Re: Ruby?

[Luiz Henrique de Figueiredo <lhf@...>]

>My naive Lua implementation with the fixes did it in 3.51,
>adding the local dropped it to 3.00.

I ran the same tests in my machine in 4 versions and got these results:

1	2.52	100%	1.00
2	1.73	 68%	1.45
3	1.52	 60%	1.65
4	1.05	 41%	2.40

Version 1 is the original (fixed) by Bennett Todd:

%  cat 1
#!/usr/bin/lua

function myincr(n)
        return n + 1
end

x = 0
i = 0
while i < 1000000 do
        x = myincr(x)
        i = i + 1
end

print(x)

Version 2 adds "local" for x and i; version 3 adds "local" for myincr too;
and version 4 uses a "for" instead of a "while":

% diff 1 2
6a7
> local x,i

% diff 2 3
2a3,4
> local myincr
>

% diff 3 4
9c9
< local x,i
---
> local x
11,12c11
< i = 0
< while i < 1000000 do
---
> for i=1,1000000 do
14d12
<       i = i + 1

So, simple transformations can get a speedup of 2.4!
Of course, real scripts spend their time doing useful work and so these tests,
like all benchmarks, should be taken as whta they are: simple indications.
The only real test is your own script.
--lhf