get_next_token returns result which includes possible error and token

include/lexer/lexer.h

@@ -10,7 +10,7 @@
 typedef const char *str_view_t;
 
 typedef enum {
-	TK_NO_TOKEN,
+  TK_NO_TOKEN,
   TK_L_BRACE,
   TK_R_BRACE,
   TK_L_BRACKET,
@@ -22,7 +22,7 @@ typedef enum {
   TK_STR_VAL,
   TK_INTEGER,
   TK_DOUBLE,
-} token_type_t;
+} token_type;
 
 typedef union {
   void *no_val;
@@ -34,15 +34,30 @@ typedef union {
 typedef struct {
   u64 line;
   u64 column;
-  token_type_t type;
+  token_type type;
   token_value_t value;
 } token_t;
 
+typedef enum {
+  LEX_ERR_NONE,
+  LEX_ERR_INVALID,
+} lex_err_type;
+
+typedef struct {
+  lex_err_type errno;
+  str_view_t msg;
+} lex_err_t;
+
+typedef struct {
+  lex_err_t error;
+  token_t token;
+} lex_result_t;
+
 typedef struct lexer lexer_t;
 
 void lexer_init(lexer_t **lexer);
 void lexer_free(lexer_t **lexer);
-token_t get_next_token(lexer_t *lexer, const char *text);
+lex_result_t get_next_token(lexer_t *lexer, const char *text);
 
 bool validate_json(char *json);
 void print_token(token_t token);