start adding error message support

src/lexer/lex.l

@@ -108,8 +108,6 @@ int yywrap(void * unused_param) {
 #[^\n]*        { /* skip comment */ }
 
 .   {
-    GET_STATE
-    fprintf(stderr, "%s:%zu:%zu error: unexpected character '%s'\n", state->path, state->current_line+1, COLUMN_NO+1, yytext);
-    exit(1);
+    return TOKEN_INVALID;
 }
 %%

src/lexer/lexer.c

@@ -1,8 +1,8 @@
 #include "lexer.h"
-#include "lex.yy.h"
 #include "../string/string.h"
+#include "lex.yy.h"
 
-void lexer(LexerState state) {
+ArErr lexer(LexerState state) {
   size_t line = 1;
   size_t column = 1;
   int ch;
@@ -32,13 +32,16 @@ void lexer(LexerState state) {
 
   int token;
   while ((token = yylex(scanner)) != 0) {
-    Token token_struct = (Token){
-      token,
-      state.current_line+1,
-      state.current_column+1,
-      yyget_leng(scanner),
-      cloneString(yyget_text(scanner))
-    };
+    if (token == TOKEN_INVALID) {
+      ArErr err = create_err(state.current_line + 1, state.current_column + 1,
+                        yyget_leng(scanner), state.path, "Syntax Error",
+                        "Invalid Token '%s'", yyget_text(scanner));
+      yylex_destroy(scanner);
+      return err;
+    }
+    Token token_struct =
+        (Token){token, state.current_line + 1, state.current_column + 1,
+                yyget_leng(scanner), cloneString(yyget_text(scanner))};
     darray_push(state.tokens, &token_struct);
     if (token == TOKEN_NEW_LINE) {
       state.current_line += 1;
@@ -48,4 +51,5 @@ void lexer(LexerState state) {
     }
   }
   yylex_destroy(scanner);
+  return no_err;
 }

src/lexer/lexer.h

@@ -4,9 +4,10 @@
 #include "../dynamic_array/darray.h"
 #include "token.h"
 #include <stdio.h>
+#include "../err.h"
 
 typedef struct {
-  const char *path;
+  char *path;
   FILE *file;
   size_t current_line;
   size_t current_column;
@@ -14,6 +15,6 @@ typedef struct {
   // add more fields as needed
 } LexerState;
 
-void lexer(LexerState state);
+ArErr lexer(LexerState state);
 
 #endif // LEXER_H

src/lexer/token.h

@@ -72,6 +72,7 @@ typedef enum {
   TOKEN_COMMA,
   TOKEN_COLON,
   TOKEN_EXCLAMATION,
+  TOKEN_INVALID,
 } TokenType;
 
 typedef struct {