Hi, > On 7 Feb 2015, at 22:03, Pavel Kouřil <pajou...@gmail.com> wrote: > > On Sat, Feb 7, 2015 at 9:57 PM, Andrea Faulds <a...@ajf.me> wrote: >> Hi, >> >>> On 7 Feb 2015, at 20:47, Andrea Faulds <a...@ajf.me> wrote: >>> >>>> On 7 Feb 2015, at 10:57, Pavel Kouřil <pajou...@gmail.com> wrote: >>>> >>>> I just realized it now (I brought it up in a different manner when >>>> there was discussion about the RFC), but I didn't notice there was a >>>> totally false statement about it in the RFC itself. You probably >>>> should fix it. I'm speaking about the "Strict type checking, which is >>>> used by many popular programming languages, particularly ones which >>>> are statically-typed, such as Java, C#, Haskell, or Facebook's Hack. >>>> It is also used for non-scalar parameter type hints in PHP. With this >>>> approach, an argument is only accepted if its type is exactly the same >>>> as the parameter." paragraph. >>>> >>>> This is NOT true (at least for C# and Java), as you can read here in >>>> the documentations of respecitve languages so you should not compare >>>> the strict version of the typing implemented in PHP with other >>>> strongly typed languages, because the PHP's "strict" is stricter than >>>> strongly static typed languages. I really hope noone voted with the >>>> thought that the strict typing acts as it does in Java and C#. >>>> >>>> https://msdn.microsoft.com/en-us/library/y5b434w4.aspx >>>> http://docs.oracle.com/javase/specs/jls/se7/html/jls-5.html#jls-5.1.2 >>> >>> I don’t think it’s unfair. There’s a limited set of permitted conversions >>> in some strictly-typed languages, but it’s still strictly-typed. >> >> To add to the previous email: >> >> * Most of these conversions are between different sizes of the same type >> (float/double, char/short/int/long, etc.), but this is irrelevant to PHP >> which has only one size for each type >> * The other ones are between types (int to float) >> * Always allowing implicit conversions from float to int is very likely to >> cause data loss, so it’s not unreasonable for PHP to prevent this specific >> case >> * Always allowing implicit conversions from int to float is sometimes going >> to cause data loss, so it may also be reasonable for PHP to prevent this >> specific case >> * Requiring an exact type match has the least mental overhead, and allows >> types to be checked at compile-time >> > > Yeah, but you say in the RFC that "With this approach, an argument is > only accepted if its type is exactly the same as the parameter." when > speaking about C# and Java - which is NOT true.
C# and Java aren’t really considered weakly-typed. Technically they’re not “fully strict” I guess, but if you were to give example of strictly-typed languages, you’d probably include C# and Java in that list - so I did. > You should have > written that the way of strict typing in PHP is even more strict than > Java's and C# one - because the way it's written now is unfortunately > misinforming the readers of the RFC. It might be somewhat misleading. Really, what’s “weak” and what’s “strict” is rather subjective: C is sometimes considered weak, sometimes strict. I’d say it’s more “weak” because all sorts of definitely wrong conversions are allowed implicitly and merely generate warnings. C# and Java are more careful here, so I’d say they’re “strict” even though I suppose they do have a degree of weak typing. > Also, there's no need to mention > float -> int, because that one is definitely wrong. But for the int > (and long, etc) -> float (and double) - how do the languages you > mentioned in the RFC handle that conversion? From Microsoft’s documentation that you linked, it sounds like they just always convert and never error, so you’d get data loss in some cases (just like you do in PHP with an explicit cast). > I'm wishing more and more that the RFC doesn't pass (even though I'd > LOVE to have typehints in PHP as a userland developer) and someone > else will make a better version of typehints RFC for PHP 7, because > this one feels really like you took an ok-ish RFC (one that would be > good for PHP) and slapped a strict typing on it without enough > research about strong typing in other languages. I am familiar with other languages, I just disagree with their approach. > And as I said myself > multiple times in the past, the declare syntax IS just ugly (and > changing how code works by writing one line is an ugly principle as > well, IMHO). :( I prefer this approach to the inconsistency the other approaches suggested thus far lead to. -- Andrea Faulds http://ajf.me/ -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
