From ...
From: Erik Naggum <erik@naggum.no>
Subject: Re: How to write implode and explode?
Date: 1998/10/13
Message-ID: <3117311418185126@naggum.no>#1/1
X-Deja-AN: 400792664
References: <362267F7.3474D25B@dowco.com>
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Organization: Naggum Software; +47 8800 8879; http://www.naggum.no
Newsgroups: comp.lang.lisp

* Josh Gardner <jgard@dowco.com>
| I'm stuck on a bit of a problem: I need to write an implode function -
| takes '(H e l l o) and gives back 'Hello. and I need to write an explode
| function - takes 'Hello and returns '(H e l l o)

  OK, so it's probably homework, yet here's what I'd do, but I'm certain
  that you won't be allowed to hand this in, anyway, so it's safe to give
  you this "answer".

(defun explode (symbol)
  (map 'list (lambda (character) (intern (string character) #.*package*))
       (symbol-name symbol)))

(defun implode (list)
  (intern (map 'string #'character list) #.*package*))

#:Erik