public function testAppend()
{
$m = new Func\Unit();
$m = mappend(new Func\Unit(), new Func\Unit());
$this->assertEquals(new Func\Unit(), $m);
$this->assertEquals(new Func\Unit(), mappend($m, mempty()));
$this->assertEquals(new Func\Unit(), mempty()->mappend(mempty())->mappend($m));
}
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), $e));
}
public static function ret($a)
{
return new Instance($a, mempty());
}