Am 19.01.2015 um 19:48 schrieb Adam Harvey:
On 17 January 2015 at 18:04, Andrea Faulds <
[email protected]> 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