Re: [RFC] Return Type Declarations

> > As far as the order of keywords in a closure, what order does Hack use? >> >>> The rest of the syntax seems based on it, so it seems sensible to >>> follow >>> suit. (I couldn't find that information from 60 seconds on hacklang.org >>> , >>> but it may be there.) >>> >> >> >> At least in the 2.4 branch of HHVM (which I have installed) they put it >> before the use statement. Now that I have thought about this more, this is >> a poor decision: >> >> * use statements are basically parameters at construction time instead >> of >> runtime >> * putting the return type before the use statement looks really ugly >> >> I will attempt to contact the HHVM team (perhaps SaraG) to see if there >> was >> a technical reason for it. >> > > I would agree, and look forward to seeing their reasoning. HHVM puts the return type before the use case because: - A user is already familiar with function(): Foo - A use statement is not really part of the function signature (during inheritance and such) Additionally, it is common to write closures using their shorthand notation: ==> (see http://docs.hhvm.com/manual/en/hack.lambda.php) I would counter: - Use statements are special parameters (similar to constructor arguments) and that putting it after the use statement makes more sense - Putting it after use statements is less ugly. - Putting it before the use statement is a bit confusing; consider this Hack declaration: $i = 0; $inc = function(): Iterator<int> use(&$i) {//... It looks like the Iterator<int> is somehow using $i. What does this list think?