ok(())
     }
-}
 
-impl Display for Value {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(f, "{}", self.pretty_print())
+    pub fn is_zero(&self) -> bool {
+        use Value as V;
+        match self {
+            V::Int(i) => *i == 0,
+            V::Float(f) => *f == 0.0 || *f == -0.0,
+            V::Ratio(r) => *r.numer() == 0,
+            _ => false,
+        }
     }
 }
 
@@ -278,6 +289,17 @@ fn ratio_to_f64(r: Rational64) -> f64 {
 	*r.numer() as f64 / *r.denom() as f64
 }
 
+impl Value {
+    pub fn promote_trig(self) -> Self {
+        use Value as V;
+        match self {
+            V::Int(i) => V::Float(i as f64),
+            V::Ratio(r) => V::Float(ratio_to_f64(r)),
+            a => a
+        }
+    }
+}
+
 fn promote(a: Value, b: Value) -> (Value, Value) {
 	use Value as V;
 	match (&a, &b) {
@@ -293,9 +315,12 @@ fn promote(a: Value, b: Value) -> (Value, Value) {
 		(V::Float(..),   V::Ratio(y))    => (a, V::Float(ratio_to_f64(*y))),
 		(V::Complex(..), V::Ratio(y))    => (a, V::Complex(ratio_to_f64(*y).into())),
 		(V::Complex(..), V::Float(y))    => (a, V::Complex((*y).into())),
-        (V::List(l1),    V::List(l2))    => (V::Matrix(Matrix::from_list(l1.to_vec()).into()), V::Matrix(Matrix::from_list(l2.to_vec()).into())),
-        (_,              V::List(l))     => (a, V::Matrix(Matrix::from_list(l.to_vec()).into())),
-        (V::List(l),     _)              => (V::Matrix(Matrix::from_list(l.to_vec()).into()), b),
+        (V::List(l1),    V::List(l2)) if l1.len() > 0 && l2.len() > 0
+            => (V::Matrix(Matrix::from_list(l1.to_vec()).into()), V::Matrix(Matrix::from_list(l2.to_vec()).into())),
+        (_, V::List(l)) if l.len() > 0
+            => (a, V::Matrix(Matrix::from_list(l.to_vec()).into())),
+        (V::List(l), _) if l.len() > 0
+            => (V::Matrix(Matrix::from_list(l.to_vec()).into()), b),
 		_ => (a, b),
 	}
 }
@@ -310,17 +335,19 @@ impl Add for Value {
 			(Ratio(x), Ratio(y)) => Ok(Ratio(x + y)),
 			(Complex(x), Complex(y)) => Ok(Complex(x + y)),
             (Matrix(x), Matrix(y)) => Ok(Matrix((x + y)?.into())),
-            (String(str), value) => Ok(String(Rc::new(
-                format!("{str}{}", value.boring_print())
+            (Matrix(x), r) => Ok(Matrix(x.increment(r)?.into())),
+            (l, Matrix(y)) => Ok(Matrix(y.increment(l)?.into())),
+            (String(str), value) => Ok(String(Rc::from(
+                format!("{str}{value}")
             ))),
-            (value, String(str)) => Ok(String(Rc::new(
-                format!("{}{str}", value.boring_print())
+            (value, String(str)) => Ok(String(Rc::from(
+                format!("{value}{str}")
             ))),
 			(List(mut l1), List(l2)) => {
 				l1.extend_from_slice(&l2);
 				Ok(List(l1))
 			},
-			(l, r) => Err(Error::Add(l, r).into())
+            (l, r) => error!("cannot add: {l:?} + {r:?}")
 		}
     }
 }
@@ -335,7 +362,8 @@ impl Sub for Value {
 			(Ratio(x), Ratio(y)) => Ok(Ratio(x - y)),
 			(Complex(x), Complex(y)) => Ok(Complex(x - y)),
             (Matrix(x), Matrix(y)) => Ok(Matrix((x - y)?.into())),
-			(l, r) => Err(Error::Subtract(l, r).into())
+            (Matrix(x), r) => Ok(Matrix(x.decrement(r)?.into())),
+            (l, r) => error!("cannot subtract: {l:?} - {r:?}")
 		}
     }
 }
@@ -352,7 +380,7 @@ impl Mul for Value {
             (Matrix(x), Matrix(y)) => Ok(Matrix((x * y)?.into())),
             (Matrix(x), r) => Ok(Matrix(x.scale(r)?.into())),
             (l, Matrix(y)) => Ok(Matrix(y.scale(l)?.into())),
-			(l, r) => Err(Error::Multiply(l, r).into())
+            (l, r) => error!("cannot multiply: {l:?} * {r:?}")
 		}
 	}
 }
@@ -362,13 +390,13 @@ impl Div for Value {
 	fn div(self, rhs: Value) -> Self::Output {
 		use Value::*;
 		match promote(self, rhs) {
-            (Int(_), Int(0)) => Err(Error::DivideByZero.into()),
+            (Int(_), Int(0)) => error!("cannot divide by zero"),
 			(Int(x), Int(y)) => Ok(Ratio(Rational64::new(x, y))),
 			(Float(x), Float(y)) => Ok(Float(x / y)),
 			(Ratio(x), Ratio(y)) => Ok(Ratio(x / y)),
 			(Complex(x), Complex(y)) => Ok(Complex(x / y)),
-			(l, r) => Err(Error::Divide(l, r).into())
-		}
+            (l, r) => error!("cannot divide: {l:?} / {r:?}")
+        }
 	}
 }
 
