From: nanothermite911fbibustards on
Very EDUCATIONAL VIDEO
http://www.youtube.com/watch?v=wzr_hRsSuGM&feature=related

On Jun 22, 1:40 pm, Cecil Westerhof <Ce...(a)decebal.nl> wrote:
> Op dinsdag 22 jun 2010 19:28 CEST schreef Pascal J. Bourguignon:
>
>
>
> >>> this (while (re-search-forward ...)) loop modifies the line for each
> >>> occurence of the regexp, replacing it with (substring substitute-str 0
> >>> match-length), which is a different replacement string in general.
>
> >> Why? I would think the replacement string is the same. (When using
> >> single byte characters.)
>
> > With:
>
> > substitute-str = "Abcdef" ; initally
> > start-match    =  4
> > end-match      = 12
> > match-length   =  8
>
> > substitute-str will become "AbcdefAbcdef",
> > and   (substring substitute-str 0 match-length)        = "AbcdefAb"
> > while (substring substitute-str start-match end-match) = "efAbcdef"
>
> I made a stupid mistake. It did not show because I only changed a
> substring at the start of the line. Better code is at:
>    http://www.decebal.nl/guile/sources/substituteExpression.scm
>
> --
> Cecil Westerhof
> Senior Software Engineer
> LinkedIn:http://www.linkedin.com/in/cecilwesterhof