Re: [stack] function/object ambiguity + quotation alternative

On Feb 27, 2009, at 6:00 PM, Stevan Apter wrote:

> everything on the stack is a noun, everything on the queue is a verb.
> so we can rewrite your reduction, without ambiguity, as stack | queue:
>
>          | 2 [dup] first
>  2       | [dup] first
>  2 [dup] | first
>  2 dup   |

Indeed you can. Or you can rewrite it without ambiguity using an  
explicit stack.

The trouble is that both approaches make it impossible to reduce in an  
arbitrary order and at arbitrary levels. For example, I'd like to be  
able to do the following:

    1 2 3 + [[dup] first] [swap] first 5 2 +
    1 2 3 + [`dup] [swap] first 5 2 +
    1 2 3 + [`dup] [swap] first 7
    1 2 3 + [`dup] `swap 7
    1 5 [`dup] `swap 7

This is not possible if you use an explicit stack/queue for your  
reduction. You need to make sure each step in the reduction is itself  
a valid program.

- John