Re: Return Type Hinting for Methods RFC

On 12/22/2011 11:49 AM, John Crenshaw wrote: > From: Rasmus Lerdorf [mailto:rasmus@lerdorf.com] > >> How is that hard? >> >> function age_lookup($age) { >> return $coll->find(array('age' => (int)$age); >> } >> >> but again here, doing a strong type check on the parameter isn't making your life >> easier. It simply pushes the responsibility to the caller and introduces a tricky unrecoverable >> error that will drive you crazy unless you have 100% regression test coverage (which is kind of >> impossible since the number of inputs is infinite) or great static analysis tools. > PHP is not a compiled language, so you end up not catching these until runtime which is > obviously sub-optimal. > >> -Rasmus > > This will silently fail in a very bad way when the caller accidentally passes in (for example) > an array. With a scalar type hint it would die loudly (quickly alerting the developer to the > problem) and code analysis tools (even just a decent IDE) could highlight the error even before it > is executed. That's an argument for "scalar" as the type hint, not for "int" vs. "string". I'm not against "scalar" as a type hint. I am against hints that prevent interchangeable types from being passed. scalar, array, object, callable are fine. -Rasmus