Max Bolingbroke | 2 Oct 20:23 2010

Lambda-case / lambda-if

Hi Cafe,

I implemented the proposed Haskell' feature lambda-case/lambda-if [1]
during the Haskell Implementors Workshop yesterday for a bit of fun.
The patches are online [2, 3].

The feature is demonstrated in this GHCi session:

$ inplace/bin/ghc-stage2 --interactive -XLambdaCase
GHCi, version 7.1.20101002:  :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... done.
Loading package ffi-1.0 ... linking ... done.
Prelude> (if then "Haskell" else "Cafe") False
Prelude> (case of 1 -> "One"; _ -> "Not-one") 1
Prelude> :q

Do you like this feature and think it would be worth incorporating
this into GHC? Or is it too specialised to be of use? If there is
enough support, I'll create a ticket and see what GHC HQ make of it.