From lwall@netlabs.com Wed Aug 10 17:04:18 1994
Newsgroups: comp.lang.lisp,comp.lang.perl,comp.lang.tcl,comp.lang.clos
From: lwall@netlabs.com (Larry Wall)
Subject: Re: Unix tower of babble tcl/awk/perl -- why not just lisp?
Organization: NetLabs, Inc.
Date: Wed, 10 Aug 1994 18:43:52 GMT

In article <326q6t$3ct@crchh404.bnr.ca> tdoan@bnr.ca (Tuan Doan) writes:
:    Python also stresses correct indentation style.  As a matter of fact, like
: occam, the syntax of some of its statement require indentation.

Outlines have their place, and give at least the appearance of
organization.  But real life tends to be be a little more tangled
than that.  I doubt you write love letters in outline form.

The basic problem of outlines from a psychological point of view is
that they violate the Aristotelian notion that things should have a
beginning, a middle, and an end.  Implicit terminations confuse the end
of one thing with the beginning of the next.  You have to start
understanding the next thing before you can put the previous thing out
of your mind.  For instance, if at the end of one screen I see

	while something:
	    foo

I don't know whether the next screen is going to start with

	    bar
		
or with

	bar

But if I see

	while (something) {
	    bar;

then I know darn well that the next page is going to start inside
that block, and if I see

	while (something) {
	    bar;
	}

then I know it darn well isn't.

You won't find many dangling structures in Perl for this reason.  Lisp
also gets this right, though the typical Lisp indenting style throws
the advantage away.

Larry Wall
lwall@netlabs.com