Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!crdgw1!sunbelt!eaker
From: eaker@sunbelt.crd.ge.com (Charles E Eaker)
Newsgroups: comp.lang.forth
Subject: Re: Merits of Forth
Message-ID: <17792@crdgw1.crd.ge.com>
Date: 21 Mar 91 22:55:51 GMT
References: <1991Mar21.192611.28487@src.honeywell.com>
Sender: news@crdgw1.crd.ge.com
Distribution: na
Organization: General Electric Corporate R&D Center
Lines: 33

In article <1991Mar21.192611.28487@src.honeywell.com> lowry@src.honeywell.com (Dave Lowry) writes:
>With all this discussion of the merits of Forth, I wonder if somebody
>could comment on the usefulness of a language that merrily accepts
>things like:
>
>: 1 2 ;
>
>resulting in:
>
>1 1 + . 4 ok

You need the language to tell you that : 1 2 ; is a stupid definition?
or to prevent you from stringing together lexemes into structures that
represent semantic nonsense? Every language allows any manner of
semantic blathering. Try teaching a first programming course in Pascal
or C.

Few languages can protect programmers from nonsense.  But very few even
allow you to express the kind of nonsense found in : 1 2 ; The
alternative is to introduce restrictions on what characters can appear
in a word's name and where they may appear in the name. If : 1 2 ; is
ruled out, so is : 1 1 ; Many of us would argue that the cure is
clearly worse than the disease. (Although the disease can be close
to fatal when FEED is accepted by the interpreter when the base is
hex, and the word named FEED is not, contrary to your expectations,
in the search order.)

The fact that Forth accepts kinds of nonsense that can't be expressed
in most other languages says nothing about Forth's usefulness.  It is
merely a side-effect of Forth's lack of restrictions on names.
--
Chuck Eaker / P.O. Box 8, K-1 3C12 / Schenectady, NY 12301 USA
eaker@crd.ge.com        eaker@crdgw1.UUCP       (518) 387-5964