<p><pre><code> Fatal error: Argument 1 passed to myLog() must be of the type string, integer given, called in /home/vagrant/basic/main.php on line 9 and defined in /home/vagrant/basic/main.php on line 4
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"HHVM says the error occurred on line 6 where PHP says it occurred on line 9. I prefer HHVM's approach here as it shows us where we called the function with the bad data, not where the function is defined that we are calling with bad data."<p>Hrm, PHP is telling you both line 4 and line 9, as where the function is defined and where it's being called with bad data, which is quite nice. In comparison, HHVM is saying line 6, which is a closing brace for the myLog function. In my books, PHP's approach is way way better then HHVM's
It's worth pulling out what I think is the most fundamental difference between the two type systems, from the end of the article:<p><i>After writing a couple small programs in Hack I've realized that it's not types themselves that make writing Hack enjoyable: it's the tight feedback loop Hack creates between the machine and myself. Integrating the Hack type checker into my editor means that my entire codebase is analyzed in a split second as soon as I save a file. This immediately surfaces any dumb, or subtle mistakes I made. I find myself writing code fearlessly: when I forget what a function returns, I just write code that calls it with what I think it returns. If I'm wrong, the type checker will tell me immediately. I can fix it quickly, and move on.</i><p>Hack's type system is static -- it's enforced by a static analysis tool that instantly reports errors in all of your code. PHP can only report errors that it actually encounters at runtime. Along with the "fearlessness" above, it also means that you might miss you forgot to check for a null in an error case... until it explodes at runtime in production. Hack's static type system can mechanically check for all of these immediately.
I really like writing hack and haven't tried PHP7. It makes a huge difference having types. If you have a function<p><pre><code> function dowork(@?string $w)
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You can allow execution to continue but still log the error. It's made me aware of all sorts of edge case bugs that I never would have been able to find before.<p>XHP has allowed me to do the same, by forcing me to write well formed html and I love it
> HHVM calls this a "catachable" fatal error. This is interesting as in the RFC the error shown actually matches HHVM's error.<p>It <i>was</i> a "catchable" fatal error (i.e. E_RECOVERABLE_ERROR) in PHP 5.x for typehints. But PHP 7 is changing it to be an Exception instead, and for some reason it currently produces an inaccurate error message in the master branch - it should say "Uncaught exception" (which it is), but that's not been fixed yet. Trunk builds aren't ready for production use, etc.
For nullable types, there's a plan/rfc to have them too<p><a href="https://github.com/php/php-src/pull/1045" rel="nofollow">https://github.com/php/php-src/pull/1045</a>
<a href="https://wiki.php.net/rfc/nullable_types" rel="nofollow">https://wiki.php.net/rfc/nullable_types</a><p>not for 7.0 but hopefully for 7.1