1 files changed, 91 insertions, 86 deletions

diff --git a/matrix/src/lex.rs b/matrix-lang/src/lex.rs
index 8a07234..b2487ad 100644
--- a/matrix/src/lex.rs
+++ b/matrix-lang/src/lex.rs
@@ -1,6 +1,5 @@
-use std::{rc::Rc, fmt::Debug};
-use regex::Regex;
-use crate::Result;
+use std::fmt::{Debug, Display};
+use crate::prelude::*;
 
 pub struct RegexToken {
     regex: Regex
@@ -30,6 +29,36 @@ impl From<RegexToken> for Regex {
     }
 }
 
+#[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 }
+    }
+}
+
+impl Display for Position {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}:{}", self.row, self.col)
+    }
+}
+
+impl Display for TokenData {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{self:?}")
+    }
+}
+
+impl Display for Token {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.data)
+    }
+}
+
 #[derive(Debug, PartialEq)]
 pub enum TokenData {
     //syntax
@@ -106,6 +135,7 @@ pub enum TokenData {
     Else,
     While,
     Let,
+    Const,
     Function,
     True,
     False,
@@ -133,48 +163,6 @@ pub struct Token {
     pub blen: usize,
 }
 
-#[derive(Debug)]
-pub enum Error {
-    UnexpectedCharacter(char),
-    ExpectedChar(char, char),
-    InvalidCodepoint,
-    UnexpectedEof,
-    InvalidDigit(char),
-    InvalidStringEscape(char),
-    InvalidRegex(anyhow::Error),
-    InvalidNumber(String),
-}
-
-impl std::fmt::Display for Error {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        use Error::*;
-        match self {
-            UnexpectedCharacter(char) => write!(f, "Unexpected char: '{char}'"),
-            UnexpectedEof => write!(f, "Unexpected end of file"),
-            ExpectedChar(expected, got) => write!(f, "Expected char: '{expected}', instead got: '{got}'"),
-            InvalidCodepoint => write!(f, "Invalid codepoint"),
-            InvalidDigit(char) => write!(f, "Invalid digit: '{char}'"),
-            InvalidStringEscape(char) => write!(f, "Invalid string escape: '\\{char}"),
-            InvalidRegex(err) => write!(f, "{err}"),
-            InvalidNumber(num) => write!(f, "Invalid number: '{num}'")
-        }
-    }
-}
-
-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,
@@ -203,6 +191,12 @@ impl<T: Into<String>> From<T> for Lexer {
     }
 }
 
+macro_rules! error {
+    ($($arg:tt)*) => {
+        exception!(PARSE_EXCEPTION, $($arg)*)
+    };
+}
+
 impl Lexer {
     pub fn new<T: Into<String>>(input: T) -> Self {
         let data: Vec<char> = input.into().chars().collect();
@@ -239,7 +233,7 @@ impl Lexer {
     fn next_not_eof(&mut self) -> Result<char> {
         let c = self.next();
         if c == '\0' {
-            return Err(Error::UnexpectedEof.into())
+            return Err(error!("unexpected end of file"))
         }
         Ok(c)
     }
@@ -247,7 +241,7 @@ impl Lexer {
     fn next_expect(&mut self, expected: char) -> Result<char> {
         let c = self.next();
         if c != expected {
-            return Err(Error::ExpectedChar(expected, c).into())
+            return Err(error!("expected character '{c}'"))
         }
         Ok(c)
     }
@@ -259,7 +253,6 @@ impl Lexer {
     }
 
     fn lex_string(&mut self, delimit: char) -> Result<Rc<str>> {
-        use Error::*;
 
         let mut buf = String::new();
 
@@ -291,8 +284,8 @@ impl Lexer {
                     let n1 = self.next_not_eof()?;
                     let n2 = self.next_not_eof()?;
                     buf.push(char::from_u32(
-                        n1.to_digit(16).ok_or(InvalidDigit(n1))? * 16 +
-                        n2.to_digit(16).ok_or(InvalidDigit(n2))?
+                        n1.to_digit(16).ok_or(error!("invalid digit '{n1}'"))? * 16 +
+                        n2.to_digit(16).ok_or(error!("invalid digit '{n2}'"))?
                     ).unwrap());
                 },
                 'u' => {
@@ -302,15 +295,15 @@ impl Lexer {
                         let c = self.next_not_eof()?;
                         if c == '}' { break }
                         if n >= 0x1000_0000_u32 {
-                            return Err(InvalidCodepoint.into())
+                            return Err(error!("invalid utf8 codepoint '{n}'"))
                         }
-                        n = n * 16 + c.to_digit(16).ok_or::<crate::Error>(InvalidDigit(c).into())?;
+                        n = n * 16 + c.to_digit(16).ok_or(error!("invalid digit '{c}'"))?;
                     }
-                    let ch = char::from_u32(n).ok_or::<crate::Error>(InvalidCodepoint.into())?;
+                    let ch = char::from_u32(n).ok_or(error!("invalid codepoint '{n}'"))?;
                     buf.push(ch);
 
