OpenEuphoria

Re: Faster lower() command

• Posted by Pete Lomax <petelomax at blueyonder.co.uk> Jan 21, 2007
• 554 views

jacques deschênes wrote:
> Why euphoria interpreter should create 5 or 6 * 1000000 long sequence?
>   return o + (o>='A' and o<='Z')*32 -- work as well with atom or sequence

tmp1 = (o>='A')  -- a 1000000 sequence of 0 and 1
tmp2 = (o<='Z')  -- a 1000000 sequence of 0 and 1
tmp1 = tmp1 and tmp2  -- ""                  ""
tmp1 *= 32            -- "" of 0 and 32
tmp1 = o+tmp1         -- "" (the result)
return tmp1

I get far more consistent results when called in a for loop, and I have noticed
tests like this tend to stongly favour whatever comes second, best to run them in
separate programs in the name of equality.
There might be a margin of say 5% for the 1-liner, but it is nothing like 4 or 5
times faster as you might at first expect. The more you play with the above two
code snippets, the more you realise they are essentially the same.

> I don't know how the loop is implemented inside euuphoria interpreter but
> there is place for optimization!

I could enter a long rant about why sequence ops are such a bad idea, but I
think I'll spare you today.

Chris Bensler wrote:
>Pete: peek() will accept peek({lp,0}) which will result in a null string
Thanks, I'll edit my copy of that routine.

Regards,
Pete