@@ -378,7 +406,7 @@ impl BitOr for Value {
 		use Value::*;
 		match promote(self, rhs) {
 			(Int(x), Int(y)) => Ok(Int(x | y)),
-			(l, r) => Err(Error::Bitwise(l, r).into())
+            (l, r) => error!("cannot bitwise or: {l:?} | {r:?}")
 		}
 	}
 }
@@ -389,7 +417,7 @@ impl BitAnd for Value {
 		use Value::*;
 		match promote(self, rhs) {
 			(Int(x), Int(y)) => Ok(Int(x & y)),
-			(l, r) => Err(Error::Bitwise(l, r).into())
+            (l, r) => error!("cannot bitwise and: {l:?} & {r:?}")
 		}
 	}
 }
@@ -400,7 +428,7 @@ impl BitXor for Value {
 		use Value::*;
 		match promote(self, rhs) {
 			(Int(x), Int(y)) => Ok(Int(x ^ y)),
-			(l, r) => Err(Error::Bitwise(l, r).into())
+            (l, r) => error!("cannot bitwise xor: {l:?} ^ {r:?}")
 		}
 	}
 }
@@ -411,7 +439,7 @@ impl Shl for Value {
 		use Value::*;
 		match promote(self, rhs) {
 			(Int(x), Int(y)) => Ok(Int(x << y)),
-			(l, r) => Err(Error::Bitwise(l, r).into())
+            (l, r) => error!("cannot bitwise shift left: {l:?} << {r:?}")
 		}
 	}
 }
@@ -422,14 +450,14 @@ impl Shr for Value {
 		use Value::*;
 		match promote(self, rhs) {
 			(Int(x), Int(y)) => Ok(Int(x >> y)),
-			(l, r) => Err(Error::Bitwise(l, r).into())
+            (l, r) => error!("cannot bitwise shift right: {l:?} >> {r:?}")
 		}
 	}
 }
 
 fn ipow(n: i64, d: i64, p: i64) -> Result<(i64, i64)> {
 	Ok(match (n, d, p) {
-		(0, _, 0) => return Err(Error::ZeroExpZero.into()),
+		(0, _, 0) => return error!("cannot exponent: 0 ** 0"),
 		(0, _, _) => (0, 1),
 		(_, _, 0) => (1, 1),
 		(1, 1, _) => (1, 1),
@@ -447,7 +475,7 @@ impl Value {
 			(Float(x), Float(y)) => Ok(Float(x % y)),
 			(Ratio(x), Ratio(y)) => Ok(Ratio(x % y)),
 			(Complex(x), Complex(y)) => Ok(Complex(x % y)),
-			(l, r) => Err(Error::Modulo(r, l).into())
+            (l, r) => error!("cannot modulo: {l:?} % {r:?}")
 		}
 	}
 
@@ -461,7 +489,7 @@ impl Value {
 			(Float(x), Float(y)) => Ok(Float(x.powf(y))),
 			(Ratio(x), Ratio(y)) => Ok(Float(ratio_to_f64(x).powf(ratio_to_f64(y)))),
 			(Complex(x), Complex(y)) => Ok(Complex(x.powc(y))),
-			(l, r) => Err(Error::Exponent(l, r).into())
+            (l, r) => error!("cannot exponent: {l:?} ** {r:?}")
 		}
 	}
 
@@ -534,7 +562,7 @@ impl PartialOrd for Value {
 impl Value {
     pub fn val_cmp(&self, other: &Self) -> Result<Ordering> {
 		self.partial_cmp(other)
-            .map_or_else(|| Err(Error::Compare(self.clone(), other.clone()).into()), Ok)
+            .map_or_else(|| error!("cannot compare: {self:?} and {other:?}"), Ok)
 	}
 
     fn index_single(&self, index: &Value) -> Result<Self> {
@@ -545,17 +573,17 @@ impl Value {
             },
             (V::List(l), V::Int(i)) => {
                 if *i < 0 || *i as usize >= l.len() {
-                    return Err(Error::IndexOutOfBounds(*i, l.len()).into())
+                    return error!("{i} out of bounds for {self:?}")
                 }
                 Ok(l[*i as usize].clone())
             },
             (V::Matrix(m), V::Int(i)) => {
                 if *i < 0 || *i as usize >= m.values.len() {
-                    return Err(Error::MatrixIndexOutOfBounds(*i, m.domain, m.codomain).into())
+                    return error!("{i} out of bounds for {self:?}")
                 }
                 Ok(m.values[*i as usize].clone())
             },
-            _ => return Err(self::Error::BadIndex(self.clone(), index.clone()).into())
+            _ => return error!("{index:?} cant index {self:?}")
         }
     }
 
@@ -579,7 +607,7 @@ impl Value {
                 Ok(V::Table(ret.into()))
             }
             V::Matrix(m) => {
-                let err = || Err(self::Error::BadIndex(self.clone(), V::List(indexes.clone().into())).into());
+                let err = || error!("{self:?} can be index by [Int] or [Int;Int]");
                 if indexes.len() != 2 {
                     return err()
                 }
@@ -612,7 +640,7 @@ impl Value {
                     _ => return err()
                 }
             }
-            _ => return Err(self::Error::CannotIndex(self.clone()).into())
+            _ => return error!("cannot index {self:?}")
         }
     }
 
