Re: [stack] the concatenative wikipedia article

On Jan 2, 2009, at 9:18 AM, Robbert van Dalen wrote:

> i do agree with john (nowak) that - if concatenativity is defined to
> be purely syntactic - it would include too many (non-interesting)
> languages.
>
> however, the syntactic standpoint does *exclude* a whole bunch of
> useful languages such as c(++), java, haskell,etc, that are not
> concatenative.

So would the category of all languages that use 'car' and 'cdr' to  
take the head and tail of a list. Such a category would basically mean  
Lisp and derivatives, but the definition of the category itself  
wouldn't let us say anything useful. I think that's the danger with  
your definition: It allows the things we want to allow, but doesn't  
let us say anything about them.

> and what about forth? surely, we don't want forth to be excluded!

I don't think the definition Chris proposed would necessarily exclude  
Forth. If you think there's an issue with parse words, perhaps there's  
some way to alter the definition?

> - not all terms in enchilada are functions
> - therefor, the juxtaposition of functions doesn't always denotes
> function composition

Enchilada is what I'd call a postfix term rewriting language. I don't  
think I'd consider it concatenative due to the presence of lambdas.  
Discussions in the past have indicated that lexical scope and  
substitution are not compatible with concatenativity. For example,  
given the expression '{a b=a b +}', I cannot define 'f' to be 'b +'  
and then say '{a b=a b +} == {a b=a f}'.

- John