Overloaded Function

PHP actually does not support function overloading, as functions distinguished but name only. This is a class that helps to imulate function overloading in PHP.

General usage

General usage

Function cases provided as an array of callables, where key is a signature of parameters types.

1. Simple signature:

Parameters signature is a list of types separeted by comma.

    $func = new OverloadedFunction([
        'integer, integer' => function ($a, $b) { return $a + $b; },
        'string, string' => function ($a, $b) { return $a . $b; }
    ]);

    var_dump($func(1, 1)) // => 2
    var_dump($func('1', '1')) // => '11'

2. Union types:

Sometimes your parameter need to be of a kind, that implements not one interface, but several.

    $func = new OverloadedFunction([
        'ArrayAccess&Countable' => function ($i) { return true; }
    ]);

    var_dump($func(new ArrayIterator)) // => bool(true)

3. Intersection types:

Sometimes you allow parameter to be not of one type, but of several types.

    $func = new OverloadedFunction([
        'string|integer' => function ($i) { return true; }
    ]);

    var_dump($func(1)) // => bool(true)
    var_dump($func('1')) // => bool(true)

4. Typed arrays:

You can restrict your parameter to be an array of elements of certain types.

    $func = new OverloadedFunction([
        'integer[]' => function ($arr) { return 'integer'; },
        'integer|string[]' => function ($arr) { return 'mixed'; }
    ]);

    var_dump($func([1, 2, 3])) // => string(7) "integer"
    var_dump($func([1, 2, '3'])) // => string(5) "mixed"

5. Optional parameters:

Sometimes you allow parameter to be optional. Make sure you provide default values for such cases.

    $func = new OverloadedFunction([
        '?integer' => function ($i = 1) { return $i; }
    ]);

    var_dump($func(1)) // => bool(true)
    var_dump($func()) // => bool(true)

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