I wrote a small patch that enables this kind of syntax in PHP:

foo()();

What it means is that if foo() returns callable value (which probably
should be function name or closure) then it would be called.
Parameters
and more than two sets of () work too.
Of course, this is mostly useful for doing closures, and that was
primary drive for implementing it - to make working with closures and
especially function returning closures easier.
What does not work currently is $foo->bar()() - since it is
surprisingly
hard to tell parser it's not {$foo->bar}()() - which of course is not
what I want to do.

The patch is here: http://random-bits-of.info/funcfunc.diff

What do you think? If somebody has better idea btw - maybe make
something like {foo()}() - and make that work for any expression
inside
{} - that might work too. So, what do you think?

If I understand what this does...

I think it would be far easier to just keep using:
$foo_closure = foo();
$foo();

then to try to deal with foo()();

foo()(); just seems a bit too arcane to me...

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I just want you to buy an Indie CD for yourself:
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Hi!

I wrote a small patch that enables this kind of syntax in PHP:

foo()();

What it means is that if foo() returns callable value (which probably should be function name or closure) then it would be called. Parameters and more than two sets of () work too.
Of course, this is mostly useful for doing closures, and that was primary drive for implementing it - to make working with closures and especially function returning closures easier.
What does not work currently is $foo->bar()() - since it is surprisingly hard to tell parser it's not {$foo->bar}()() - which of course is not what I want to do.

I like it!

regarding $foo->bar()()…
is it possible to use precedence rules here? something like:

($foo->bar())();

What do you think? If somebody has better idea btw - maybe make something like {foo()}() - and make that work for any expression inside {} - that might work too. So, what do you think?

why curly braces?
Parentheses would feel more natural here.

Would be nice if something like this worked too:

(new Class())->method();

hi Stan,

Hi!

I wrote a small patch that enables this kind of syntax in PHP:

foo()();

What it means is that if foo() returns callable value (which probably should
be function name or closure) then it would be called. Parameters and more
than two sets of () work too.
Of course, this is mostly useful for doing closures, and that was primary
drive for implementing it - to make working with closures and especially
function returning closures easier.
What does not work currently is $foo->bar()() - since it is surprisingly
hard to tell parser it's not {$foo->bar}()() - which of course is not what I
want to do.

The patch is here: http://random-bits-of.info/funcfunc.diff

What do you think? If somebody has better idea btw - maybe make something
like {foo()}() - and make that work for any expression inside {} - that
might work too. So, what do you think?

I'm not a fan of this kind of syntaxic sugars, especially for
procedural implementation only. What are the benefits?

Cheers,

Pierre

@pierrejoye | http://blog.thepimp.net | http://www.libgd.org

Hi!

I wrote a small patch that enables this kind of syntax in PHP:

foo()();

I'd rather see two other things that are missing, support for
dynamic object and array de-referencing like
(new class)->method() and get_array()["index"].

I honestly don't see func()()()() make anything better in the
world of a PHP programmer.

Regards,
Mike

Hello,

I wrote a small patch that enables this kind of syntax in PHP:

foo()();
...

I think language enhancements with no BC breaks that offer a wider
toolset to programmers is a good thing. I would also like to see the
other ideas in this thread implemented such as array access & object
creation.

The only thing I do not like about this is I do not beleive it fits
the PHP error model. Lets just say Bar::foo($arg) returns a function
callback or FALSE/NULL on a error condition. So you end up with a
function call to something that is not callable, the PHP way under
this case is to have a fatal error. I would rather not see more ways
to cause fatal errors in PHP (call to undefined method has gotten a
bit more popular since object chaining has risen in popularity as
well). Of course I know exceptions are likely out of the question for
these kinds of cases as well. These thoughts do not apply to array
access or object creation.

Regards,

-Chris

-----Original Message-----
From: Stanislav Malyshev [mailto:stas@zend.com]
Sent: 19 January 2010 00:28
To: 'PHP Internals'
Subject: [PHP-DEV] function call chaining

Hi!

I wrote a small patch that enables this kind of syntax in PHP:

foo()();

What it means is that if foo() returns callable value (which
probably should be function name or closure) then it would be
called. Parameters and more than two sets of () work too.
Of course, this is mostly useful for doing closures, and that
was primary drive for implementing it - to make working with
closures and especially function returning closures easier.
What does not work currently is $foo->bar()() - since it is
surprisingly hard to tell parser it's not {$foo->bar}()() -
which of course is not what I want to do.

