[Haskell-cafe] GHC 7.4 and TypeSynonymInstances

[Ivan Lazar Miljenovic]

On 7 June 2012 16:26, Simon Peyton-Jones <simonpj at microsoft.com> wrote:
> It's deliberate.
>
> As the user manual says (http://www.haskell.org/ghc/docs/latest/html/users_guide/flag-reference.html#id3101511), FlexibleInstances implies TypeSynonymInstances.
> See Trac http://hackage.haskell.org/trac/ghc/ticket/4841
>
> I'll clarify the docs a bit.

That makes more sense now, thanks!

>
> Simon
>
> | -----Original Message-----
> | From: haskell-cafe-bounces at haskell.org [mailto:haskell-cafe-
> | bounces at haskell.org] On Behalf Of Ivan Lazar Miljenovic
> | Sent: 06 June 2012 23:34
> | To: Haskell Cafe
> | Subject: Re: [Haskell-cafe] GHC 7.4 and TypeSynonymInstances
> |
> | *Bump*
> |
> | Especially as there is now a version of the Haskell Platform based
> | around GHC-7.4.1, I would appreciate it if this behaviour could be
> | clarified.
> |
> | On 20 April 2012 15:25, Ivan Lazar Miljenovic
> | <ivan.miljenovic at gmail.com> wrote:
> | > Has there been a change in the behaviour/requirement of
> | > TypeSynonymInstances as of GHC-7.4.1? (Not sure if this behaviour
> | > occurs with 7.2.1 as I don't have it installed)
> | >
> | > I had an instance for String for a class which ghc accepted whilst
> | > using FlexibleInstances; however, when trying to load it in 7.0.* it
> | > stated that TypeSynonymInstances was needed (which I forgot to add
> | > since it didn't seem to need it).
> | >
> | > All I could find in the release notes was that as of 7.2.1, both
> | > extensions were needed, not that one implied the other:
> | > http://www.haskell.org/ghc/docs/7.4.1/html/users_guide/release-7-2-1.h
> | > tml#id3003826
> | >
> | > Is this behaviour deliberate, or a bug?
> | >
> | > --
> | > Ivan Lazar Miljenovic
> | > Ivan.Miljenovic at gmail.com
> | > http://IvanMiljenovic.wordpress.com
> |
> |
> |
> | --
> | Ivan Lazar Miljenovic
> | Ivan.Miljenovic at gmail.com
> | http://IvanMiljenovic.wordpress.com
> |
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>



-- 
Ivan Lazar Miljenovic
Ivan.Miljenovic at gmail.com
http://IvanMiljenovic.wordpress.com