function _memoize($function, $hashFunction = NULL, &$cache = NULL)
{
return Underscore::memoize($function, $hashFunction, $cache);
}
/**
* @tags functions
*/
public function testMemoize()
{
// it should return a memoized version of the function
$fn = function () {
static $count = 0;
return ++$count;
};
$memo = _::memoize($fn);
for ($i = 0; $i < 3; $i++, $memo()) {
}
$this->integer($memo())->isEqualTo(1);
// it should be possible to override the hash function
$hash = function ($args) {
return array_sum($args);
};
$fn = function ($a, $b, $c) {
return $a + $b + $c;
};
$memo = _::memoize($fn, $hash);
$res[] = $memo(1, 2, 3);
$res[] = $memo(1, 4, 5);
// is different from $a because hash function uses all arguments
$res[] = $memo(1, 6, 7);
// is different from $a because hash function uses all arguments
$this->array($res)->isEqualTo([6, 10, 14]);
// it should be possible to override the cache
$cache = [];
$fn = function ($a) {
return $a * $a;
};
$memo = _::memoize($fn, null, $cache);
$memo(1);
// 1
$memo(2);
// 4
$memo(3);
// 9
$this->array($cache)->isEqualTo([1 => 1, 2 => 4, 3 => 9]);
// it should throw an InvalidArgumentException if cache is not suitable
$this->exception(function () {
$cache = "hello";
_::memoize(function () {
}, null, $cache);
})->isInstanceOf('\\InvalidArgumentException');
}