Re: [RFC] Skipping parameters take 2

Am 19.01.2015 um 19:48 schrieb Adam Harvey:

On 17 January 2015 at 18:04, Andrea Faulds <ajf@ajf.me> wrote:

For consistency with list(), we could also just put nothing:

     foo($bar, , $baz);

Which is like:

     list($bar, , $baz) = $arr;

Thoughts?

That was Stas's original, original proposal way back when. I argued then for having "default" as a placeholder, and still would today — in the case where a function with, say, ten optional parameters[0] is being called and eight of them should be the default, I think it's a bit rough for somebody inheriting that code to have to count commas. Having a token increases readability, IMO, and costs us nothing except a few keystrokes, which isn't going to break the camel's back in a language that requires "function" each time you declare a function. Adam [0] Yes, that's probably poor API design. You and I both know someone will do it, though. :)

Pros & Cons _Simply skipping the argument out:_ pro:

    - same syntax as skipping entries used by list

con:

    - hard to read and to differ from mistakes
    - not an option for inheritance

_Using the keyword default:_ pro:

    - better to read and to differ from mistakes
    - usable on inheritance

con:

    - different syntax as list
    - not possible as alternative syntax for list as it has no "default" naming

_Using a special character:_ pro:

    - better to read and to differ from mistakes
    - usable on inheritance
    - possibly an alternative syntax for list (for consistency)

con:

    - different syntax as list
    - Not a good character found for it, yet

_Named Parameters:_ pro:

    - readability  (If caller is not required to call as assoc array)
    - not an option for inheritance

con:

    - paramter skipping is a side product with possible edge cases
    - Adds variable names to be part of the API
    - implementation complexity

In my opinion plain skipping parameters is a nice addition to PHP even if named arguments will be introduced. A special character would indeed the best option but as long as there is no good character it's not an option. @Stas: Any news on using default on inheritance ? Marc