Re: What do we need strict scalar type hints for?

Hi Andrea, Andrea Faulds wrote: > Hi Christoph, > >> On 2 Feb 2015, at 22:38, Christoph Becker <cmbecker69@gmx.de> wrote: >> >> And frankly, I don't see what's wrong with a weak type hint in this case: >> >> function addVat(float $amount) {...} >> >> You're returning a float, anyway. > > Given you’re dealing with currency, and given the fairly serious issues with precision loss > with int->float conversions and vice-versa… I would be highly concerned if you used a weak type > hint there. Well, considering the given function body ($amount * 1.19), that doesn't seem to be an issue. In the general case, if one has to deal with currency, float is problematic anyway. I'd rather use a rational type in this case (i.e. an immutable class with GMP[1] numerator and denominator properties and the respective methods), which could be combined with the actual currency (i.e. a "Money" class), if necessary. >> OTOH, strict type hints would require a lot of manual conversions. > > Sure, they do. But they’re *explicit* manual conversions, ones you can easily grep for and > that are obvious when reading code. Indeed, code is read far more often than it's written (hopefully :)), but still it might be annoying for many PHP programmers to write these explicit manual conversions in the first place.[2] [1] Or int, if your Big Integer Support RFC will pass (which I would welcome, BTW). [2] I'm aware that your current Scalar Type Hints RFC would not require these manual conversions, but that doesn't seem to be the topic of *this* thread. :) -- Christoph M. Becker