@@ -628,26 +656,26 @@ impl Value {
 
     fn store_index_single(&mut self, index: &Value, store: Value) -> Result<()> {
         use Value as V;
-        let err = self.clone();
+        let err = format!("{self:?}");
         match (self, index) {
             (V::Table(t), index) => {
                 t.insert(index.clone(), store)
             },
             (V::List(l), V::Int(i)) => {
                 if *i < 0 || *i as usize >= l.len() {
-                    return Err(Error::IndexOutOfBounds(*i, l.len()).into())
+                    return error!("{i} out of bounds for {err}")
                 }
                 l[*i as usize] = store;
                 Ok(())
             },
             (V::Matrix(m), V::Int(i)) => {
                 if *i < 0 || *i as usize >= m.values.len() {
-                    return Err(Error::MatrixIndexOutOfBounds(*i, m.domain, m.codomain).into())
+                    return error!("{i} out of bounds for {err}")
                 }
                 m.values[*i as usize] = store;
                 Ok(())
             },
-            _ => return Err(self::Error::BadIndex(err, index.clone()).into())
+            _ => return error!("{index:?} cant index {err}")
         }
     }
 
@@ -666,7 +694,7 @@ impl Value {
                 }
                 Ok(())
             }
-            _ => return Err(self::Error::CannotIndex(self.clone()).into())
+            _ => return error!("cannot index {self:?}")
         }
     }
 
@@ -684,10 +712,10 @@ impl Value {
         use Value as V;
         match self {
             V::Table(t) => {
-                let key = V::String(Rc::new(ident.to_string()));
+                let key = V::String(Rc::from(ident));
                 Ok(t.insert(key, val)?)
             },
-            _ => return Err(self::Error::FieldAccess(self.clone()).into())
+            _ => return error!("cannot field access assign {self:?}")
         }
     }
 
@@ -695,10 +723,10 @@ impl Value {
         use Value as V;
         match self {
             V::Table(t) => {
-                let key = V::String(Rc::new(ident.to_string()));
+                let key = V::String(Rc::from(ident));
                 Ok(t.get(&key)?.unwrap_or(&V::Nil).clone())
             },
-            _ => return Err(self::Error::FieldAccess(self.clone()).into())
+            _ => return error!("cannot field access {self:?}")
         }
     }
 
@@ -722,6 +750,15 @@ impl Value {
             LessEquals => Ok(Self::Bool(lhs <= rhs)),
             GreaterThan => Ok(Self::Bool(lhs > rhs)),
             LessThan => Ok(Self::Bool(lhs < rhs)),
+            Range | RangeEq => {
+                let Value::Int(lhs) = lhs else {
+                    return error!("range can only take [Int]'s")
+                };
+                let Value::Int(rhs) = rhs else {
+                    return error!("range can only take [Int]'s")
+                };
+                Ok(Self::Range(Rc::new((lhs, rhs, op == RangeEq))))
+            },
         }
     }
 
@@ -754,24 +791,75 @@ impl Not for Value {
     type Output = bool;
 
     fn not(self) -> Self::Output {
-        use Value::*;
+        use Value as V;
         match self {
-            Nil => true,
-            Bool(b) => !b,
-            Int(i) => i == 0,
-            Float(f) => f == 0.0,
-            Ratio(r) => *(r.numer()) == 0 || *(r.denom()) == 0,
-            Complex(c) => !c.is_normal(),
-            Regex(_) => false,
-            List(_) => false,
-            Matrix(_) => false,
-            Table(_) => false,
-            String(s) => s.as_str() == "",
-            Function(_) => false,
+            V::Nil => true,
+            V::Bool(b) => !b,
+            V::Int(i) => i == 0,
+            V::Float(f) => f == 0.0,
+            V::Ratio(r) => *(r.numer()) == 0 || *(r.denom()) == 0,
+            V::Complex(c) => !c.is_normal(),
+            V::Regex(_) => false,
+            V::List(_) => false,
+            V::Matrix(_) => false,
+            V::Table(_) => false,
+            V::String(s) => s.as_ref() == "",
+            V::Function(_) => false,
+            V::Iter(_) => false,
+            V::Range(_) => false,
+            V::File(_) => false,
+            V::Error(_) => false,
         }
     }
 }
 
+impl Value {
+
+    pub fn into_iter_fn(self) -> Result<Rc<Function>> {
+        let Value::Iter(iter) = self.into_iter()? else {
+            return error!("bypassed iter check")
+        };
+        Ok(iter)
+    }
+
+    pub fn into_iter(self) -> Result<Self> {
+        use Value as V;
+        Ok(match self {
+            V::Iter(..) => self,
+            V::List(l) => {
+                let iter = RefCell::new(l.into_inner().into_iter());
+                iter!(move |_,_| {
+                    match iter.borrow_mut().next() {
+                        Some(v) => Ok(v),
+                        None => Ok(V::Nil),
+                    }
+                })
+            },
+            V::Range(r) => {
+                let r = (*r).clone();
+                let lhs = RefCell::new(r.0);
+                let rhs = r.1;
+                iter!(move |_,_| {
+                    let val = *lhs.borrow();
+                    let next = *lhs.borrow() + 1;
+                    if (!r.2 && *lhs.borrow() < rhs) || (r.2 && *lhs.borrow() <= rhs) {
+                        *lhs.borrow_mut() = next;
+                        return Ok(Value::Int(val))
+                    }
+                    Ok(Value::Nil)
+                })
+            },
+            V::Function(f) => {
+                if f.arity > 0 || f.variadic {
+                    return error!("iterator functions cannot be varadic or take arguments")
+                }
+                V::Iter(f)
+            },
+            val => return error!("cannot turn {val:?} into an iterator")
+        })
+    }
+}
+
 fn dot(lhs: Vec<&Value>, rhs: Vec<&Value>) -> Result<Value> {
     let len = lhs.len();
 
