Re: [stack] unary functions from X to Y?

----- Original Message ----- 
From: "William Tanksley" <[email protected]>
It would be
> perfectly possible to add a function to Forth to append a new return
> address to the bottom of the stack; it would be a total function change
> to make XY treat functions as opaque.

in XY, a quotation is made opaque by enclosing it with `.  this turns a
quotation into a function atom.  i added enclose/disclose because (if you
recall) i wanted to be able to build and manipulate trees of programs.
but if trees and programs are both quotations, it isn't possible to 
know purely on the basis of type when descent has reached a program.
this may seem too farfetched to bother about, but i do it quite often.

> 
> I think the basic lesson is that Forth and XY are doing the same thing,
> but using different models of function transparency.
> 
> -Wm
> 
> 
>