                 },
-                _ => return Err(InvalidStringEscape(next).into())
+                _ => return Err(error!("invalid string escape '\\{next}'"))
             }
         }
 
@@ -318,13 +311,12 @@ impl Lexer {
     }
 
     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(E::UnexpectedCharacter(initial).into())
+            return Err(error!("unexpected character '{initial}'"))
         }
 
         buf.push(initial);
@@ -342,6 +334,7 @@ impl Lexer {
             "else" => T::Else,
             "while" => T::While,
             "let" => T::Let,
+            "const" => T::Const,
             "fn" | "function" => T::Function,
             "true" => T::True,
             "false" => T::False,
@@ -364,7 +357,6 @@ impl Lexer {
 
     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;
@@ -375,7 +367,7 @@ impl Lexer {
                 n = n * radix + (i as i64);
                 char_found = true;
             } else if self.peek().is_ident() {
-                return Err(E::InvalidDigit(self.peek()).into())
+                return Err(error!("invalid digit '{}'", self.peek()))
             } else {
                 break;
             }
@@ -384,13 +376,11 @@ impl Lexer {
         if char_found {
             Ok(T::Int(n))
         } else {
-            Err(E::InvalidNumber(format!("0{radix_char}")).into())
+            Err(error!("invalid number radix specifier '0{radix_char}'"))
         }
     }
 
     fn lex_number(&mut self, initial: char) -> Result<TokenData> {
-        use Error as E;
-
         if initial == '0' {
             match self.peek() {
                 'x' => {
@@ -459,7 +449,7 @@ impl Lexer {
         }
 
         if self.peek().is_ident() {
-            return Err(E::UnexpectedCharacter(self.peek()).into())
+            return Err(error!("unexpected character '{}'", self.peek()))
         }
 
         if let Ok(int) = buf.parse::<i64>() {
@@ -478,23 +468,11 @@ impl Lexer {
             return Ok(T::Float(float))
         }
 
-        Err(E::InvalidNumber(buf).into())
+        Err(error!("invalid number '{buf}'"))
     }
 
-    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> {
+    fn read_token(&mut self, ignore_newlines: bool) -> Result<Token> {
         use TokenData as T;
-        use Error as E;
 
         self.skip_whitespace(ignore_newlines);
 
@@ -705,7 +683,7 @@ impl Lexer {
                         self.next();
                         T::Regex(regex::Regex::new(&self.lex_string(next)?)
                               .map(|e| e.into())
-                              .map_err(|e| E::InvalidRegex(e.into()))?)
+                              .map_err(|e| error!("invalid regex: '{e}'"))?)
                     }
                     _ => {
                         self.lex_ident(char)?
@@ -744,7 +722,6 @@ impl Lexer {
         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,
@@ -754,19 +731,47 @@ impl Lexer {
         })
     }
 
-    pub fn peek_token(&mut self) -> Result<Token> {
-        self.peek_token_impl(true)
+    pub fn next_token(&mut self) -> Result<Token> {
+        let pos = self.pos;
+        match self.read_token(true) {
+            Ok(token) => Ok(token),
+            Err(e) => Err(e.pos(pos)),
+        }
     }
 
-    pub fn next_token(&mut self) -> Result<Token> {
-        self.next_token_impl(true)
+    pub fn next_token_nl(&mut self) -> Result<Token> {
+        let pos = self.pos;
+        match self.read_token(false) {
+            Ok(token) => Ok(token),
+            Err(e) => Err(e.pos(pos)),
+        }
     }
 
-    pub fn peek_token_nl(&mut self) -> Result<Token> {
-        self.peek_token_impl(false)
+    pub fn peek_token(&mut self) -> Result<Token> {
+        let idx = self.index;
+        let pos = self.pos;
+        let bidx = self.byte_len;
+        let token = self.read_token(true);
+        self.index = idx;
+        self.pos = pos;
+        self.byte_len = bidx;
+        match token {
+            Ok(token) => Ok(token),
+            Err(e) => Err(e.pos(pos)),
+        }
     }
 
-    pub fn next_token_nl(&mut self) -> Result<Token> {
-        self.next_token_impl(false)
+    pub fn peek_token_nl(&mut self) -> Result<Token> {
+        let idx = self.index;
+        let pos = self.pos;
+        let bidx = self.byte_len;
+        let token = self.read_token(false);
+        self.index = idx;
+        self.pos = pos;
+        self.byte_len = bidx;
+        match token {
+            Ok(token) => Ok(token),
+            Err(e) => Err(e.pos(pos)),
+        }
     }
 }