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From: dwp@willett.UUCP (Doug Philips)
Newsgroups: comp.lang.forth
Subject: Re: PUZZLES AND PROBLEMS
Message-ID: <1446.UUL1.3#5129@willett.UUCP>
Date: 2 Aug 90 02:10:55 GMT
References: <1429.UUL1.3#5129@willett.UUCP>
Organization: String, Scotch tape, and Paperclips.  (in Pgh, PA)
Lines: 67

In <1429.UUL1.3#5129@willett.UUCP>, W.BADEN1 [Wil] writes:

> The purpose of subroutines is to package "What to" whatever the language.  The
> level of a language is a measure of how much has already been piled up for
> you, or conversely how much you have to pile up to do what you want to do.  In
> this ordering Forth clearly stands between Asm and C.

Hmmm.  I don't quite follow this here.  I would be more inclined to put
C and Forth at about the same level.  If you look at the language itself
and not the libraries.  I say that because while PD or ShareWare versions
of Forth are pretty bare bones, so are most PD or ShareWare C's.  As a
side note, it tickles me to see the ratio of PD/ShareWare Forths to C's 
versus the ratio for commercial products.  Anyway, from the ads I've
seen, the libraries available for Forth are comparable to those available
for C.  The real issue is, I think, the language itself.  Both C and Forth
provide basic "machine" types.  C provides structures/unions which most
PD Forth's don't; I don't know if commercial systems do or not.  C and Forth
provide the same style of looping and branching constructs, with, perhaps,
the exception of C's "switch", but again, I don't know about commercial
Forth's.  C provides global, module and block scoping.  Forth has
vocabularies.  Commercial Forth's may have locals (like block scoping).
C is traditionally compiled, but interpreters are becoming available.
Forth is traditionally interpreted, but subroutine threading is often
available.  C defers I/O to the runtime library.  Forth has it built in.
C defers memory management to the runtime library.  Forth has some
memory management built in.  C often lets you escape to machine code
with "asm()" statements.  Forth has ;CODE.  C has separate compilation.
Forth has vocabularies, but that isn't really the same thing.  Forth's
ability to drop into assembly code allows one to interface with other
languages.  I don't know how common this is with commercial systems.
I think I hit all the main points (until I irrevocably send off this
message anyway!).  The point I'm trying to make is that although one
might technically rate C higher on the basis of the above comparison,
I would argue that Forth is not clearly between C and ASM.  I would
say that it is more more clearly close to C.

> All sufficiently powerful languages have this ability.  This is the way
> applications are programmed in every language.  What Forth shares with Lisp
> and APL is the ability to grow into your application.  (Tell me, does
> SmallTalk have this too?)

I've not written much SmallTalk, but the literature seems to support that
view.  Rapid prototyping, interpreted self-modifying system. etc.

> As an application is built, every component should be checked.  With
> conventional development this means that scaffolding must be rigged for each
> component.  This scaffolding, which may become much larger than the final
> appplication, is thrown away.  Forth's mode of development reduces and often
> eliminates scaffolding.

Forth is losing this advantage.  There are products available for
interpreting C code.  Often they are billed with the same advantages that
the Forth environment has, plus the advantage of "compiling" the production
version of the code to "recover" the traditional speed advantage.  Lisp,
Forth, Smalltalk, APL and probably others I don't even know about, all
provide a nice interactive environment for prototyping and development.
Forth is the only one (maybe APL too) that can do so in very spartan
quarters.  That environmental economy is a *second* order effect of the
Forth philosophy, not a *first* order one.  As resources become cheaper
Forth will have to rely more on its *first* order attributes in order to
retain/attain superiority or popularity.

-Doug

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