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Date: Thu, 04 Aug 2011 22:20:55 +0200
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Subject: Re: [PHP-DEV] Re: An implementation of a short syntax for closures
From: sebastian.krebs.berlin@googlemail.com (Sebastian Krebs)

Just two examples, why I think, this is a not a good idea. Simple typos 
can produce hard to track errors. Its just confusing

$x = 4;
$y = ($x);{
     return $x*2;
}


// and

$x = 4;
$x = ($x)
{
     $y = $x*2;
}



On 04.08.2011 21:52, Jezz Goodwin wrote:
> Hello PHP Internals,
>
> This is my first message to the list. I've been reading via the archive
> since I read the 5.4RC1 announcement. (Keep up the great work guys - I'm
> loving the new stuff)
>
> Up until now I haven't had anything to say that wasn't already being
> talked about, but the topic of short hand syntax is of particular
> interest to me.
>
> Before I start, I think I need to make clear that I am in general not a
> fan of making cryptic code (ala perl). I tend to use long descriptive
> variable names and try to make my code easy to read so that comments
> aren't usually necessary.
>
> Saying that though, I am a big supporter of the new short hand array
> syntax. From a grammatical point of view, I see no reason why my code
> needs to be scattered with the word 'array'. The simple square brackets
> ['a'=>'b'] I find just as easy to understand and they don't confuse me.
> (unlike something along the lines of regex, that can easily confuse).
>
> I see the desire to wanting to remove the word function as a similar
> issue. When you use inline functions a lot, your code is filled with
> lots of the word 'function'. This word doesn't necessarily need to be
> there for your code still to make sense.
>
> Also, on a similar vein of thought, if your function is only doing
> something small, why do we need to put the word 'return' in there?
>
> I have been thinking of what syntax(s) could work to shorten the code
> but not to make the code confusing. I am splitting up my ideas in to
> separate sections. I think that if a short-hand function syntax is to be
> accepted, it should be useful in many circumstances - eg, it shouldn't
> necessarily be limited to one liners.
>
>
>
> Okay, here is a base example:
>
> $modify = function( $x )use( $my_constant ){ return $x + $my_constant; };
>
>
> 1) REMOVING THE WORD 'function':
>
> One solution is to simply remove the word function completely:
>
> $modify = ( $x )use($my_constant ){ return $x + $my_constant; };
>
> On first glance, to me, this doesn't look like I'm starting to write a
> function. I could perhaps be opening a bracket to do some maths. So,
> what could be done to make it more obvious? I suggest using a character
> to represent function. Personally I like colon:
>
> $modify = :( $x )use( $my_constant ){ return $x + $my_constant; };
>
> Now, I know this doesn't immediately scream function, but it is a
> different/specific syntax which should hopefully lead to less confusion.
>
>
>
> 2) REMOVING THE WORD 'return':
>
> Okay, my function is still a bit wordy for what it's doing. How do we
> remove return? I quite like the use of => that has been suggested in
> previous posts.
>
> $modify = :( $x )use( $my_constant )=> $x + $my_constant;
>
>
>
> 3) REMOVING THE WORD 'use':
>
> Personally I don't think use is causing a problem, I find it helps the
> grammar of this function. If it was to go though, it could be replaced
> with something like a colon:
>
> $modify = :( $x : $my_constant )=> $x + $my_constant;
>
> Is this going too far? Is it now too cryptic?
>
>
>
> 4) REMOVING THE BRACKETS?
>
> In lots of the examples of short hand closures in other languages there
> are no brackets. I think that might be going too far, but perhaps not:
>
> $modify = : $x : $my_constant => $x + $my_constant;
>
> Too much! This line simply confuses me!
>
>
>
> OTHER EXAMPLES
>
> So, personally I don't think shortening needs to go as far as 3 or 4.
> But, I am a fan of 1 and 2.
>
> To demonstrate more how this might look, I'm using the code examples
> Lazare used in his original post:
>
> // Mapping:
> $a->select( function($x){ return $x->getName(); } );
>
> // Filtering:
> $a->where( function($x)use($y){ return $x==$y; } );
>
> // Currying:
> $add = function($x){ return function($y)use($x){ return $x+$y; }; };
>
>
>
> With my examples of shortening, these become:
>
> // Mapping:
> $a->select( :($x)=> $x->getName() );
>
> // Filtering:
> $a->where( :($x)use($y)=> $x==$y );
>
> // Currying:
> $add = :($x)=> :($y)use($x)=>$x+$y ;
>
>
> Hmm... I don't like my currying example, it's starting to boggle my
> mind. How about:
>
> $add = :($x)=>( :($y)use($x)=>$x+$y );
>
> Much better.
>
>
>
> Regardless of all of this, I actually don't find myself using too many
> inline functions. (Not to the extent I was writing 'array' all over my
> code anyway) - So I can't argue srongly about function shortening making
> it's way in to PHP.
>
> Perhaps once we're all using inline functions on every other line of our
> code there'll be a bigger demand for it!
>
>
> Best regards,
> Jezz Goodwin
>
>
>
>
>