OpenEuphoria

Re: Interesting Experiment With String/Sequence Slicing

• Posted by Derek Parnell <ddparnell at bigpond.com> Aug 21, 2001
• 428 views

Robert,
is the *ANY* chance (pretty-lease) that you might create an in-built version
of match and find that allows a starting offset index, similar to BASIC's
instr() function. Maybe somthing like ...

  findfrom(offset, look_for, look_in)
  matchfrom(offset, look_for, look_in)

I find myself frequently cutting and dicing slices, or doing ssllooww
searches because this functionality is missing. It would be so much faster
if these were in-built rather than Euphoria-written functions.

----- Original Message -----
From: "Robert Craig" <rds at RapidEuphoria.com>
To: "EUforum" <EUforum at topica.com>
Sent: Wednesday, August 22, 2001 2:00 AM
Subject: Re: Interesting Experiment With String/Sequence Slicing


> >
> Sam Lie writes:
> > i have ran the profiler and the bottle neck still
> > shows up when doing string slicing.
>
> I gather from your earlier private e-mail that you are reading huge
> strings from a file and running match() on them.
> Or perhaps the string *is* the whole file?
>
> Since match() starts at the beginning of a sequence,
> and stops when it encounters a match, I gather
> you are slicing the 50K strings to look for further matches.
>
> Try reading and searching one line at a time using gets().
> You won't be copying a huge string when you have a match,
> and you'll make better use of the Pentium on-chip cache,
> e.g.
>       object line
>       integer fn
>
>       fn = open("myfile.html", "r")
>       while 1 do
>             line = gets(fn)
>             if atom(line) then
>                 exit
>             end if
>             if match("foobar", line) then
>                 .....
>             end if
>       end while
>       close(fn)
>
> After doing the above, if you are still convinced that
> slicing is the culprit, you could write your own match()
> that locates multiple occurrences without slicing.
> (There may be an example in the mailing list archives.)
>
> Regards,
>    Rob Craig
>    Rapid Deployment Software
>    http://www.RapidEuphoria.com
>
> >
> >
>
>