Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!samsung!gem.mps.ohio-state.edu!sunybcs!rutgers!cmcl2!acf5!sabbagh
From: sabbagh@acf5.NYU.EDU (sabbagh)
Newsgroups: comp.lang.forth
Subject: Re: Forth in C (was Re: Forth from scratch)
Message-ID: <930@acf5.NYU.EDU>
Date: 15 Nov 89 16:58:00 GMT
References: <4839@sdcc6.ucsd.edu> <2570@fai.UUCP> <4969@sdcc6.ucsd.edu> <8630@medusa.cs.purdue.edu> <21215@uflorida.cis.ufl.EDU> <8637@medusa.cs.purdue.edu>
Reply-To: sabbagh@acf5.UUCP ()
Organization: New York University
Lines: 38

In article <8637@medusa.cs.purdue.edu> bouma@cs.purdue.EDU (William J. Bouma) writes:
>   [stuff deleted]
>   Forgetting about C, what makes forth different from common-lisp? In
>   CL one has an interpreter, and can create new control structures on
>   a whim. Further, they look exactly like the rest of the language,
>   just as they do in forth. Forth is definitely not unique as a 
>   language in being extensible.

The _major_ difference between forth and Common Lisp, from a language
design point of view, is that Forth has a parameter stack and LISP does
not (so I seem to agree with you). In LISP terms, this implies that
the arguments to a procedure are evaluated _before_ the procedure is
evaluated; in LISP the procedure definition (i.e., def vs. defun vs.
ndefun, etc.) determines the evaluation its arguments.

There are, hwoever, operational differences, namely that Forth is
_smaller_ than common Lisp and was originally designed to accomplish
different things.  This makes it a lower level language in some
ways.

To add to the "Forth written in C debate" I wish to point out that,
in UNIX, it is not _possible_ to write Forth (in either C _or_
assembler !!!) that can allow the user to write definitions in the
native machine language (ie.e., assembler).  THis is because the
the "text space" (the segment of memory that holds the executable
code image) is defined to be _read-only_.  There may be a way
around this if you achieved a sufficiently high level of UNIX wizardry
and have the right priviledges :-).


Hadil G. Sabbagh
E-mail:		sabbagh@csd27.nyu.edu
Voice:		(212) 998-3285
Snail:		Courant Institute of Math. Sci.
		251 Mercer St.
		New York,NY 10012

186,282 miles per second -- it's not just a good idea, it's the law!