From: Jordan Katz
Subject: replacing strings.
Date: Thu, 18 Apr 2002 02:35:48 +0000
Message-ID: <m3elhdu41n.fsf@underlevel.underlevel.net>

Hi,

  I'm looking for an easy (efficiency is not a factor) way to replace
  string x with string y in string z.  This is not homework (I take no
  CS classes) so I'm not looking for a detailed character by character
  way as sometimes seen in books but rather for the quick idiomatic
  way.  When I post I usually show my attempt at the problem but here
  I'm looking for ideas on where to start rather than corrections to
  my code.  I'd appreciate all suggestions on what functions to look
  at or where to start to do this, because I'm clueless on how to
  start writing this function.

Thanks a lot,
-- 
Jordan Katz <····@underlevel.net>  |  Mind the gap

• Re: replacing strings. Wade Humeniuk
• Re: replacing strings. Christopher C. Stacy

From: Wade Humeniuk
Subject: Re: replacing strings.
Date: Thu, 18 Apr 2002 04:03:21 +0000
Message-ID: <a9lg5d$pbb$1@news3.cadvision.com>

"Jordan Katz" <····@underlevel.net> wrote in message
···················@underlevel.underlevel.net...
> Hi,
>
>   I'm looking for an easy (efficiency is not a factor) way to replace
>   string x with string y in string z.  This is not homework (I take no
>   CS classes) so I'm not looking for a detailed character by character
>   way as sometimes seen in books but rather for the quick idiomatic
>   way.  When I post I usually show my attempt at the problem but here
>   I'm looking for ideas on where to start rather than corrections to
>   my code.  I'd appreciate all suggestions on what functions to look
>   at or where to start to do this, because I'm clueless on how to
>   start writing this function.

There seems to be two cases, where x and y are the same length and when x
and y are different lengths.  The CLHS section on sequences seems most
appropriate.

CL-USER 1 > (setf string "hello123world")
"hello123world"

CL-USER 2 > (search "123" string)
5
CL-USER 5 > (replace string "out" :start1 (search "123" string))
"hellooutworld"

CL-USER 11 > (setf string "hello123world")
"hello123world"

CL-USER 12 > (let ((position (search "123" string)))
              (concatenate 'string
                           (subseq string 0 position)
                           " "
                           (subseq string (+ position (length "123")))))
"hello world"

CL-USER 13 >

From: Christopher C. Stacy
Subject: Re: replacing strings.
Date: Thu, 18 Apr 2002 03:36:25 +0000
Message-ID: <u662pllty.fsf@grant.org>

You might start with SEARCH, SETF and SUBSEQ.