[Haskell-cafe] Call for discussion: OverloadedLists extension

[Mario Blažević]

On 12-09-26 08:07 PM, wren ng thornton wrote:
> On 9/25/12 1:57 PM, Sjoerd Visscher wrote:
>>> Maybe we could make a literal [a,b,c] turn into
>>>     unpack [a,b,c]#
>>> where
>>>     [a,b,c]#
>>> is a statically-allocated vector?
>
> I'm kinda surprised this isn't already being done. Just doing this seems
> like it'd be a good undertaking, regardless of whether we get overloaded
> list literals. Just storing the literal as a C-like array and inflating
> it to a list/array/vector at runtime seems like it should be a big win
> for code that uses a lot of literals.

Why?

	I'm surprised that this is an issue at all. If list literals you are 
talking about are constant, wouldn't GHC apply constant folding and 
construct the list only the first time it's needed?