Gerhard Fiedler wrote:
>> Personally I think if you really want to optimise a processor to
>> execute high level code more efficiently then it needs an evaluation
>> stack (kind of like FORTH) [...]
>
> FORTH again... shouldn't it have had more success? :)

It had its chance and didn't emerge as a winner for good reason I think.
Back in the early 1980s I thought Forth might be a reasonable solution for
field or customer programmability in some embedded systems.  I even wrote a
few Forth interpreters, one on a general purpose computer for testing and
investigating concepts, and one in a display controller box.  Forth in the
box did exactly what it was intended to to.  It took remarkably little
memory to hold programs for doing math on coordinates, dealing with input
devices, etc, and the speed was adequate enough.

Then I tried to write some more complex programs.  I got them to work and
they worked well, were fast enough, and took little memory, but were a real
pain to write.  It was far more difficult to write good Forth programs than
I had imagined.  The company finally decided, and I agreed, that Forth was
just too difficult even for expert programmers, that making it available in
the product would cost way more in support than any additional revenue
gained by having user programming capability.

One place Forth-like concepts survive today is in PostScript.  I think that
works because all the benefits of Forth are still there, but humans don't
write PostScript.  Forth is actually not that hard a language to compile to,
especially when you're not trying to do arbitrary computations and are just
describing the layout and other specifics of a document.

I did manually write some PostScript once to support a reasonably compact
image file format in EPS (encapsulated PostScript).  Most of the image file
was compressed data for the PostScript program.  The program would maximally
scale and center the image on the page and decompress and print it.  Once
again, that relatively simple program took much longer to write than it
would have in a more traditional language.  It did work very nicely though.
Our EPS image files were not much bigger than ordinary image files, and a
lot smaller than everyone else's EPS image files.  Apparently nobody else
back then thought of using the programmability of PostScript to decompress
image data stored in the same file.


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