@@ -830,9 +918,9 @@ impl Matrix {
 
     pub fn get(&self, row: usize, col: usize) -> Result<Value> {
         if row >= self.codomain || col >= self.domain {
-            return Err(self::Error::MatrixOutOfBounds(row, col, self.domain, self.codomain).into())
+            return error!("[{};{}] out of bounds for [Matrix {}x{}]", row, col, self.domain, self.codomain)
         }
-        let idx = col + row * self.codomain;
+        let idx = col + row * self.domain;
         Ok(self.values[idx].clone())
     }
 
@@ -840,9 +928,9 @@ impl Matrix {
 
     pub fn set(&mut self, row: usize, col: usize, val: Value) -> Result<()> {
         if row >= self.codomain || col >= self.domain {
-            return Err(self::Error::MatrixOutOfBounds(row, col, self.domain, self.codomain).into())
+            return error!("[{};{}] out of bounds for [Matrix {}x{}]", row, col, self.domain, self.codomain)
         }
-        let idx = col + row * self.codomain;
+        let idx = col + row * self.domain;
         self.values[idx] = val;
         Ok(())
     }
@@ -863,8 +951,8 @@ impl Matrix {
 
     // SPLCIE DOMAIN
     pub fn splice_cols(&self, col_start: usize, col_end: usize) -> Result<Self> {
-        if col_start <= col_end {
-            return Err(self::Error::MatrixInvSlice(col_start, col_end).into());
+        if col_start <= col_end  || col_end > self.domain {
+            return error!("[_;{}..{}] invalid for [Matrix {}x{}]", col_start, col_end, self.domain, self.codomain)
         }
 
         let mut cols = Vec::new();
@@ -890,8 +978,8 @@ impl Matrix {
 
     // SPLICE CODOMAIN
     pub fn splice_rows(&self, row_start: usize, row_end: usize) -> Result<Self> {
-        if row_start <= row_end {
-            return Err(self::Error::MatrixInvSlice(row_start, row_end).into());
+        if row_start <= row_end || row_end > self.codomain {
+            return error!("[{}..{};_] invalid for [Matrix {}x{}]", row_start, row_end, self.domain, self.codomain)
         }
 
         let mut rows = Vec::new();
@@ -915,12 +1003,64 @@ impl Matrix {
         Ok(res)
     }
 
+    pub fn increment(&self, increment: Value) -> Result<Self> {
+        let values = self.values.iter()
+            .map(|v| v.clone() + increment.clone())
+            .collect::<Result<Vec<Value>>>()?;
+        Ok(Matrix::new(self.domain, self.codomain, values))
+    }
+
+    pub fn decrement(&self, decrement: Value) -> Result<Self> {
+        let values = self.values.iter()
+            .map(|v| v.clone() - decrement.clone())
+            .collect::<Result<Vec<Value>>>()?;
+        Ok(Matrix::new(self.domain, self.codomain, values))
+    }
+
     pub fn scale(&self, scale: Value) -> Result<Self> {
         let values = self.values.iter()
             .map(|v| v.clone() * scale.clone())
             .collect::<Result<Vec<Value>>>()?;
         Ok(Matrix::new(self.domain, self.codomain, values))
     }
+
+    pub fn join_right(&self, other: &Matrix) -> Result<Self> {
+        if self.domain != other.domain || self.codomain != other.codomain {
+            return error!("matrix dimensions do not match");
+        }
+        let mut r1 = self.rows();
+        let mut r2 = other.rows();
+        let mut rows = Vec::new();
+        loop {
+            let Some(r1) = r1.next() else { break; };
+            let Some(r2) = r2.next() else { break; };
+
+            let mut row = r1
+                .into_iter()
+                .map(|v| v.clone())
+                .collect::<Vec<Value>>();
+
+            row.extend(r2.into_iter().map(|v| v.clone()));
+
+            rows.push(row);
+        }
+
+        let values = rows
+            .into_iter()
+            .reduce(|mut a,b| {a.extend(b); a})
+            .unwrap();
+
+        Ok(Matrix::new(self.domain * 2, self.codomain, values))
+    }
+
+    pub fn join_bottom(&self, other: &Matrix) -> Result<Self> {
+        if self.domain != other.domain || self.codomain != other.codomain {
+            return error!("matrix dimensions do not match");
+        }
+        let mut values = self.values.clone();
+        values.extend(other.values.clone());
+        Ok(Matrix::new(self.domain, self.codomain * 2, values))
+    }
 }
 
 impl Debug for Matrix {
@@ -950,7 +1090,9 @@ impl Add for Matrix {
 
     fn add(self, rhs: Self) -> Self::Output {
         if self.domain != rhs.domain || self.codomain != rhs.codomain {
-            return Err(self::Error::MatrixAdd(self.domain, self.codomain, rhs.domain, rhs.codomain).into())
+            return error!("cannot add: [Matrix {}x{}] + [Matrix {}x{}]",
+                          self.domain, self.codomain,
+                          rhs.domain, rhs.codomain)
         }
         let mut res = Matrix::empty(self.domain, self.codomain);
         for col in 0..self.domain {
@@ -968,7 +1110,9 @@ impl Sub for Matrix {
 
