The Declaration Approach (was: Some thoughts on the 'reveal' operator)

[Mark S. Miller]

At 06:43 AM 10/22/99 , Douglas Crockford wrote:
>Perhaps
>
>     to foo(x) < booga(x) >
>
>         produces { booga(x) }
>
>and
>
>     to foo(x) { booga(x) }
>
>         produces { booga(x) null }
>
>The idea here is that the leakability of an outer block is determined by the
>delimiters of the block. The <> delimiters are probably a bad choice here
>because of confusion with GREATERTHAN, but the idea is that <> blocks are
>productive and {} blocks are not.

Good, I like the bracketing approach.  I also agree that angle brackets are bad, but if suitable brackets could be found, this might be the best thing.  However, just to clarify, E must expand to Kernel E, and Kernel E must be a subset of E.  Therefore, I think you wanted to say

     to foo(x) < booga(x) >

expands to

         to foo(x) < booga(x) >

and

     to foo(x) { booga(x) }

expands to

         to foo(x) <
             booga(x)
             null
         >

However, since we're agreed that angle brackets are bad, "reveal" remains the best concrete proposal.


         Cheers,
         --MarkM