Newsgroups: comp.lang.misc
Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!lavaca.uh.edu!menudo.uh.edu!sugar!ficc!peter
From: peter@ficc.ferranti.com (Peter da Silva)
Subject: Re: Dynamic typing (part 3)
Message-ID: <L-2A3G2@xds13.ferranti.com>
Reply-To: peter@ficc.ferranti.com (Peter da Silva)
Organization: Xenix Support, FICC
References: <730@optima.cs.arizona.edu>
Date: Mon, 18 Mar 91 18:03:24 GMT

In article <730@optima.cs.arizona.edu> gudeman@cs.arizona.edu (David Gudeman) writes:
> In article  <-B0A9_3@xds13.ferranti.com> Peter da Silva writes:
> ]That's because "real exp(real);" is programmed into everyone's head. If
> ]you have "complex y;" then "y <= 0;" is a syntax error.

> That's the point!  If you _don't_ write "complex y", and somewhere you
> have "y <= 0", then you know that y is not complex.  There is no
> pressing reason why you should have to write "real y" in most cases.

But if you don't know that y is complex, you don't know if "y <= 0" is
legal or not... working code or a bug. The only reason you can get away
with this in mathematics is everyone has had a bunch of Fortran-style'
default typing rules programmed into their head in college. And even so,
different mathematical languages disagree and you have to introduce people
to these new typing rules...
-- 
Peter da Silva.  `-_-'  peter@ferranti.com
+1 713 274 5180.  'U`  "Have you hugged your wolf today?"
