Rename lexer string functions

include/lexer/lexer.h

@@ -17,9 +17,10 @@ typedef enum {
   TK_NULL,
   TK_TRUE,
   TK_FALSE,
-  TK_STRING_LITERAL,
-  TK_INTEGER_LITERAL,
-  TK_DOUBLE_LITERAL,
+  TK_STR_KEY,
+  TK_STR_VAL,
+  TK_INTEGER,
+  TK_DOUBLE,
 } token_type_t;
 
 typedef union {