/**
* Adds an operation to a stream.
*
* @param string $operation
* @param mixed $args
* @param Stream $stream
* @return Stream
*/
protected static function apply($operation, $args, $stream)
{
if ($stream->type == 'Error') {
return Stream::of(Error::of("Could not apply {$operation} to {$stream->type}", $stream->data));
}
if (!Stream::canApply($operation, $stream->type)) {
$data = toString($stream->data);
return Stream::of(Error::of("Could not apply {$operation} to {$stream->type}({$data})"));
}
return Stream::with($stream->data, Stream::optimize(append(['name' => $operation, 'args' => $args], $stream->operations)), Stream::returnOf($operation, $stream->type));
}