From: Paul Brannan <pbrannan@...>
Date: 2002-10-26T03:44:04+09:00
Subject: Re: How come true, false don't support <=> (comparison) operator?

On Sat, Oct 26, 2002 at 03:18:12AM +0900, Marcin 'Qrczak' Kowalczyk wrote:
> I find 'false < true' in all languages I know. Do you know any where
> it's otherwise?

It is true in languages that use 0 for false and 1 for true.  Python,
Perl, C, and C++ fall into this category.  There are probably countless
others.

I don't think it is not true in Smalltalk:
  [pbrannan@zaphod tmp]$ gst -Q
  st> (0 < 1) printNl !
  true
  st> (False < True) printNl !
  Object: False error: did not understand #<
  False class(Object)>>#primError:
  MessageNotUnderstood(Exception)>>#defaultAction
  [] in Exception class>>#coreException
  MessageNotUnderstood(Signal)>>#activateHandler:
  MessageNotUnderstood(Exception)>>#signal
  False class(Object)>>#doesNotUnderstand:
  UndefinedObject>>#executeStatements

Mzscheme doesn't like to compare true and false with < either:

  [pbrannan@zaphod tmp]$ mzscheme
  Welcome to MzScheme version 201, Copyright (c) 1995-2002 PLT
  > (< 0 1)
  #t
  > (< #f #t)
  <: expects type <real number> as 2nd argument, given: #t; other arguments were: #ifdef

Paul