Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!sun-barr!ames!lll-winken!uunet!yale!Duchier-Denys
From: Duchier-Denys@cs.yale.edu (Denys Duchier)
Newsgroups: comp.emacs
Subject: Re: apply, mapcar, lack of setenv
Keywords: Emacs-lisp, hacking, environment
Message-ID: <62353@yale-celray.yale.UUCP>
Date: 2 Jun 89 15:21:13 GMT
References: <CSUWN.89Jun2041413@orchid.warwick.ac.uk>
Sender: root@yale.UUCP
Reply-To: Duchier-Denys@cs.yale.edu (Denys Duchier)
Distribution: comp
Organization: Computer Science, Yale University, New Haven, CT 06520-2158
Lines: 16
In-reply-to: csuwn@cu.warwick.ac.uk (Max)

(defun reduce (fun val lst)
  (while lst (setq val (funcall fun cal (car lst)) lst (cdr lst)))
  val)

(reduce (function (lambda (x y) (or x y))) (mapcar <your-function> <your-list>))

(reduce '* 1 '(1 2 3 4 5)) => 120 ;(i.e. 5!)

Also check cl.el for functions: some, every, notany, notevery

if <your-function> has no side effects: (some <your-function> <your-list>)

you need to define MAINTAIN_ENVIRONMENT in order to get all the
environment goodies like setenv.

--Denys