Hacker News Reader

congratulations, you've optimised a snippet that never ran – it was typed into the post form from memory

Premature optimization may sometimes be unadvisable, but in this case the optimized version uses half the memory, is two orders of magnitude faster, and doesn't let your users DOS you by triggering huge file reads on each request.

> uses half the memory

this is false

> two orders of magnitude faster

incorrect

> doesn't let your users DOS you by triggering huge file reads on each request.

I understood what you were trying to do on your first reply – "Prolly don't want to read the file on every request though" – no need to repeat yourself.

plese remember:

1. it's pseudo code, the optimisation is superfluous

2. it never ran, the optimisation is useless

Optimization is never useless. Even code that doesn't run is best written in a resource-effective manner.

unless the intent of the code is to demonstrate some implementation where the optimisations would be distracting

Reply on news.ycombinator.com