Re: [stack] Programming Puzzle

Well done!

I made a mistake with my Joy words: "cat" is supposed to be "concat".

I did include "unit" in my list, so the construction is valid according to
the rules I set out.
I also believe in Joy you can define unit as "[] concat", am I correct?

Second puzzle: do the same without using the name of the function in the
definition.

Does any know of smaller constructions?

- Christopher


On 5/16/07, Joshua Shinavier <[email protected]> wrote:
>
>   Well, this seems to work:
>
> DEFINE mywhile ==
> swap [dup] dip swap
> [[dup dip] dip mywhile] cons cons
> []
> ifte.
>
> E.g.
>
> 1 [2 *] [dup 100 <] mywhile.
>
> yields 128. However, it uses cons, which is not in your list. I think I
> should be able to construct cons like so:
>
> DEFINE cons == [unit] dip concat.
>
> ...if only knew how to construct unit :-)
>
> Josh
>
> On 5/16/07, Christopher Diggins <[email protected] <cdiggins%40gmail.com>>
> wrote:
> >
> > For your amusement here is a fun programming puzzle:
> >
> > Define a while loop that takes a loop body and termination predicate
> > in Joy using only the following combinators:
> >
> > "ifte","cat","swap","dup","pop","i","dip" and "unit"
> >
> > Cheers,
> > Christopher
> >
> >
>
> [Non-text portions of this message have been removed]
>
> 
>


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