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From: worley@compass.com (Dale Worley)
Newsgroups: comp.lang.perl
Subject: Icon or Perl?
Message-ID: <1990Jul18.194940.6196@uvaarpa.Virginia.EDU>
Date: 18 Jul 90 19:49:40 GMT
Sender: mmdf@uvaarpa.Virginia.EDU (Uvaarpa Mail System)
Reply-To: worley@compass.com
Organization: The Internet
Lines: 25


   X-Name: Randal Schwartz

   Icon excels at what it was written for... munging strings, lists,
   structured data types, and so on.

One major feature is that Icon directly handles "backtrack and retry"
types of control flow, which is a real pain to code in a language that
doesn't have it built in.  Icon uses this to provide a truly awesome
pattern matching facility (much more general than regexps).  It can
also be used to provide a short and clear program to exhaustively
solve the "eight queens" problem.

Interestingly, both Perl and Icon by default pattern match against a
string supplied by the context.  In Perl, it's $_, in Icon, it is
declared by an operator (which I forget at the moment).

For you language hackers, Icon can be directly translated into Scheme
(pass around continuations to record resume points in operations that
can be resumed).  I don't think any less general control flow
mechanism can translate Icon directly.

Dale Worley		Compass, Inc.			worley@compass.com
--
Klein bottle for sale ... inquire within.