Re: Idea: ifdef-like feature to ease userland BC

On 8 Mar 2014, at 23:01, Chris Wright <daverandom@php.net> wrote: > Imagine that some_func() is only ever used in the context of a > foreach. For BC reasons, we have to keep this API. Since 5.5, we could > use a generator (yes, we could use an iterator, I said it was > contrived :-P), but we need to provide BC with older PHP versions: > > function some_func() { > $fp = fopen('some_file.ext'); > #if PHP_VERSION >= 5.5.0 > while (false !== $line = fgets($fp)) { > yield $line; > } > #else > $result = array(); > while (false !== $line = fgets($fp)) { > $result[] = $line; > } > return $result; > #endif > } Ah, that’s a good example. > **However** the thought occurs that, while potentially useful, a > pre-processor of this nature could easily be done with a userland > implementation, a composer dependency and a composer > after-install/after-update script… Right. You could also just use include or require to load a file with a PHP 5.6 implementation or a PHP 5.5 implementation, conditionally, though for differences which are just a few lines, this would be inconvenient. -- Andrea Faulds http://ajf.me/