Re: Pipe Operator v2
| From: | Levi Morrison | Date: | Fri, 20 Jan 2017 15:24:24 +0000 |
| Subject: | Re: Pipe Operator v2 | ||
| References: | 1 2 3 4 5 | Groups: | php.internals |
| Request: | Send a blank email to internals+get-97892@lists.php.net to get a copy of this message | ||
On Fri, Jan 20, 2017 at 3:53 AM, François Laupretre <flaupretre@free.fr> wrote:
> Le 19/01/2017 à 22:53, Levi Morrison a écrit :
>>
>> On Thu, Jan 19, 2017 at 11:12 AM, François Laupretre <flaupretre@free.fr>
>> wrote:
>>>
>>> Le 19/01/2017 à 13:54, Levi Morrison a écrit :
>>>>
>>>> The
|> symbol would be the piping operator with
>>>> these semantics:
>>>> 1. Evaluate the left-hand side.
>>>> 2. Evaluate the right-hand side. Assert that the result is
>>>> callable.
>>>> 3. Pass the result from 1. as the single argument to 2.
>>>
>>>
>>> May I suggest extending your 3rd rule to : when the right hand side has
>>> the
>>> form of a function call, insert the result from 1. as first argument of
>>> 2.
>>> This way, right hand side may specify additional arguments
>>
>> If we only had |> this may be good but since we are also
>> proposing
>> $$ then this renders your suggestion unnecessary:
>>
>> $string |> trim($$)
>>
>> Would work just fine with no performance overhead.
>>
>> Additionally, you could write:
>>
>> $input |> array_map($fn, $$)
>>
>> Or:
>>
>> $input |> array_filter($$, $fn)
>>
>> Basically, $$ gives the flexibility of passing additional
>> arguments
>> and keeps |> simple. No need for additional rules for
>> |>.
>
>
> Right, I just suggest to make the '$$' optional when used as first arg of a
> rhs call. Except complex cases like array_xx() functions which will
> generally require an explicit '$$', most cases will feature a '$$' as first
> arg of a function call. This may be considered as better because more
> explicit, but I think the case is prominent enough to justify this
> 'shortcut'.
>
> Another question: Will you accept several occurences of '$$' in a RHS ?
>
> Last, a cosmetic suggestion : replace '$$' with '$<' (more explicit as
> 'input data', imo).
>
> Regards
>
> François