Re: Types on the right or on the left

> On 4 Nov 2014, at 11:50, Chris Wright <cw@daverandom.com> wrote: > > On 4 November 2014 10:32, Andrea Faulds <ajf@ajf.me> wrote: > > > I thought it was inconsistent, but after discussions on StackOverflow, I don't think > > it actually is. > Return types describe the return type of a function, not the type of a > > function. So there's no reason > they have to go before the function name like parameter > > types do. > > So, in a sentence: > > In PHP, input types go on the left and output types go on the right. > > This sounds like a convention that could be established and followed, and no-one could > reasonably call it inconsistent if it was adhered to. > That’s not quite what I meant, but I’d also agree with that convention. For parameters, the type is of the thing itself: function foo(Foo $foo, Bar $bar); Here, $foo is of the type Foo, and $bar is of the type Bar. But say if we were to add return types like this: function FooBar qux(); The type of qux isn’t a FooBar, it’s a function (more accurately, an argument-less, return-anything function). FooBar isn’t what qux is, it’s not qux’s type, merely what it returns. In a sense, I’d say there’s already a type here: function. Compare it to this: function qux(): FooBar; FooBar is what qux returns, function is what qux is. If we were to hypothetically add typed properties with the same syntax Hack has, they’d look like this: public Foo $foo; This would be consistent with parameters. And I think it goes along well with return types at the end: public Foo $foo; public function foobar(): FooBar; Here, it’s clear the second item is a function, and the previous item is a property of type Foo. …but hey, I could be wrong. Does this make sense to anyone? -- Andrea Faulds http://ajf.me/