-bool is_space(char c) {
- return (c == ' ') || (c == '\t');
-}
-
-bool is_number(char c) {
- return ('0' <= c) && (c <= '9');
-}
-
-bool is_alpha(char c) {
- return (c == '_') || (('a' <= c) && (c <= 'z')) || (('A' <= c) && (c <= 'Z'));
-}
-
-bool is_alpha_num(c) {
- return is_number(c) || is_alpha(c);
-}