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On 16/02/2011 17:16, Mike Pall wrote:
Rule #437: Never hoist out constants (if possible)!

Always write constants inline, otherwise they are treated as
variables, which generates worse code. And, yes, even plain Lua is
able to fold 1/5 into a constant. It's important to write these
unambiguously -- FP arithmetic is not associative!

Good to know, but bad programming practice from a formal point of view. :-)
I always recommend to beginners in programming to replace magic numbers with constants, for readability and consistency. I understand that speed optimizations sometime have to break these nice rules (like manual loop unrolling and such).

It would be nice, perhaps, if Lua had a way to define true, efficient constants.
(Yes, that's another bag of worm. Perhaps if someone want to comment on my remark, a new thread should be started...)

Philippe Lhoste
--  (near) Paris -- France
--  --  --  --  --  --  --  --  --  --  --  --  --  --