Concrete syntax for pattern synonym type signatures
Simon Peyton Jones
simonpj at microsoft.com
Mon Nov 10 21:07:55 UTC 2014
Well done! Thanks Gergo.
| -----Original Message-----
| From: Dr. ERDI Gergo [mailto:gergo at erdi.hu]
| Sent: 10 November 2014 14:09
| To: Simon Peyton Jones
| Cc: Richard Eisenberg; GHC Devs
| Subject: RE: Concrete syntax for pattern synonym type signatures
|
| Good news, I've made the necessary parser breakthrough and I've now got
|
| pattern P :: pretty much anything after this point
|
| to parse as a pattern synonym type signature on a local sub-branch of my
| branch. So no more annoying 'pattern type' nonsense.
|
| As for the 'pretty much anything' part, I have SPJ's original proposal
| implemented as a proof-of-concept:
|
| pattern C :: forall b c. (; Eq b, Num b) => b -> c -> X Maybe (Maybe
| b)
|
| But I see that the popular opinion now seems to be moving to
|
| pattern C :: () => (Eq b, Num b) => b -> c -> X Maybe (Maybe b)
|
| which should be even easier to implement now, so I hope to finish the
| branch in a couple days (it probably doesn't need more than an evening's
| work now).
|
| Thanks go out to everyone who contributed in this little syntax
| bikeshedding exercise.
|
| Bye,
| Gergo
|
|
| --
|
| .--= ULLA! =-----------------.
| \ http://gergo.erdi.hu \
| `---= gergo at erdi.hu =-------'
| Define (n.) De ting you get for breaking de law.
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