[Haskell] Re: Context of a pattern variable [ERRATA]

12 Jan 2005


      Below are corrections of embarassing mistakes in my examples, pointed out by
Wolfram and Stefan Holdermans.

On Tue, Jan 11, 2005 at 11:12:04PM +0100, Tomasz Zielonka wrote:
...
before:
case t of
      (x, y, z) -> (x, y, z+1)
after:
case t of
      (_, _, ctx @> z) -> ctx z
(_, _, ctx @> z) -> ctx (z+1)
...
BTW, I already see some problems with this syntax. For example, this code
case t of
      (x, y, (a, ctx @> Just z)) -> ctx z
wouldn't be equivalent to this one
case t of
      (x, y, v) -> 
          case v of 
              ctx @> Just z -> ctx z
(a, ctx @> Just z) -> ctx z

Best regards,
Tomasz