Hi GHC users,
Now that the Glorious New type checker can handle local evidence
seamlessly, is it a big implementation burden to extend it to deal
with local *type class instances* in addition to local *equality
constraints*?
For example, you could write this:
f :: Bool
f = id id
where
Forwarding to list.
-- Forwarded message --
From: Antoine Latter aslat...@gmail.com
Date: Sat, Oct 16, 2010 at 9:47 AM
Subject: Re: Local evidence and type class instances
To: Max Bolingbroke batterseapo...@hotmail.com
On Sat, Oct 16, 2010 at 7:11 AM, Max Bolingbroke
On Sat, Oct 16, 2010 at 7:11 AM, Max Bolingbroke
batterseapo...@hotmail.com wrote:
Hi GHC users,
Now that the Glorious New type checker can handle local evidence
seamlessly, is it a big implementation burden to extend it to deal
with local *type class instances* in addition to local *equality
HI Antoine,
I didn't know UHC already had this - thanks for the pointer! It seems
they have read about implicit configurations too, as the example they
use is very similar to the paper.
In fact, they also have another extension to the concept that I was
intentionally avoiding mentioning - they
On Sat, Oct 16, 2010 at 11:41 AM, Max Bolingbroke
batterseapo...@hotmail.com wrote:
On 16 October 2010 15:47, Antoine Latter aslat...@gmail.com wrote:
Substituting f for f' in this example will change the meaning of the
operation significantly, which is, in my mind, hard to explain and
reason
Hi Simon,
I've seen this issue with GHC 6.12.3 (and assumed it was by design).
It occurs with a slight modification of your example:
{-# LANGUAGE RecordWildCards #-}
module Test where
data T = MkT { f,g :: Int }
p x = let MkT{..} = x in f
This example warns about Defined but not used: `g' on
