Re: What's right with FORTH and wrong with c.l.f.

pml540114@[EMAIL PROTECTED]
 wrote:

> Actually, I've been doing occasional work on a Forth variant with a
> different compiler/interpreter that doesn't even have that, but has a
> Reverse Polish naming approach. The basic idea, before syntactic
> sugar, is that it compiles left to right in the usual way, building up
> anonymous secondaries. Any unrecognised token terminates the current
> anonymous secondary and is assigned as its name, and a new anonymous
> secondary starts. At the end of the source string the final anonymous
> secondary is closed off and run. Before syntactic sugar, ANY source is
> valid!

Interesting! I wonder if John Doty has seen this. Or Chuck Moore.
There's a radical simplicity to it.

> This loses a lot of what most Forths are aiming for, like the other
> defining words and maybe even immediate words, but I was just
> testbedding something that doesn't need or want them anyway, so
> workarounds are good enough there. 

> For further details, see
> http://users.beagle.com.au/peterl/furphy.html.


> (One possible variant:
> terminate all anonymous secondaries with branches back to the
> beginning so they default to infinite loops, and provide a conditional
> return as the only essential explicit control construct.)
> P.M.Lawrence.

I'm troubled by what you call "false friends", commands that have the
same name as Forth commands but radically different actions. If you
implement it in Forth that looks like it invites problems, and it
shouldn't be too hard to make new names. But a quick look at your Pygmy
code did show new names.


It always seemed to me that Forth could be used like a functional
language, at least in talking-dog style. ("You complain that he doesn't
speak well, but it's remarkable he can talk at all.") Avoid variables
etc and you can mostly avoid side effects. Often composition of
functions is simple. If you don't mind strict evaluation then 

z = f(x);
y = z * z;

becomes

: f ( ? -- z )
  ??? ;

: y ( z -- z^2 )
   DUP * ;

: y(f)
   f y ;

And of course recursion is available etc.

But you're taking it a lot further.