Call to arms: lambda-case is stuck and needs your help

[Mikhail Vorozhtsov]

On 07/06/2012 05:47 AM, Donn Cave wrote:
> The `multi-clause lambda' seems more elegant, if the syntactical
> problems could be worked out.  I mean, unnamed functions are thus
> just like named functions, something that you'd probably think to
> try just as soon as you needed the feature.
>
> I don't understand the issues well enough with the layout rules to
> comment on Tyson Whitehead's ideas about that, and for the same
> reason this may be a useless idea, but what if each clause were
> introduced by \, would that clarify the column structure, or does
> indented block structure require a less-indented `layout herald'?
>
>    f = \ (Just a) (Just b) | a < 0 || b < 0 -> Nothing
>        \ (Just a) (Just b) -> Just (a * b)
>        \ _ _ -> Nothing
>
> 	Donn
This was suggested in the ticket comments, see 
http://hackage.haskell.org/trac/ghc/ticket/4359#comment:29
I'll add it to the list.