λ Functional
Siler is bundled with the Siler\Functional namespace. It brings some function declarations that aids the work with another first-class and high-order PHP functions!
Returns a Closure that returns its given arguments.
use Siler\Functional as λ;array_map(λ\identity(), [1, 2, 3]);// [1, 2, 3]
Doesn't seem useful at first, but working with the functional paradigm, you'll find the reason shortly.
Almost like identity(), but it always returns the given value.
use Siler\Functional as λ;array_map(λ\always('foo'), range(1, 3));// [foo, foo, foo]
A functional if/then/else.
use Siler\Functional as λ;$pred = λ\if_else(λ\equal('foo'))(λ\always('is foo'))(λ\always('isnt foo'));echo $pred('foo'); // is fooecho $pred('bar'); // isnt foo
Partial application refers to the process of fixing a number of arguments to a function, producing another function of smaller arity. Given a function
Nothing like a good example:
use Siler\Functional as λ;$add = function ($a, $b) {return $a + $b;};$add2 = λ\partial($add, 2);echo $add2(3); // 5
Works with any callable:
use Siler\Functional as λ;$explodeCommas = λ\partial('explode', ',');print_r($explodeCommas('foo,bar,baz'));/*** Array* (* [0] => foo* [1] => bar* [2] => baz* )*/
A pattern-match attempt. Truthy Closure evaluations on the left calls and short-circuits evaluations on the right.
use Siler\Functional as λ;$nameOf = λ\match([[λ\equal(1), λ\always('one')],[λ\equal(2), λ\always('two')],[λ\equal(3), λ\always('three')],]);echo $nameOf(1); // oneecho $nameOf(2); // twoecho $nameOf(3); // three
There are a lot more of them. A good place it check it out are the tests.
