Adding enumerate

[ragboyjr]

Adding ability to enumerate over key-value tuples
of iterators

Signed-off-by: RJ Garcia rj@bighead.net

[ragboyjr]

@nikic any word?

[nikic]

Do you have any specific use case in mind for this function? I realize that this is a "standard" function, but I'm not sure if it's useful in a language that has a native concept of key-value pairs in iterators (the lack of which enumerate() works around in other languages).

[ragboyjr]

@nikic yes, I need to use it all the time when I need to map a set of items and use the key.

The issue is that iter\map doesn't send the key parameter in the mapping function.

For example:

$rows_from_db = $db->query();
$html_items = iter\map(function($tup) {
  list($index, $row) = $tup;
  return sprintf("<li class="%s">%s</li>", $index % 2 ? 'odd' : 'even', $row['name']);
}, iter\enumerate($rows_from_db));

The only other way to accomplish this through the library would be to use reduce the database rows and concatenate.

[nikic]

@ragboyjr That makes sense, thanks. Could you please add another test that shows enumerate() behavior on an array with (string) keys?

[ragboyjr]

@nikic sure, like that?

[nikic]

Merged as 95d877c. Thanks!

[ragboyjr]

Awesome thanks!