Since someone mentioned it, how slower is PUC Lua in respect to LuaJIT? Compromisingly slower? Are there metrics out there or is it a relatively subjective feeling?
Though luajit has gotten even more optimisations since that was done.
That said, I rarely find my code's performance is the bottleneck, and don't benefit from luajit. The guys that do are doing scientific computing (e.g. torch) or high performance networking (e.g. snabb)
This went under the radar for a while even though we had tons of traffic. Turns out PUC Lua is pretty fast on its own.
That really depends what you are testing for. For string ops is not the fastest. For recursive Fibonacci (inefficient) LuaJIT is faster than D and Lua is faster than Perl.
LuaJIT is at least 10x faster than all three.
Ruby faster than PUC Lua? That doesn't sound right. You're talking about Ruby MRI?
Not the original MRI, but YARV. For this particular program, the performance of different language interpreters is:
MRI (Ruby 1.8) < CPython 3.5 < CPython 2.7, PUC Lua 5.1/5.3 < YARV (Ruby 1.9/2.3) < LuaJIT -joff
There is a factor of ~5x between the slowest and fastest of these interpreters. LuaJIT with the JIT enabled is ~10x faster than even its own interpreter.
Unfortunately, as a Pythonista (although one whose paid work is mostly in JS these days), I can't imagine that happening in the Python community (not to our credit). Too much ego wrapped up in CPython.
YARV? No.
YARV is the current official Ruby interpreter - it replaced MRI in this role from Ruby 1.9 onwards.
(http://www.atdot.net/yarv/rc2006_sasada_yarv_on_rails.pdf page 15)