     fn sub(self, rhs: Self) -> Self::Output {
         if self.domain != rhs.domain || self.codomain != rhs.codomain {
-            return Err(self::Error::MatrixAdd(self.domain, self.codomain, rhs.domain, rhs.codomain).into())
+            return error!("cannot sub: [Matrix {}x{}] - [Matrix {}x{}]",
+                          self.domain, self.codomain,
+                          rhs.domain, rhs.codomain)
         }
         let mut res = Matrix::empty(self.domain, self.codomain);
         for col in 0..self.domain {
@@ -986,7 +1130,9 @@ impl Mul for Matrix {
 
     fn mul(self, rhs: Self) -> Self::Output {
         if self.domain != rhs.codomain {
-            return Err(self::Error::MatrixMultiply(self.domain, rhs.codomain).into())
+            return error!("cannot multiply: [Matrix {}x{}] * [Matrix {}x{}]",
+                          self.domain, self.codomain,
+                          rhs.domain, rhs.codomain)
         }
         let mut res = Self::empty(rhs.domain, self.codomain);
         for (i, row) in self.rows().enumerate() {
diff --git a/matrix/src/vm.rs b/matrix/src/vm.rs
index fec34b5..f98dc72 100644
--- a/matrix/src/vm.rs
+++ b/matrix/src/vm.rs
@@ -1,12 +1,11 @@
 use std::{rc::Rc, fmt::{Debug, Display}, usize, ops::{Index, IndexMut}, collections::HashMap, cell::RefCell, sync::{atomic::{AtomicUsize, Ordering}, Arc}};
-use crate::{value::{Value, self, ValueMap, Matrix}, gc::Gc, chunk::{Function, Instruction, Chunk, InnerFunction}, Result, compiler::NamesTable};
+use crate::{value::{Value, self, ValueMap, Matrix}, Result, gc::Gc, chunk::{Function, Instruction, Chunk, InnerFunction}, compiler::NamesTable, native};
 
 #[derive(Debug)]
 pub enum Error {
     ValueError(value::Error),
     NotFunction(Value),
     InvArity(usize, usize, Rc<str>),
-    UndefinedGlobal(Rc<str>),
     ExecNative,
 }
 
@@ -19,7 +18,6 @@ impl Display for Error {
             ValueError(err) => write!(f, "{err}"),
             NotFunction(v) => write!(f, "{v:?} is not a function"),
             InvArity(wanted, had, name) => write!(f, "function {name} takes {wanted} params but was given {had}"),
-            UndefinedGlobal(name) => write!(f, "{name} is not defined"),
             ExecNative => write!(f, "cannot execute a native function"),
         }
     }
@@ -89,21 +87,64 @@ impl<T> Index<usize> for Stack<T> {
     }
 }
 
-struct StackFrame {
+#[derive(Clone)]
+pub struct StackFrame {
     #[allow(dead_code)]
     name: Rc<str>,
     body: Rc<Chunk>,
     ip: usize,
     bp: usize,
+    lp: usize,
+    depth: usize,
 }
 
+struct VmError {
+    err: crate::Error,
+    frames: Vec<StackFrame>
+}
+
+impl From<crate::Error> for VmError {
+    fn from(err: crate::Error) -> Self {
+        VmError {
+            err,
+            frames: Vec::new()
+        }
+    }
+}
+
+impl From<self::Error> for VmError {
+    fn from(err: self::Error) -> Self {
+        VmError {
+            err: err.into(),
+            frames: Vec::new()
+        }
+    }
+}
+
+type VmResult<T> = std::result::Result<T, VmError>;
+
 impl StackFrame {
-    fn new(vm: &Vm, name: Rc<str>, body: Rc<Chunk>, arity: usize) -> Self {
+    fn new(vm: &Vm, name: Rc<str>, body: Rc<Chunk>, arity: usize, depth: usize) -> Self {
         Self {
             name,
             body,
             bp: vm.stack.len() - arity,
+            lp: vm.locals.len(),
             ip: 0,
+            depth
+        }
+    }
+}
+
+impl Default for StackFrame {
+    fn default() -> Self {
+        StackFrame {
+            name: Rc::from("<root>"),
+            body: Rc::new(Chunk::default()),
+            bp: 0,
+            lp: 0,
+            ip: 0,
+            depth: 0
         }
     }
 }
@@ -112,10 +153,17 @@ pub enum Interupt {
     KeyboardInterupt = 1
 }
 
+struct TryScope {
+    stack_len: usize,
+    locals_len: usize,
+    frame_depth: usize,
+    err_idx: usize,
+}
+
 pub struct Vm {
     stack: Stack<Value>,
     locals: Stack<Value>,
-    frames: Vec<StackFrame>,
+    trystack: Vec<TryScope>,
     globals: HashMap<u16, Value>,
     names: NamesTable,
     global_names: NamesTable,
@@ -132,6 +180,10 @@ impl Vm {
         self.stack.pop()
     }
 
