-bool lex_force_match (struct lexer *, enum token_type);
-bool lex_force_match_id (struct lexer *, const char *);
-bool lex_force_int (struct lexer *);
-bool lex_force_num (struct lexer *);
-bool lex_force_id (struct lexer *);
-bool lex_force_string (struct lexer *);
+bool lex_force_match (struct lexer *, enum token_type) WARN_UNUSED_RESULT;
+bool lex_force_match_id (struct lexer *, const char *) WARN_UNUSED_RESULT;
+bool lex_force_int (struct lexer *) WARN_UNUSED_RESULT;
+bool lex_force_int_range (struct lexer *, const char *name,
+ long min, long max) WARN_UNUSED_RESULT;
+bool lex_force_num (struct lexer *) WARN_UNUSED_RESULT;
+bool lex_force_num_range_closed (struct lexer *, const char *name,
+ double min, double max) WARN_UNUSED_RESULT;
+bool lex_force_num_range_halfopen (struct lexer *, const char *name,
+ double min, double max) WARN_UNUSED_RESULT;
+bool lex_force_num_range_open (struct lexer *, const char *name,
+ double min, double max) WARN_UNUSED_RESULT;
+bool lex_force_id (struct lexer *) WARN_UNUSED_RESULT;
+bool lex_force_string (struct lexer *) WARN_UNUSED_RESULT;
+bool lex_force_string_or_id (struct lexer *) WARN_UNUSED_RESULT;