better

1 files changed, 31 insertions, 1 deletions

diff --git a/masm/lex.c b/masm/lex.c
index 788523b..37adf8e 100644
--- a/masm/lex.c
+++ b/masm/lex.c
@@ -149,6 +149,14 @@ static int lex_number(struct lexer *lexer, int64_t *n)
 {
 	int64_t number = 0;
 	int base = 10;
+	int neg = 0;
+
+	// check if negative
+	if (lex_peek(lexer) == '-') {
+		lex_next(lexer);
+		neg = 1;
+	}
+
 
 	// skip all leading zeros, they dont do anything.
 	// this also allows us to directly check for 0b, 0o, and 0x
@@ -200,6 +208,9 @@ static int lex_number(struct lexer *lexer, int64_t *n)
 		number += n;
 	}
 
+	if (neg)
+		number = -number;
+
 	*n = number;
 	return M_SUCCESS;
 }
@@ -226,7 +237,8 @@ again: // use label to avoid whitespace recursion
 	case ';':
 	case '#':
 		skip_comment(lexer);
-		goto again;
+		token->type = TOK_NL;
+		break;
 	case ' ':
 	case '\t':
 		// skip white space
@@ -267,6 +279,7 @@ again: // use label to avoid whitespace recursion
 		lex_next(lexer);
 		res = lex_string(lexer, token->text);
 		break;
+	case '-':
 	case '0':
 	case '1':
 	case '2':
@@ -341,3 +354,20 @@ char *token_str(enum token_type type)
         }
 	return "unknown";
 }
+
+void lexer_save(struct lexer *lexer, struct lexer_state *state)
+{
+	state->x = lexer->x;
+	state->y = lexer->y;
+	state->peek = lexer->peek;
+	state->offset = ftell(lexer->file);
+}
+
+/* load a different state into a lexer */
+void lexer_load(struct lexer *lexer, const struct lexer_state *state)
+{
+	lexer->x = state->x;
+	lexer->y = state->y;
+	lexer->peek = state->peek;
+	fseek(lexer->file, state->offset, SEEK_SET);
+}