+    fn top(&mut self) -> Value {
+        self.stack[self.stack.len() - 1].clone()
+    }
+
     pub fn names(&self) -> NamesTable {
         self.names.clone()
     }
@@ -148,7 +200,7 @@ impl Vm {
         Self {
             stack: Stack::new(),
             locals: Stack::new(),
-            frames: Vec::new(),
+            trystack: Vec::new(),
             globals: HashMap::new(),
             names: Rc::new(RefCell::new(Vec::new())),
             global_names: Rc::new(RefCell::new(Vec::new())),
@@ -156,10 +208,14 @@ impl Vm {
         }
     }
 
-    pub fn load_native_fn(&mut self, fun: Rc<Function>) {
+    pub fn load_global(&mut self, value: Value, name: &str) {
         let idx = self.global_names.borrow().len();
-        self.global_names.borrow_mut().push(fun.name.clone());
-        self.globals.insert(idx as u16, Value::Function(fun));
+        self.global_names.borrow_mut().push(name.into());
+        self.globals.insert(idx as u16, value);
+    }
+
+    pub fn load_global_fn(&mut self, value: Rc<Function>, name: &str) {
+        self.load_global(Value::Function(value), name)
     }
 
     fn init_frame(&mut self, fun: Rc<Function>) -> Result<StackFrame> {
@@ -170,7 +226,8 @@ impl Vm {
             self,
             fun.name.clone(),
             compiled_chunk.clone(),
-            fun.arity
+            fun.arity,
+            0
         ))
     }
 
@@ -178,162 +235,252 @@ impl Vm {
         self.interupt.load(Ordering::Relaxed) != 0
     }
 
-    pub fn run(&mut self, fun: Rc<Function>) -> Result<Value> {
-        let mut frame = self.init_frame(fun)?;
-        self.interupt.store(0, Ordering::SeqCst);
-        self.stack = Stack::new();
-        self.locals = Stack::new();
+    fn exec_ins(&mut self, frame: &mut StackFrame, ins: Instruction) -> VmResult<Option<Value>> {
+        use Instruction as I;
+        match ins {
+            I::NoOp => {},
+            I::CreateLocal => self.locals.push(self.stack.pop()),
+            I::LoadLocal(idx) => {self.stack.push(self.locals[idx as usize].clone());},
+            I::StoreLocal(idx) => self.locals[frame.bp + idx as usize] = self.pop(),
+            I::DiscardLocals(count) => {self.locals.truncate(self.locals.len() - count as usize)},
+            I::LoadGlobal(idx) => {
+                let val = self.globals
+                    .get(&idx)
+                    .unwrap()
+                    .clone();
+                self.stack.push(val);
+            },
+            I::StoreGlobal(idx) => {
+                let val = self.pop();
+                self.globals.insert(idx, val);
+            },
+            I::Const(idx) => self.push(frame.body.constants[idx as usize].clone()),
+            I::Int(i) => self.push(Value::Int(i as i64)),
+            I::True => self.push(Value::Bool(true)),
+            I::False => self.push(Value::Bool(false)),
+            I::Nil => self.push(Value::Nil),
+            I::Dup => self.push(self.stack[self.stack.len() - 1].clone()),
+            I::Discard(count) => {self.stack.truncate(self.stack.len() - count as usize)},
+            I::UnaryOp(op) => {
+                let val = self.pop();
+                self.push(Value::unary_op(op, val));
+            },
+            I::BinaryOp(op) => {
+                let rhs = self.pop();
+                let lhs = self.pop();
+                self.push(Value::binary_op(op, lhs, rhs)?);
+            },
+            I::NewList(items) => {
+                let list = self.stack.split_off(self.stack.len() - items as usize);
+                self.push(Value::List(list.inner.into()));
+            },
+            I::NewTable(items) => {
+                let mut table = ValueMap::new();
+                for _ in 0..items {
+                    let value = self.pop();
+                    let key = self.pop();
+                    table.insert(key, value)?;
+                }
+                self.push(Value::Table(table.into()))
+            },
+            I::NewMatrix(items, domain) => {
+                let values = self.stack.split_off(self.stack.len() - items as usize).inner;
+                let domain = domain as usize;
+                let codomain = values.len() / domain;
+                self.push(Value::Matrix(Gc::new(Matrix::new(domain, codomain, values))));
+            }
+            I::Jump(idx) => {
+                if self.check_interupt() {
+                    return Ok(Some(Value::Nil))
+                }
+                frame.ip = idx as usize;
+            }
+            I::JumpTrue(idx) => {
+                if self.check_interupt() {
+                    return Ok(Some(Value::Nil))
+                }
+                if !!self.pop() {
+                    frame.ip = idx as usize;
+                }
+            },
+            I::JumpFalse(idx) => {
+                if self.check_interupt() {
+                    return Ok(Some(Value::Nil))
+                }
+                if !self.pop() {
+                    frame.ip = idx as usize;
+                }
+            },
+            I::JumpNil(idx) => {
+                if self.check_interupt() {
+                    return Ok(Some(Value::Nil))
+                }
+                if self.pop() == Value::Nil {
+                    frame.ip = idx as usize;
+                }
+            },
+            I::Call(arity) => {
+                let arity = arity as usize;
 
-        loop {
-            use Instruction::*;
-            let ins = frame.body.code[frame.ip].clone();
-            frame.ip += 1;
+                let fun = self.pop();
+                let Value::Function(fun) = fun else {
+                    return Err(Error::NotFunction(fun).into())
+                };
 
