Subject: Re: Midfunction Recursion
From: Erik Naggum <>
Date: 23 Oct 2002 17:34:33 +0000
Newsgroups: comp.lang.lisp
Message-ID: <>

* Nils Goesche
| Yes, tail recursion is easy to understand.

  It is the first time in this newsgroup, but I have heard from people who
  have taken Scheme courses various places who actually think recursion is
  merely a form of iteration.  It would be silly to just claim this without
  some evidence, but nobody has wanted to come forward to admit it when
  they suspected the consequences or even grew the prerequisite clue.

  Teaching iteration as a form of recursion is just plain wrong as people
  get it backward: recursion is a form of iteration.  It sounds too silly to
  be believable, but ask around, and more than our unwitting contributor
  here will effectively say this.  I blame this squarely on stupid teaching
  methods and silly languages that teach the wrong thing to people who are
  a little too eager to jump to conclusions.  But those people /abound/ and
  it is the responsibility of teachers /not/ to send their students across
  mine fields to sort them out the hard way.

  I think teaching tail recursion as something separate from recursion is a
  really bad thing.  If you cannot deal with reality when you want to teach
  iteration, send your students to a class on theatrical make-up and ask
  them to come back to you when they understand the difference between
  staged make-believe and the real story.

Erik Naggum, Oslo, Norway

Act from reason, and failure makes you rethink and study harder.
Act from faith, and failure makes you blame someone and push harder.