Edit report at https://bugs.php.net/bug.php?id=66368&edit=1
ID: 66368
Comment by: master dot training365 at gmail dot com
Reported by: chriswarbo at gmail dot com
Summary: Operators should also be functions
Status: Assigned
Type: Feature/Change Request
Package: *General Issues
Operating System: Irrelevant
PHP Version: Irrelevant
Assigned To: ajf
Block user comment: N
Private report: N
New Comment:
https://pastelink.net/sd8e3bqt
Previous Comments:
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[2022-02-13 01:57:21] master dot training365 at gmail dot com
http://git.province.namur.be/Wikiew/Techi/wiki/Creat5
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[2017-09-12 13:52:28] cmb@php.net
FTR: a respective "Operator functions" RFC is currently under
discussion: <https://wiki.php.net/rfc/operator_functions>.
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[2014-01-02 12:23:24] chriswarbo at gmail dot com
It is sufficient to do:
$o = function($l, $r) {
return $l + $r;
};
But after defining such a function for the umpteenth time, I decided to raise this issue. I
don't think I'm alone in using such definitions, since it's a common-enough pattern
that we had array_sum built in to the language even before we had lambdas and array_reduce
(array_sum is just array_reduce curried with $o and 0).
One solution would be to build in functions like $o to prevent the need to define them over and over
in-line or in libraries, but I'd rather not be 'that guy' who wants his own
helper-functions built-in, since adding new functions bloats the language and, more importantly,
burdens developers with extra complexity ("Should I use + or $o?").
Instead, I think it's an opportunity to fix the treatment of operators, especially since
functions like $o are just eta-expansions of operators, and eta-expansion is always a useless
transformation:
function eta($f) {
return function ($x) {
return $f($x);
};
}
call_user_func(eta($x), $y) === call_user_func($x, $y)
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[2014-01-01 14:43:23] krakjoe@php.net
Ok, I understand a bit clearer what you're asking for ... but don't really see why; I
cannot imagine a time where:
$o = '+';
$o(10, 20);
Is required such that:
$o = function($l, $r) {
return $l + $r;
};
Does not suffice.
Maybe someone else will get it, I don't ...
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[2014-01-01 13:04:19] chriswarbo at gmail dot com
As for "[]" and "->" being functions (or function-like), consider the
following:
function subscript($array, $index) {
return $array[$index];
}
array_map('subscript', $my_arrays, range(0, 9));
function prop($object, $property) {
return $object->$property;
}
array_map('prop', $my_objects, $props);
Personally I don't use the above functions, but I make heavy use of a function
"lookup" which does both (based on the argument's type) plus a few bells and whistles
(recursively looking up an array of identifiers, exception and error handling for magic methods,
etc.).
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