-            match ins {
-                NoOp => {},
-                CreateLocal => self.locals.push(self.stack.pop()),
-                LoadLocal(idx) => {self.stack.push(self.locals[idx as usize].clone());},
-                StoreLocal(idx) => self.locals[frame.bp + idx as usize] = self.pop(),
-                DiscardLocals(count) => {self.locals.truncate(self.locals.len() - count as usize)},
-                LoadGlobal(idx) => {
-                    let val = self.globals
-                        .get(&idx)
-                        .unwrap()
-                        .clone();
+                if !fun.variadic && arity > fun.arity {
+                    return Err(Error::InvArity(fun.arity, arity as usize, fun.name.clone()).into())
+                }
+
+                let mut params = self.stack.split_off(self.stack.len() - arity).inner;
+
+                if params.len() < fun.arity {
+                    let new_arity = fun.arity - arity;
+                    let val = native!("<partial>", new_arity, false, move |(vm, vm_frame), args| {
+                        let mut params = params.clone();
+                        params.extend(args);
+                        vm.exec_fn(vm_frame, fun.clone(), params).map_err(|e| e.err)
+                    });
                     self.stack.push(val);
-                },
-                StoreGlobal(idx) => {
-                    let val = self.pop();
-                    self.globals.insert(idx, val);
-                },
-                Const(idx) => self.push(frame.body.constants[idx as usize].clone()),
-                Int(i) => self.push(Value::Int(i as i64)),
-                True => self.push(Value::Bool(true)),
-                False => self.push(Value::Bool(false)),
-                Nil => self.push(Value::Nil),
-                Dup => self.push(self.stack[self.stack.len() - 1].clone()),
-                Discard(count) => {self.stack.truncate(self.stack.len() - count as usize)},
-                UnaryOp(op) => {
-                    let val = self.pop();
-                    self.push(Value::unary_op(op, val));
-                },
-                BinaryOp(op) => {
-                    let rhs = self.pop();
-                    let lhs = self.pop();
-                    self.push(Value::binary_op(op, lhs, rhs)?);
-                },
-                NewList(items) => {
-                    let list = self.stack.split_off(self.stack.len() - items as usize);
-                    self.push(Value::List(list.inner.into()));
-                },
-                NewTable(items) => {
-                    let mut table = ValueMap::new();
-                    for _ in 0..items {
-                        let value = self.pop();
-                        let key = self.pop();
-                        table.insert(key, value)?;
-                    }
-                    self.push(Value::Table(table.into()))
-                },
-                NewMatrix(items, domain) => {
-                    let values = self.stack.split_off(self.stack.len() - items as usize).inner;
-                    let domain = domain as usize;
-                    let codomain = values.len() / domain;
-                    self.push(Value::Matrix(Gc::new(Matrix::new(domain, codomain, values))));
+                    return Ok(None);
                 }
-                Jump(idx) => {
-                    if self.check_interupt() {
-                        return Ok(Value::Nil)
+
+                if fun.variadic {
+                    if arity == fun.arity {
+                        params.push(Value::List(vec![].into()));
+                    } else {
+                        let count = arity - fun.arity;
+                        let varadic_params = params.split_off(params.len() - count);
+                        params.push(Value::List(varadic_params.into()));
                     }
-                    frame.ip = idx as usize;
                 }
-                JumpTrue(idx) => {
-                    if self.check_interupt() {
-                        return Ok(Value::Nil)
-                    }
-                    if !!self.pop() {
-                        frame.ip = idx as usize;
-                    }
-                },
-                JumpFalse(idx) => {
-                    if self.check_interupt() {
-                        return Ok(Value::Nil)
-                    }
-                    if !self.pop() {
-                        frame.ip = idx as usize;
-                    }
-                },
-                Call(arity) => {
-                    let fun = self.pop();
-                    let Value::Function(fun) = fun else {
-                        return Err(Error::NotFunction(fun).into())
-                    };
-                    let arity = arity as usize;
-                    let normal_args = if fun.variadic { fun.arity - 1 } else { fun.arity };
-                    if (fun.variadic && arity < normal_args) || (!fun.variadic && arity != normal_args) {
-                        return Err(Error::InvArity(normal_args, arity as usize, fun.name.clone()).into())
-                    }
-                    if fun.variadic {
-                        if arity == normal_args {
-                            self.push(Value::List(vec![].into()));
-                        } else if arity > normal_args {
-                            let count = arity - normal_args;
-                            let varadic_params = self.stack.split_off(self.stack.len() - count).inner;
-                            self.push(Value::List(varadic_params.into()));
-                        }
-                    }
-                    let name = fun.name.clone();
-                    match &fun.fun {
-                        InnerFunction::Compiled(body) => {
-                            let new_frame = StackFrame::new(self, name, body.clone(), fun.arity);
-                            self.frames.push(frame);
-                            frame = new_frame;
-                        },
-                        InnerFunction::Native(native_fun) => {
-                            let params = self.stack.split_off(self.stack.len() - fun.arity).inner;
-                            let res = native_fun(self, params)?;
-                            self.stack.push(res);
+
+                let res = self.exec_fn(frame, fun, params)?;
+                self.push(res);
+            },
+            I::Return => {
+                if self.check_interupt() {
+                    return Ok(Some(Value::Nil))
+                }
