minor implement lexer

include/globals.h

@@ -1,5 +1,6 @@
 #pragma once
 #include <stdint.h>
+#include <stddef.h>
 
 typedef enum {
     LBRACK,
@@ -21,15 +22,23 @@ typedef enum {
     NUM,
     STRING_LITERAL,
 
+    VAL,
     RETURN,
     IF,
     ELSE,
-    
+
+    EOF_TOKEN,
     ERROR
 } TokenType;
 
+typedef struct {
+    size_t len;
+    char* string;
+} TokenString;
+
 typedef struct {
     TokenType type;
-    char *data;
     uint32_t line;
+    TokenString data;
 } Token;
+