"David Benbennick" <[EMAIL PROTECTED]> writes: > On 10/17/07, John Meacham <[EMAIL PROTECTED]> wrote: >> Oops, sorry, the version I posted was an intermediate one that had a >> different addition algorithm. here is a better one that fixes that issue: >> >> Zero + y = y >> Sum x n1 + y = Sum x (y + n1) >> >> note that it alternates the order in the recursive call, interleaving >> the elements of the two arguments. > > Thanks. > > Have you thought at all about how to make "maximally lazy" Naturals? > For example, a data type that can answer True to both > > genericLength (1:undefined) + genericLength (1:2:3:4:5:6:undefined) > (6 :: > Nat) > > genericLength (1:2:3:4:5:6:undefined) + genericLength (1:undefined) > (6 :: > Nat) > > Is that a desired feature?
It may be desirable, but it's not lambda definable, so you'd have to use concurrency to acheive it. -- Jón Fairbairn [EMAIL PROTECTED] _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
