[Haskell-cafe] Call to arms: lambda-case is stuck and needs your help

[Daniel Trstenjak]

On Thu, Jul 12, 2012 at 03:13:42PM -0400, Cale Gibbard wrote:
> There are of course already lots of ways to create functions which
> don't involve \

Well, I think it should be clear that we're talking here about
anonymous functions.

> We're not exactly talking about function definitions, so much as
> expressions whose value happens to be a function. The point is just
> that there are already a few other places in the syntax where the
> omission of a value results in a function having the omitted value as
> its parameter. At least to me, it seems natural to extend that pattern
> in this case.

The question is, how self explanatory is the syntax? I think that
sections and partial function application are pretty self explanatory
just by looking at the expression, because it tells you visually pretty
well what it actually does.

'case of {}' isn't self explanatory, because you don't have a visual
hint what happend with the parameter between 'case' and 'of'.

I can see why - I think it was Simon - proposed '\of', because you could
read it as if the parameter between 'case' and 'of' is applied to the 'of'.

I don't like the version 'case of {}' and I even don't like the version
'\case of' that much, because I think both versions degrade the syntax
of Haskell, which is part of the beauty of Haskell and we shouldn't rush
in expanding it, only for pragmatic reasons.


Greetings,
Daniel