SineSwiper/grm — comment on commit b8a50f6fbf6ad6738092db8e1f7dce771a574236
File: MapGen/Generator/Basic.pm line 127
By jettero:

Are you sure this is actually faster than the original i-j loop that was below? I'd be pretty surprised about that. I've never seen map generation take long enough to matter, so I'm not sure I really have any idea how long it actually takes. Your maps must be quite a lot larger than mine. I'm particularly interested in the @{ [ blarg ] } syntaxes. It seems like that'd be computational expensive just to avoid a couple extra lines of code. It's possible that modern Perls optimize it away, but I've never tested it personally.

Regardless of all that, my real concern is that this still works roughly the same. Faster, good. Different, bad. If it works a lot differently, then I'd say it should probably be a separate generator … say FastSparseAndLoops rather than SparseAndLoops. I mean to test that later, but none of my tests run because the options on my code don't work (see above).