Is Moose really this slow?

Question

I recently downloaded Moose. Experimentally, I rewrote an existing module in Moose. It seems to be convenient way to avoid writing lots of repetitive code. I ran the tests o

Answer 1

See Moose::Cookbook::FAQ:

I heard Moose is slow, is this true?

Again, this one is tricky, so Yes and No.

Firstly, nothing in life is free, and some Moose features do cost more than others. It is also the policy of Moose to only charge you for the features you use, and to do our absolute best to not place any extra burdens on the execution of your code for features you are not using. Of course using Moose itself does involve some overhead, but it is mostly compile time. At this point we do have some options available for getting the speed you need.

Currently we provide the option of making your classes immutable as a means of boosting speed. This will mean a slightly larger compile time cost, but the runtime speed increase (especially in object construction) is pretty significant. This can be done with the following code:

MyClass->meta->make_immutable();

We are regularly converting the hotspots of Class::MOP to XS. Florian Ragwitz and Yuval Kogman are currently working on a way to compile your accessors and instances directly into C, so that everyone can enjoy blazing fast OO.

On the other hand, I am working on a web application which using Dancer and Moose. Because the application is running as an HTTPD daemon, none of this is really relevant once the server is initialized. Performance seems more than adequate for my requirements on limited hardware or virtual servers.

Using Moose and Dancer for this project has had the added benefit that my small demo application shrank from about 5,000 lines to less than 1,000 lines.

How much stuff you want your app to depend on is one of those trade-offs you have to consider. CGI apps are made more responsive by limiting dependencies.