From: Rich <rich@...>
Date: 2002-12-06T06:19:38+09:00
Subject: Re: [ANN] ratlast 0.1 -- embedded FORTH in Ruby

Mark,

    I'm not nocking ya and I don't have a clue about FORTH... so... why
would I use FORTH instead of Ruby?

    Where can I go to learn FORTH?

-Rich

----- Original Message -----
From: "Mark Probert" <probertm@nortelnetworks.com>
To: "ruby-talk ML" <ruby-talk@ruby-lang.org>
Sent: Thursday, December 05, 2002 1:57 PM
Subject: [ANN] ratlast 0.1 -- embedded FORTH in Ruby


>
> Rubyists,
>
> Later on today, I will be uploading the first release of
> ratlast to RAA.  You can get the system at
>
>    http://www3.sympatico.ca/mark.probert/download/files/ratlast_0_1.tar.gz
>
> (This is my home account which I don't have access to at work.
> I will upload the file around 19.00 EST.)
>
>
> *** What is ratlast?
>
> ratlast is an extension gives Ruby the power and flexibility of FORTH,
> using John Walker's ATLAST system.
>
> ATLAST is a F-83 style system that includes floating point
> and string primitives, as well as systems FORTH standards such
> as CREATE and DOES>.  It is very powerful, flexible, fast, and
> easy to extend.  On the fly compiling is trivial.
>
> Most of all, it is a -lot- of fun to use!
>
> *** Example
>
> Here is a little magic :-).  We create a linear equation ax+b and
> give it the name 'linear'.  For the example, we know the slope (3)
> and intercept (17) and the x varies.  We then evaluate the function
> and print the result.
>
> (For the FORTHists in the audience, the stack is 4-bytes wide for
> all integers, hence the 4 + ...)
>
> $ cat ex1.rb
> require 'Atlast'
> t = Atlast.new
>
> t.eval(": linear ( a b -- )  create swap , , does> dup >r @ * r> 4 + @ +
;")
> t.eval("3 17 linear aline")
> x = 1
> until x >= 10
>      t.eval("#{x} aline .")
>      puts "x=#{x} : 3x + 17 = #{t.capture[0]}"
>      x += 1
>      t.clear      # clear the capture buffer
> end
>
> *** Output
>
> $ ruby ex1.rb
> x=1 : 3x + 17 = 20
> x=2 : 3x + 17 = 23
> x=3 : 3x + 17 = 26
> x=4 : 3x + 17 = 29
> x=5 : 3x + 17 = 32
> x=6 : 3x + 17 = 35
> x=7 : 3x + 17 = 38
> x=8 : 3x + 17 = 41
> x=9 : 3x + 17 = 44
>
>
>
> -mark.
>
>
>