[ruby-talk:20454] Re: Backwards language

On 28 Aug 2001 10:20:20 +0900, Stephen White wrote:
> On 28 Aug 2001 07:57:31 +0900, Sean Middleditch wrote:
> > Oh.  ::sigh:: another language added to the growing stack of languages I
> > need/want to learn now.  Was Algol that highly used of a language?  I've
> > not heard much about it.
> 
> It's more valuable to learn families of languages than specific
> languages. If you choose to learn something Algol family of languages,
> you'll have a fair idea of what Algol's about. Studying specific
> languages within the family is more useful for seeing implementation
> tradeoffs and the effects of emphasising one facet over another.
> 

Understood.  I am attempting to write a small language, though -
learning implementations and such is quite a bit useful to me.  ^,^

> The most valuable language I ever learned, even though I can hardly
> write a loop in it these days, was Forth. It's truly amazing to see so
> much done with so little - highlighting the power of introspection and
> direct access to language internals. The power of "DOES>" is truly
> phenomonal - allowing the programmer to switch between compilation and
> interpretation in mid-stream.
> 

Wow.  I'm feeling denser every e-mail on this topic I get.  I don't
think I've ever even heard of Froth.  At least Algol I'd heard of.

> This is how the Forth word   ."   (to print a string) was implemented -
> the interpreter sees   ."   , then starts feeding raw program code
> directly to the program itself. The    ."   word happens, in this
> instance, to just output everything it gets until another " is reached.
> There's nothing to stop this string from being parsed any other way, so
> each command could have custom syntaxes as parameters. The language
> could be, and was, written in itself, outputting direct to bytecode
> while the programmer typed - there was no interpretation or compilation
> pass. There has never been a simpler and more elegant implemetation of
> eval than this!
> 

That certainly is interesting, but I see a few problems arising...

> This flexibility came at a price - the more this facility was used, the
> harder it is for someone else to pick up the code and understand what's
> happening. This, I think, was the nail in Forth's coffin (along with its
> RPN)- but what a coffin! It occurs to me that writing for a Forth stack
> machine, with an embedded Forth language to create more machine on
> demand, could be more interesting than the current bytecode machine.
> There's no speed issue either, as Forth machines are blindingly fast.
> 

Oh, and look, there the problems are.  ^,^  Hardware for running Froth?
You know, sometimes I *hate* having been born so late.  

> Back to the topic... My list of languages to know:
> 
>   An early assembler designed for human programmers (eg, one of: Z80,
> 6502, 68030, VL80C010) to understand CPUs
>   C for compatibility with other programmers, and to see how higher
> level abstractions can layer over the top of assembler
>   Forth to see how a more complex machine model (stacks instead of
> registers) leads to far greater flexibility.
>   Ruby for a human oriented language that a computer can handle.
> 

Just 4, hmm?  ^,^  I'm not sure what my list would look like if I put it
together, but I know it'd be bigger than that.  Why, I don't know.  half
the language I've bothered to learn I never use.  I should try putting
together a list like that, of languages I would recommend, then
individually analyze each item on the list and determine why I added it,
and if it should stay.

No, maybe I shouldn't, because then I'd likely realize how many days of
my life I spent learning useless languages.  ^,^

> Then a few other ones to a lesser degree, eg, "sh" for its concept of
> piping and building quite interesting little scripts by joining programs
> together, Prolog to find out how many times you can throw up in a row
> without fainting, BASIC for the crack cocaine of languages, Logo to see
> the program itself in a graphical manner, and so on.
> 

Logo?

> What's nice about Ruby is that it takes more of the best while remaining
> conceptually small. It doesn't have all of them, but perhaps the use of
> one great feature would make it more difficult to use the other great
> features...
> 

Yes, I definitely like Ruby.  Again, though, I just wish I wasn't so set
in C/C++.  I keep trying to do things "the wrong way" in Ruby.

> Now I think I'll go off and play with writing Forth in Ruby. :)
> 
>