Re: Thoughts on C version supported for PHP-Next

发自我的 iPad > 在 2014年7月28日，22:20，Andrea Faulds <ajf@ajf.me> 写道： > > > On 28 Jul 2014, at 15:00, Derick Rethans <derick@php.net> wrote: > >>> Well, we don’t need to allow all of C99. We can simply allow using >>> features that are widely supported and actually useful. For example, >>> declarations between statements, >> >> I think that makes code a lot less readable, so I would not be in favour >> allowing this in our coding guidelines. > > Really? I’ve found that declaring everything in advance makes for hard-to-read code. To take > an example from code I’ve written (admittedly not C code - GML if anyone’s curious - but it > might as well be), the first line of a function looked like this: > > var list, hashList, text, i, pluginname, pluginhash, realhash, url, handle, filesize, > progress, tempfile, tempdir, failed, lastContact, isCached, env; > > Even broken onto multiple lines, declaring everything at once isn’t nice. For large functions > (and some functions have to be large necessarily), declaring everything at the start just means a > long list of variables and I would argue impairs code readability. > > You should declare variables when and where you need them. If everything is done at the top, > you have to scroll up to check the type of a variable. It also means that now-unused variables are > less obvious as the declarations are far away from the usage, so you probably won’t spot that > it’s useless unless you look at your compiler warnings. > > Actually, a similar issue popped up in the code where that example was from. The language it > was written in had some unfortunate properties, one of which was that variables not explicitly > declared would instead be treated as properties of the current object. Because all the variables > were declared at the start of the function, it was easy to miss the fact that some variables being > used had not actually been declared. Of course this specific issue doesn’t exist in C, but it is > an example of why having to declare all your variables at the start of a function isn’t really a > good thing. > > If nothing else, I think we should use C99’s ability to declare variables between statements. > It makes it more likely mistakes will be spotted, eases reading code, and as far as I am aware, is > widely supported. I really hate this. Thanks > > -- > Andrea Faulds > http://ajf.me/ > > > > > > -- > PHP Internals - PHP Runtime Development Mailing List > To unsubscribe, visit: http://www.php.net/unsub.php >