Re: Lua Performance, IO / Regexp

[Hans Hagen <pragma@...>]

gary ng wrote:
> --- Hans Hagen <pragma@wxs.nl> wrote:
>
> > Mariano Kamp wrote:
> >
> > >   Any ideas and hints what I can do to make things
> > faster and/or prettier?
> >
> > - lpeg: much faster than string match
> > - no metatable: less code and less function calls
> > (not faster here)
> > - binary read: no need to parse line endings in io
> >
> > - the lpeg can probably be made faster (no time to
> > look into it now)
> I can confirm that lpeg is much faster than hand coded
> string match.

btw, when making lpegs it helps a bit if one knows what to expect

0.297: parser = ((1-complete)^0 * complete * (1-newline)^0 * newline)^0 
       0.295: parser = (complete * (1-newline)^0 * newline + 1 )^0 
           0.312: parser = (complete + 1)^0 


sometimes the last method is faster, but not here

> However, my experience is that lua's sort() function
> is noticeably slower than python's. I am not sure how
> it compares with ruby or perl.

maybe the overhead of the function call

anyhow, in this case (large amount of data) the time spend on sort seems 
to be small

Hans

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