On May 26, 2010, at 5:20 PM, Zeev Suraski wrote:
> At 23:44 26/05/2010, Davey Shafik wrote:
>
>> On May 26, 2010, at 3:08 PM, Zeev Suraski wrote:
>>
>> > At 21:12 26/05/2010, Pierre Joye wrote:
>> >> As PHP's type system is seen as a big plus,
>> >> I have to say that many users consider it as a plus in the
>> >> implementation of a given method function or method. But the same
>> >> users ask to have something more strict for the methods signature. I
>> >> think it is a valid request and somehow makes sense too.
>> >
>> > I think that the proposed auto-converting type hints answer this request
>> > quite well...
>> >
>> > Zeev
>>
>> Do you propose to have a warning when the types are a mis-match, similar to
>> the
>> array->scalar conversion example from Gustavo? (strtoupper(array('ABC')))
>>
>> If you have a warning or notice, that warns of potential loss of data
>> accuracy, then
>> I think I'd be OK with auto-converting.
>
> Yep - that's exactly the idea.
>
>> Having said that, all other type hints are strict, throwing a catchable
>> fatal error — consistency
>> for what is essentially the same syntax, is more important IMO.
>
> In my opinion it's really a matter of whether the value makes sense in its
> context or not. Much like a function that requires an object of type X will
> accept an object of type Y if Y extends from X - because Y is a kind of X,
> "42" is a kind of an int. It's true that no conversion is made in the former
> case, but still - across 99.9% of PHP, "42", 42 and 42.0 are the same thing.
>
>> Would it be possible to support two syntaxes:
>>
>> function foo( (int) $bar) { } // auto-cast to int
>> function foo(int $bar) { } // require int
>
> I would advise against it - IMHO having both strict and auto-converting type
> hints means having all of the issues of strict typing, and making that worse
> by having similar confusing syntaxes on top of it... In general I think
> there should be an exceptionally good reason to add core language syntax.
> Auto-converting type hints would cater for the vast majority of real world
> use cases. While I'm sure we can come up with situations where you'd want a
> strict type check, for those few cases - you could simply use is_int() - no
> need to add a language-level support for it.
>
> Zeev
You could just as easily say to do:
function foo($bar) {
$bar = (int) $bar;
}
as:
function foo($bar) {
if (!is_int($bar)) {
// error
}
}
Why bother with either if that's the case? Why not add support for something
like:
function foo($bar) {
(int) &$bar;
}
to allow for in-place casting (instead of temp-var+assign) and make it a
shortcut.
I'm sorry, but your reasoning is silly IMO. Type checking or casting are both
currently
easy enough to do; the only value in the auto-casting is to inform the user of
loss of
precision when they write against it. Does that really need language-level
support?
It could just as easily be part of the docblock.
- Davey
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