public function testRun()
{
$ret = runWriter(tell("a")->bind(function ($_) {
return Monad\Writer::ret(1);
}));
$this->assertEquals([1, "a"], $ret);
$ret = runWriter(tell("a")->bind(function ($_) {
return ret(1);
// Any#cast => Writer
}));
$this->assertEquals([1, "a"], $ret);
$ret = runWriter(tell("a")->bind(function ($_) {
return tell("b");
})->bind(function ($_) {
return ret(2);
}));
$this->assertEquals([2, "ab"], $ret);
$ret = runWriter(tell("a")->bind(function ($_) {
return tell("b");
})->bind(function ($_) {
return ret(2);
})->bind(function ($a) {
return ret(3);
}));
$this->assertEquals([3, "ab"], $ret);
$ret = runWriter(ret(2)->bind(function ($_) {
return tell("a");
})->bind(function ($_) {
return ret(2);
}));
$this->assertEquals([2, "a"], $ret);
}
private function searchTree(callable $f, Tree $tree)
{
if ($tree instanceof EmptyTree) {
return mzero();
}
if ($f($tree->value)) {
return $this->searchTree($f, $tree->left)->mplus(ret($tree->value))->mplus($this->searchTree($f, $tree->right));
} else {
return $this->searchTree($f, $tree->left)->mplus($this->searchTree($f, $tree->right));
}
}
public function testMonoid()
{
$ret = ret('ab')->mappend(ret('cd'));
$this->assertInstanceOf('Laiz\\Func\\Any', $ret);
$this->assertEquals('abcd', $ret->cast(''));
$this->assertEquals(['ab', 'cd'], $ret->cast([]));
$this->assertEquals(Just('abcd'), $ret->cast(Nothing()));
$this->assertEquals(['ab', 'cd', 'x'], $ret->mappend(['x']));
$this->assertEquals(Just('abcdx'), $ret->mappend(Just('x')));
$e = mempty();
$s = 'str';
$a = ['arr'];
$m = Just('m');
$this->assertEquals('str', mappend($e, $s));
$this->assertEquals('str', mappend(mappend($e, $s), $e));
$this->assertEquals(['arr'], mappend($e, $a));
$this->assertEquals(['arr'], mappend(mappend($e, $a), $e));
$this->assertEquals(Just('m'), mappend($e, $m));
$this->assertEquals(Just('m'), mappend(mappend($e, $m), $e));
}