> On 17 Mar 2023, at 05:33, Larry Garfield <la...@garfieldtech.com> wrote:
>
> On Thu, Mar 16, 2023, at 4:14 AM, Rowan Tommins wrote:
>>> On 15/03/2023 21:12, Dan Ackroyd wrote:
>>> Would it be desirable to split those two things into two separate
>>> RFCs, by having the first RFC not have native syntax support, but
>>> instead another static method on Closure? e.g. something like:
>>>
>>> Closure::partial($callable, array $position_params, array
>>> $named_params): Closure {}
>>
>>
>> Hm... now we have the first-class callable syntax, making it an instance
>> method on Closure would allow this:
>>
>> $mapFoo = array_map(...)->partial([$foo]);
>> $filterFoo = array_filter(...)->partial([1 => $foo]);
>>
>> Which could copy over the full signature, so be equivalent to this:
>>
>> $mapFoo = static fn(array ...$arrays): array => array_map($foo, ...$arrays);
>> $filterFoo = static fn(array $array, int $mode = 0): array =>
>> array_filter($array, $foo, $mode);
>>
>> While being a similar length to a much less rich version:
>>
>> $mapFoo = fn($array) => array_map($foo, $array);
>> $filterFoo = fn($array) => array_filter($array, $foo);
>
> Fascinating! I... don't know if we considered something like that or not 3
> years ago. It's been a while.
>
> It's definitely not as nice as the integrated syntax, but it does have the
> advantage of the implementation almost certainly being rather pedestrian in
> comparison. That approach would favor left-to-right application, but not
> force it, which is probably sufficient.
>
> As a thought experiment, if we had that syntax and functions that were
> designed to be used with them, it would look like so:
>
> function amap(callable $c, iterable $it) { ... }
> function implode(string $sep, iterable $it) { ... }
> function length(string $s) { ... }
>
> $arr = [1, 2, 3];
>
> $a2 = amap(...)->partial(chr(...))($arr);
>
> $str = implode(...)->partial(',')($a2);
>
> Or, if combined with pipes:
>
> $size = $arr
> |> amap(...)->partial(chr(...))
> |> implode(...)->partial(',')
> |> length(...);
>
> Which... is not terrible, especially as it doesn't preclude using higher
> order functions for more control.
>
> We would likely want partial() to accept positional args (left to right) and
> named args. And I'm more than happy to say now that the capture is only by
> value, ever.
>
> I wonder if there's a shorter name we could use than "partial" to make it
> more readable? Or perhaps an operator that applied only to closure objects?
>
> --Larry Garfield
>
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>
It’s not shorter than “partial” but given “bindTo()” exists, “bindArgs()” is at
least clear about what it’s doing.
Cheers
Stephen
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