Overcoming Swift Resistance Explored

This post is a response to David Owens' Swift Resistance Explored post.

First I want to acknowledge that Swift Debug builds are hideously slow. This isn't news to me or anyone who has seen my talk on Swift optimisation. To be clear this is a problem which Apple have said that they are working on but I still don't think it is an absolute block on any real development because there are fairly simple workarounds.

If you want to see the code under discussion it is all in my repository here with a log of my development. The first commit is the Zipfile that David made available in his blog post, the rest is my testing and development of the Swift version.

These are my performance figures (for 100 runs so it isn't directly comparable to David's):




0.077 (1.8)

0.042 (1)


0.38 (9.1)

13.7939 (327)