| Excellent, I added responses ("thomasw") to your comments on the wiki | page. OK, good. Better still, improve your wording so that no one could make the same mistake as I did, and delete both comments. Simon | -----Original Message----- | From: Thomas Winant [mailto:thomas.winant@cs.kuleuven.be] | Sent: 13 March 2014 19:38 | To: Simon Peyton Jones; ghc-devs@haskell.org | Cc: Tom Schrijvers; Frank Piessens | Subject: Re: Proposal: Partial Type Signatures | | On 13-03-14 10:46, Simon Peyton Jones wrote: | > | Together with Tom Schrijvers, Frank Piessens and Dominique Devriese, | > | I have been working on a proposal for adding *Partial Type | > | Signatures* to GHC. | > | > I'm all for this. Yes, if the design and implementation are solid, | I'd be happy to add it to the main branch. | > | > Do focus on something with excellent power-to-weight ratio: that is, | gives a lot of benefit for a small cost, rather than something that | gives 10% more benefit for 200% more cost. | > | > I've annotated the wiki page with some "SLPJ" comments, which you may | want to look at. | > | > I'd be happy to have a Skype conversation about the details in due | course. | | Excellent, I added responses ("thomasw") to your comments on the wiki | page. | | Cheers, | Thomas | | | > | -----Original Message----- | > | From: ghc-devs [mailto:ghc-devs-bounces@haskell.org] On Behalf Of | > | Thomas Winant | > | Sent: 12 March 2014 13:36 | > | To: ghc-devs@haskell.org | > | Cc: Tom Schrijvers; Frank Piessens | > | Subject: Proposal: Partial Type Signatures | > | | > | Dear GHC developers, | > | | > | Together with Tom Schrijvers, Frank Piessens and Dominique Devriese, | > | I have been working on a proposal for adding *Partial Type | > | Signatures* to GHC. In a partial type signature, annotated types can | > | be mixed with inferred types. A type signature is written like | > | before, but can now contain wildcards, written as underscores. The | > | types of these wildcards or unknown types will be inferred by the | type checker, e.g. | > | | > | foo :: _ -> Bool | > | foo x = not x | > | -- Inferred: Bool -> Boo | > | | > | The proposal also includes a form of generalisation which aligns | > | with the existing generalisation that GHC does. We have written down | > | a motivation (when and how might you use this) and details about the | > | design and implementation on the following wiki page: | > | | > | https://ghc.haskell.org/trac/ghc/wiki/PartialTypeSignatures | > | | > | We have a (work in progress) implementation [1] of the feature based | > | on GHC. It currently implements most of what we propose, but there | > | are some remaining important bugs mostly concerning the | > | generalisation. We also described our design and presented a | > | formalisation based on the | > | OutsideIn(X) formalism in a paper [2] presented at PADL'14. | > | | > | What we are hoping to get from the people on this list is any of the | > | below: | > | * Read the design, play with the implementation and tell us any | comments | > | you may have about the feature, its design and implementation. | > | * Opinions on whether this feature might be acceptable in GHC | upstream | > | at some point (if not, we do not think it's worth developing the | > | implementation much further). | > | * Perhaps a code review or a discussion with someone more | knowledgeable | > | about the internals of GHC's type checker about how we might fix | the | > | remaining problems in our implementation (specifically, we could | use | > | some help with implementing the generalisation of partial type | > | signatures). | > | * Feedback on the `Questions and issues' section on the wiki page. | > | | > | | > | Kind regards, | > | Thomas Winant | > | | > | [1]: https://github.com/mrBliss/ghc-head/ | > | [2]: | > | https://lirias.kuleuven.be/bitstream/123456789/423475/3/paper.pdf | > | | > | | > | Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm | > | _______________________________________________ | > | ghc-devs mailing list | > | ghc-devs@haskell.org | > | http://www.haskell.org/mailman/listinfo/ghc-devs | > | | Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm