current community

more stack exchange communities

Stack Exchange
tour help
careers 2.0
Take the 2-minute tour ×
Stack Overflow is a question and answer site for professional and enthusiast programmers. It's 100% free, no registration required.
up vote 0 down vote favorite

I want to create a directory class, and I want it to function as an iterator (foreach-able). But I want it to be generator based (for example a function that does "yield"). Is it possible?

share|improve this question
add comment

2 Answers

up vote 2 down vote accepted

There is not an interface explicitly for classes to implement generators, but you can make use of IteratorAggregate here.

See this example of implementing IteratorAggregate from the Generators RFC

class Test implements IteratorAggregate {
    protected $data;

    public function __construct(array $data) {
        $this->data = $data;
    }

    public function getIterator() {
        foreach ($this->data as $key => $value) {
            yield $key => $value;
        }
        // or whatever other traversation logic the class has
    }
}

$test = new Test(['foo' => 'bar', 'bar' => 'foo']);
foreach ($test as $k => $v) {
    echo $k, ' => ', $v, "\n";
}
share|improve this answer
 
thank you very much :) –  user1735111 Feb 23 '13 at 17:15
add comment
up vote 0 down vote

Generators are Iterators.

From http://www.php.net/manual/en/language.generators.object.php

When a generator function is called for the first time, an object of the internal Generator class is returned. This object implements the Iterator interface in much the same way as a forward-only iterator object would.

share|improve this answer
 
But they will be introduced in 5.5 –  Darhazer Feb 23 '13 at 16:12
 
Yes. The question referred to"yield", so I assumed it was about PHP 5.5 –  fab Feb 23 '13 at 16:15
 
you are right, but i should have been more accurate –  user1735111 Feb 23 '13 at 17:20
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.