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Subject: Re: [PHP-DEV] Suggestion Method Constant
From: markyr@gmail.com (Mark Randall)

On 12/10/2017 22:32, Sara Golemon wrote:
> answer, but (Foo::class.'::bar') may be what some would expect.
> Ideally we'd have first-class references to functions.
> 
> -Sara
> 

To chime in..

To my mind, references to functions is the holy grail so far as 
beginning to clean up the entire ecosystem around function calls.

IMHO directly referencing MyClass::StaticFunction eventually needs to 
return a "Function" class that is directly invokable.

I see 3 contexts that the parser would need to handle:


1. Standard Calling

MyClass::StaticFunction(1, 2, 3);
my_function(1, 2, 3)
$inst->my_function(1234);

Obviously returning a full function object to useland for every call 
would be considered wasteful, so the parser would need to call these as 
before.



2. Returning a native "Function" class, an __invokeable hybrid of 
Callable and Reflection;

$method = MyClass::StaticFunction;
$method(1, 2, 3);

$method = $inst->my_function; /* bind to $inst */
$method(1, 2, 3);

$method->getName();
$method->getArgumentCount();
$method->getBinding();




3. Returning closures when the argument list includes one or more 
late-bound values, so we can finally put the pipe operator to bed at the 
same time as getting a bunch of other power from it.

$method = MyClass::StaticFunction($1, 'Arg 1', 'Arg 3);
$method('Arg 1');

$method = $inst->my_function('Arg 1', 'Arg 2', $1);
$method('Arg 3');

chain(
   'Random String',
   func_1($1, 'Hello', 'World'),
   func_2($1, 'Peace', 'Out'),
   func_3('ThisOneNeeds', 'Arg3ReplacingInstead', $1),
   func_3($1, $1, 'HowAboutOneWhichUsesTheSameArgumentTwice')
);

function chain($start, ... $fns) {
    foreach ($fns as $fncall) {
      $start = $fncall($start);
    }

    return $start;
}


--
Mark Randall