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From: rb@cci632.UUCP
Newsgroups: net.lang
Subject: Re: Extensibility (Re: RRe: What's so good about FORTH?
Message-ID: <211@cci632.UUCP>
Date: Fri, 11-Jul-86 20:56:08 EDT
Article-I.D.: cci632.211
Posted: Fri Jul 11 20:56:08 1986
Date-Received: Wed, 16-Jul-86 03:28:13 EDT
References: <201@pyuxv.UUCP> <3700003@uiucdcsp> <132@vaxb.calgary.UUCP> <152@cci632.UUCP> <770@ucbcad.BERKELEY.EDU> <473@astroatc.UUCP>
Reply-To: rb@ccird1.UUCP (Rex Ballard)
Organization: CCI, Rochester Development, Rochester, NY
Lines: 41
Keywords: FORTH, threaded-code
Summary: How to get "object oriented forth".

In article <473@astroatc.UUCP> philm@astroatc.UUCP (Phil Mason) writes:
>In article <770@ucbcad.BERKELEY.EDU> faustus@ucbcad.BERKELEY.EDU (Wayne A. Christopher) writes:
>>Perhaps this discussion is bothering some people, but I have another
>>question about forth for the gurus on the subject . . .
>
>This IS net.lang. This is what this news-group is for. Now if we were on
>net.women . . .      
>
>As you were saying ...
>>The major
>>advantage of C (as I see it) over Fortran, etc is the possibility of
>>defining structures and abstract types.  Does forth have anything
>>comparable, or are there any forth paradigms that make this easy?  
>
>Yes, there are the Builds(Create) - Does words that can define a new class
>of words. The Builds(Create) words allocates the proper space and does
>any necessary initialization. Does describes the run-time behavior of the
>new word. A short time ago, a gentleman posted a 16 line Forth implementation
>of Pascal record structure types on net.lang.forth. You can very succinctly
>describe any data structure you want either from scratch with Builds(Create)-
>Does or a set of tools that use them.
>
>>Also, what sort of position does forth take in the spectrum with functional
>>programming on one end and object-oriented programming on the other?
>>It seems to me that (like C) forth doesn't really try to deal with this
>>problem...
>

If you write your various operations, then build a "class switch" word,
then use the : Class builds (size) alloc does class_funtion ; you have
a class which will implicitly define its own object (like new).

By creating "stack constant" operators such as : Print 1 ;

You can say

Class object
Print object

And your object, of whatever type would be printed.
Cute? :-).