On 8/12/12 5:33 PM, Levi Morrison wrote:
On Sun, Aug 12, 2012 at 2:08 PM, Brian Moon <br...@moonspot.net> wrote:
Do you have a good example usage other than a file? I don't find
fopen/fgets/fclose all that complicated. What are the other valid use cases for
such a thing?
One fabulous use case is creating an iterator for a Binary Search
Tree. A post order done without generators looks like:
https://github.com/morrisonlevi/PHP-Datastructures/blob/master/src/Spl/PostOrderIterator.php.
An iterator using a generator looks something like:
public function getIterator() {
if ($this->left) yield* $this->left;
yield $this->value;
if ($this->right) yield* $this->right;
}
This is 5 lines. The fully commented version of the post-order
iterator previously mentioned is 106 lines of code and is considerably
harder to understand.
Well, it's 52 lines, not 106. The 5 lines above are not commented nor
are they spaced at all like the ones in the class. In the above example,
what sets $this->right? or $this->left? There has to be more calling
code around this. I don't consider this a very good example.
Brian.
brianlm...@php.net
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