Cleaning up Ruby array in C extension.

test.c

#define RSTRING_EMPTY_P(s) (RSTRING_LEN(s) == 0)

static VALUE
magic_strip(VALUE v)
{
	return (ARRAY_P(v) || STRING_P(v)) ?	       \
		rb_funcall(v, rb_intern("strip"), 0) : \
		Qnil;
}

static VALUE
magic_strip_array(VALUE value) {
	VALUE array = rb_ary_new();
	VALUE entry = Qundef;

	for (int i = 0; i < RARRAY_LEN(value); i++) {
		entry = rb_ary_entry(value, i);
		if (NIL_P(entry))
			continue;
		if (STRING_P(entry)) {
			if (RSTRING_EMPTY_P(entry))
				continue;
			entry = magic_strip(entry);
		}
		rb_ary_push(array, entry);
	}

	return array;
}