Re: Proposal: Add IsString and Monoid instances for Doc

Did you test how many packages this would break, i.e., how many packages define their own instance for Monoid Doc? On 24 October 2010 09:16, Bas van Dijk wrote:

On Fri, Oct 8, 2010 at 9:52 AM, Bas van Dijk wrote:

...

Hello,

Since we're discussing a proposal for the pretty package I would like to make another one:

The proposal is to add the following to Text.PrettyPrint.HughesPJ:

instance IsString Doc where    fromString = text

This allows users to use string literals as Doc values using the OverloadedStrings language extension.

I would also like to add:

instance Monoid Doc where    mempty  = empty    mappend = (<>)

If there's enough demand (because it's a lot of work) I can find out if this change breaks anything by analyzing pretty's direct reverse dependencies:

http://bifunctor.homelinux.net/~roel/cgi-bin/hackage-scripts/revdeps/pretty-...

to see if some of them define an orphaned instance for IsString or Monoid.

The patch that implements this is attached to the ticket:

http://hackage.haskell.org/trac/ghc/ticket/4378

Deadline: 2 weeks (Friday 22 October 2010)

Regards,

Bas

The deadline for this proposal has passed. There were no objections.

I will move the ticket status to 'patch'.

Thanks,

Bas _______________________________________________ Libraries mailing list Libraries@haskell.org http://www.haskell.org/mailman/listinfo/libraries

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