[Haskell-cafe] Re: Lambda-case / lambda-if

Max Bolingbroke batterseapower at hotmail.com
Sat Oct 2 19:59:22 EDT 2010


Thanks to everyone who replied - it looks like this feature is enough
in demand that GHC HQ may want to accept it. I've created a ticket at
http://hackage.haskell.org/trac/ghc/ticket/4359

On 2 October 2010 14:23, Max Bolingbroke <batterseapower at hotmail.com> wrote:
> 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: http://www.haskell.org/ghc/  :? 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
> "Cafe"
> Prelude> (case of 1 -> "One"; _ -> "Not-one") 1
> "One"
> 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.
>
> Max
>
> [1] http://hackage.haskell.org/trac/haskell-prime/ticket/41
> [2] http://www.omega-prime.co.uk/files/LambdaCase-Testsuite.patch
> [3] http://www.omega-prime.co.uk/files/LambdaCase-Compiler.patch
>


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