OpenEuphoria

Re: Faster lower() command

• Posted by jacques deschênes <desja at globetrotter.net> Jan 20, 2007
• 551 views

Hi Jesse,
As I was quite skeptic I made my own test here

function lower1( sequence x )
    integer c
    for i = 1 to length(x) do
        c = x[i]
        if c <= 'Z' then
            if c >= 'A' then
                x[i] = c + 32
            end if
        end if
    end for
return x
end function

function lower(object o)
  return o + (o>='A' and o<='Z')*32 -- work as well with atom or sequence
end function


atom t
constant txt=repeat('A',1000000)
sequence l

t = time()
l = lower1(txt)
? time()-t
t = time()
l = lower(txt)
? time()-t

on my laptop
lower1() give .12sec
lower()  give .09sec
As I expected the for loop is slower than the interpreter internal loop.
I can't figure how lower1() can be faster on your machine.

regards,
Jacques Deschênes




Jesse Adkins wrote:
> 
> jacques deschênes wrote:
> > 
> > here is the power of euphoria
> > 
> > }}}
<eucode>
> > function lower(object o)
> >   return o + (o>='A' and o<='Z')*32 -- work as well with atom or sequence
> > end function
> > </eucode>
{{{

> > 
> > 
> > regards,
> > Jacques D.
> 
> I'm well aware of that command, since it's what's in place already. The
> command that I put up for display processes a sequence much faster than the
> current code for lower(). A test I ran, with all letters in caps, ran about
> 
> twice as fast as the current code.
> 
> I kept the original code for doing atoms, since the guru.ex code doesn't work
> so well with atoms for some reason
> 
> I'm hoping the code I posted earlier could become part of Euphoria some day,
> 
> despite the fact that it's a good deal larger than the current lower()
> command.
> 
> -- Jesse Adkins.