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Date: Mon, 7 Sep 2015 19:28:37 +0100
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Subject: Re: [PHP-DEV] [RFC] [Discussion] Short Closures
From: ajf@ajf.me (Andrea Faulds)

Hi Levi,

Levi Morrison wrote:
> If this RFC passes I'd like to see one that builds on it to remove the
> { return <expr> ;} boilerplate of the above definition:
>
>      function reduce ($initial) ~> $fn ~> $input {
>          $accumulator = $initial;
>          foreach ($input as $value) {
>              $accumulator = $fn($accumulator, $value);
>          }
>          return $accumulator;
>      }
>
> I'm not saying it would be that syntax exactly but something like that
> would be nice if this RFC passes.

That looks rather weird to me, but I like the concept.

I think a possible improvement might be a generalised syntax, similar to 
that used for constants, that lets you use any \Closure object to define 
a function or method. Thus:

     function reduce = $initial ~> $fn ~> $input ~> {
         // ...
     };

This has that advantage that it isn't just useful for when you want to 
use the short syntax. You can also use it when you're obtaining a 
Closure in some novel way, perhaps a higher-order function:

     // where "add" is a function that adds two numbers
     function sum = reduce(0)("add");

With this, you don't have to write a wrapper function, or use a global 
variable, to define a proper top-level function.

Hope this is helpful.

-- 
Andrea Faulds
http://ajf.me/