Question

Is there a way of doing array_map but as an iterator?

For example:

foreach (new MapIterator($array, $function) as $value)
{
   if ($value == $required)
      break;
}

The reason to do this is that $function is hard to calculate and $array has too many elements, only need to map until I find a specific value. array_map will calculate all values before I can search for the one I want.

I could implement the iterator myself, but I want to know if there is a native way of doing this. I couldn’t find anything searching PHP documentation.

Answer 1

In short: No.

There is no lazy iterator mapping built into PHP. There is a non-lazy function iterator_apply(), but nothing like what you are after.

You could write one yourself, as you said. I suggest you extend IteratorIterator and simply override the current() method.

If there were such a thing it would either be documented here or here.