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From: nowlin@isidev.UUCP
Newsgroups: comp.lang.icon
Subject: Re: RE: terrible code
Message-ID: <9103191156.AA24294@uunet.uu.net>
Date: 19 Mar 91 11:56:08 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Distribution: inet
Organization: The Internet
Lines: 52

In message <9103190300.AA10894@turing.cse.nau.edu> From: (Steve Wampler)
> } Out of curiousity (and because I like bizarre code), couldn't
> } the above be written:
> } 
> }     m := 0
> }     while m >:= *(s[i:j] ? =!l)
> }     return i + (0 ~= m)
> } 
> } instead?  (No, I haven't tried it, but it seems the same to me...)
> 
> Sigh.  Make that a <:=, not >:=.

Good reduction.  The only problem with this is that if someone were to
include an empty string in the list they're matching this solution would
fail even if it matched the empty string.  (I know...who cares!)  A simple
modification fixes that though.  I added enough to test this.  Look at an
earlier posting to see comments:

procedure main(args)
	s := "that begins this string"
	l := ["th","that beg","not close","","tha","begins t","that b","t"]
	write(longstr(l,s,6,12)) | write("nomatch")
	l := ["th","that beg","not close","tha","begins t","that b","t"]
	write(longstr(l,s,6,12)) | write("nomatch")
end

procedure longstr(l,s,i,j)
    ##### borrowed #####
    /s := &subject
    if \i then {
	if i < 1 then
	    i := *s + (i+1)
    }
    else i := \&pos | 1
    if \j then {
	if j < 1 then
	    j := *s + (j+1)
    }
    else j := *s+1
    ##### borrowed #####

    m := 0
    while m <:= *(p := (s[i:j] ? =!l))
    if /p then fail
    else return i + m
end

+-------------------------------------------------------------------------+
|  --- ---                                                                |
|   | S |  Iconic Software, Inc.  -  Jerry Nowlin  - uunet!isidev!nowlin  |
|  --- ---                                                                |
+-------------------------------------------------------------------------+