is_builtin
if (is_builtin(c))
if (is_builtin(c))
if (is_builtin(*dp)) {
if (is_builtin(*s)) {
#define is_alpha(x) (!is_builtin(x) && \
#define is_alnum(x) (!is_builtin(x) && \
#define is_space(x) (!is_builtin(x) && \
#define is_digit(x) (!is_builtin(x) && iswascii(x) && isdigit(x))
if (is_builtin(*s)) {