size()
public
Returns the size of the enumerator, or
nil if it can’t be calculated lazily.
(1..100).to_a.permutation(4).size
loop.size
(1..100).drop_while.size
static VALUE
enumerator_size(VALUE obj)
{
struct enumerator *e = enumerator_ptr(obj);
int argc = 0;
const VALUE *argv = NULL;
VALUE size;
if (e->size_fn) {
return (*e->size_fn)(e->obj, e->args, obj);
}
if (e->args) {
argc = (int)RARRAY_LEN(e->args);
argv = RARRAY_CONST_PTR(e->args);
}
size = rb_check_funcall(e->size, id_call, argc, argv);
if (size != Qundef) return size;
return e->size;
}