+                let ret = self.pop();
+                self.stack.truncate(frame.bp);
+                self.locals.truncate(frame.lp);
+                return Ok(Some(ret))
+            },
+            I::Field(name_idx) => {
+                let expr = self.pop();
+                let name = self.names.borrow()[name_idx as usize].clone();
+                self.push(expr.field_access(&name)?);
+            },
+            I::StoreField(name_idx) => {
+                let mut expr = self.pop();
+                let value = self.pop();
+                let name = self.names.borrow()[name_idx as usize].clone();
+                expr.store_field_access(&name, value)?;
+            },
+            I::Index(count) => {
+                let index = self.stack.split_off(self.stack.len() - count as usize);
+                let collection = self.pop();
+                let value = collection.index(&index.inner)?;
+                self.stack.push(value);
+            },
+            I::StoreIndex(count) => {
+                let index = self.stack.split_off(self.stack.len() - count as usize);
+                let mut collection = self.pop();
+                let value = self.pop();
+                collection.store_index(&index.inner, value)?;
+            },
+            I::IterCreate => {
+                let val = self.pop().into_iter();
+                self.push(val?);
+            },
+            I::IterNext => {
+                let Value::Iter(iter) = self.top() else { panic!("bypassed iter check"); };
+                let val = self.exec_fn(frame, iter, vec![])?;
+                self.push(val);
+            },
+            I::Try(idx) => {
+                let scope = TryScope {
+                    err_idx: idx as usize,
+                    frame_depth: frame.depth,
+                    stack_len: self.stack.len(),
+                    locals_len: self.locals.len(),
+                };
+                self.trystack.push(scope);
+            },
+            I::TryEnd => {
+                self.trystack.pop().unwrap();
+            },
+        };
+
+        Ok(None)
+    }
+
+    fn stack_trace(&mut self, frames: Vec<StackFrame>) -> String {
+        let mut trace = String::from("\x1b[33m\x1b[1mStack Trace:\x1b[0m\n");
+        for frame in frames {
+            let ip = frame.ip - 1;
+            let pos = frame.body.pos[ip];
+            trace.push_str(&format!("  {} at {}:{}\n", &frame.name, pos.row, pos.col));
+        }
+        trace
+    }
+
+    fn exec_fn(&mut self, frame: &mut StackFrame, fun: Rc<Function>, params: Vec<Value>) -> VmResult<Value> {
+        let name = fun.name.clone();
+        let params_len = params.len();
+        match &fun.fun {
+            InnerFunction::Compiled(body) => {
+                for param in params {
+                    self.stack.push(param);
+                }
+                let mut new_frame = StackFrame::new(self, name, body.clone(), params_len, frame.depth + 1);
+                self.exec(&mut new_frame)
+            },
+            InnerFunction::Native(native_fun) => {
+                Ok(native_fun((self, frame), params)?)
+            }
+        }
+    }
+
+    fn exec(&mut self, frame: &mut StackFrame) -> VmResult<Value> {
+        loop {
+            let ins = frame.body.code[frame.ip].clone();
+            frame.ip += 1;
+            match self.exec_ins(frame, ins) {
+                Ok(Some(val)) => return Ok(val),
+                Ok(None) => {},
+                Err(err) => {
+                    if let Some(catch) = self.trystack.pop() {
+                        if frame.depth != catch.frame_depth {
+                            self.trystack.push(catch);
+                            return Err(err);
                         }
+                        self.stack.truncate(catch.stack_len);
+                        self.locals.truncate(catch.locals_len);
+                        frame.ip = catch.err_idx;
+                        self.stack.push(Value::Error(err.err));
+                    } else {
+                        let mut err = err;
+                        err.frames.push(frame.clone());
+                        return Err(err)
                     }
                 },
-                Return => {
-                    if self.check_interupt() {
-                        return Ok(Value::Nil)
-                    }
-                    let Some(prev_frame) = self.frames.pop() else {
-                        break;
-                    };
-                    let ret = self.pop();
-                    self.stack.truncate(frame.bp);
-                    self.locals.truncate(0);
-                    self.push(ret);
-                    frame = prev_frame;
-                },
-                Field(name_idx) => {
-                    let expr = self.pop();
-                    let name = self.names.borrow()[name_idx as usize].clone();
-                    self.push(expr.field_access(&name)?);
-                },
-                StoreField(name_idx) => {
-                    let mut expr = self.pop();
-                    let value = self.pop();
-                    let name = self.names.borrow()[name_idx as usize].clone();
-                    expr.store_field_access(&name, value)?;
-                },
-                Index(count) => {
-                    let index = self.stack.split_off(self.stack.len() - count as usize);
-                    let collection = self.pop();
-                    let value = collection.index(&index.inner)?;
-                    self.stack.push(value);
-                },
-                StoreIndex(count) => {
-                    let index = self.stack.split_off(self.stack.len() - count as usize);
-                    let mut collection = self.pop();
-                    let value = self.pop();
-                    collection.store_index(&index.inner, value)?;
-                }
             }
         }
-        Ok(self.pop())
+    }
+
+    pub fn run_fn(&mut self, frame: &mut StackFrame, fun: Rc<Function>, params: Vec<Value>) -> Result<Value> {
+        self.exec_fn(frame, fun, params).map_err(|e| e.err)
+    }
+
+    pub fn run(&mut self, fun: Rc<Function>) -> Result<Value> {
+        let mut frame = self.init_frame(fun)?;
+        self.interupt.store(0, Ordering::SeqCst);
+        self.stack = Stack::new();
+        self.locals = Stack::new();
+        self.exec(&mut frame).map_err(|e| {
+            let trace = self.stack_trace(e.frames);
+            (e.err, trace).into()
+        })
     }
 }