public static function shrink(callable $f, $roses)
{
$roses = FP::realize($roses);
if (empty($roses)) {
return self::pure(call_user_func($f));
} else {
return new self(call_user_func_array($f, FP::realize(FP::map(FP::method('getRoot'), $roses))), FP::rgen(FP::map(FP::partial([__CLASS__, 'shrink'], $f), self::remove($roses))));
}
}
/**
* creates a new generator that passes the result of this generator
* to the callable $k which should return a new generator.
*
* @param callable $k
* @return Generator
*/
public function bind(callable $k)
{
return $this->bindGen(function (RoseTree $rose) use($k) {
$gen = new self(function ($rng, $size) use($rose, $k) {
return $rose->fmap($k)->fmap(FP::method('call', $rng, $size));
});
return $gen->fmapGen(FP::method('join'));
});
}