The patch is here: http://random-bits-of.info/funcfunc.diff

What do you think? If somebody has better idea btw - maybe
make something like {foo()}() - and make that work for any
expression inside {} - that might work too. So, what do you think?

Stanislav Malyshev, Zend Software Architect
stas@zend.com http://www.zend.com/
(408)253-8829 MSN: stas@zend.com

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unsubscribe, visit: http://www.php.net/unsub.php

I've run into problems with

$foo1;

If the closure attempts to change the value of $foo[1] then PHP
complains.
So was forced to assign to a temporary variable before hand.

$f = $foo[1];
$f();

I guessing foo()() could also suffer from the problem?

Jared

Stanislav Malyshev wrote:

Hi!

I wrote a small patch that enables this kind of syntax in PHP:

foo()();

What it means is that if foo() returns callable value (which probably
should be function name or closure) then it would be called. Parameters
and more than two sets of () work too.
Of course, this is mostly useful for doing closures, and that was
primary drive for implementing it - to make working with closures and
especially function returning closures easier.
What does not work currently is $foo->bar()() - since it is surprisingly
hard to tell parser it's not {$foo->bar}()() - which of course is not
what I want to do.

The patch is here: http://random-bits-of.info/funcfunc.diff

What do you think? If somebody has better idea btw - maybe make
something like {foo()}() - and make that work for any expression inside
{} - that might work too. So, what do you think?

I don't mind the foo()() syntax, especially now that we have closures.
But people are right, we have a longstanding feature request for
$foo()[0] as well, so if we start down this path of adding chaining, we
should do that one as well and see if any others make sense.

I do think the syntax is a bit ugly, but I also think it is clear what
it does and doesn't obscure/mislead the semantics of the call the way
the (new foo)->bar() suggestion does.

Not sure the {} expression syntax is needed. What sort of expressions
do you see being useful here that would need the braces? Stuff like
$a$idx works today without needing any extra syntax. Are you
thinking along the lines of:

{strtolower($a[$idx])}()

or something like that? That would make the "I hate linefeeds and
semi-colons" crowd happy, I guess.

-Rasmus

Op 1/19/10 1:27 AM, Stanislav Malyshev schreef:

Hi!

I wrote a small patch that enables this kind of syntax in PHP:

foo()();

What it means is that if foo() returns callable value (which probably
should be function name or closure) then it would be called. Parameters
and more than two sets of () work too.
Of course, this is mostly useful for doing closures, and that was
primary drive for implementing it - to make working with closures and
especially function returning closures easier.
What does not work currently is $foo->bar()() - since it is surprisingly
hard to tell parser it's not {$foo->bar}()() - which of course is not
what I want to do.

The patch is here: http://random-bits-of.info/funcfunc.diff

What do you think? If somebody has better idea btw - maybe make
something like {foo()}() - and make that work for any expression inside
{} - that might work too. So, what do you think?

cool as ice! :-)

I do worry how many painful edge cases this throw up and
additionally how many beginner coders with a bit of JS experience would continuely
complain/moan/question why PHP didn't work they [think] JS works, for instance the
classic JS closure-type tricks, e.g.:

doIt = function(a, b) { return function() { return b(a);} }
func = (function() { var bar = ''; return function(foo) { doIt(foo, bar)(); } })();
document.write(func(function(a) { return a + '-fooey'; }));

it's quite obvious how easy it is to make javascript code very difficult to follow,
personally I love it, but using it sensibly requires alot of care and attention,
it's worth considering whether giving PHPer another very powerful gun is wise
choice ... especially given how often they/we/(me!) put holes in feet.

I can imagine you'd be opening yourself up for sleepless night and lots of
unwarranted abuse for having offered a new bit of greatness.

given that Closures are still in their relative infancy (mostly in the context of
production use) and the fact that this is liable to still of itself be in flux,
and additionally the mountain of work/details (AFAIKT) required for PHP6, that, maybe,
such functionality should be put on the backburner for now. at some stage all the new stuff
(most notably Closures) will stabalize to such a degree that it would become more
manageable to introduce such a thing.

just my 2 cents.