#4894: Missing improvement for fun. deps.
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Reporter: diatchki | Owner:
Type: bug | Status: new
Priority: normal | Milestone:
Component: Compiler (Type checker) | Version: 7.1
Keywords: | Testcase:
Blockedby: | Difficulty:
Os: Unknown/Multiple | Blocking:
Architecture: Unknown/Multiple | Failure: None/Unknown
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Comment(by diatchki):
(Thanks for the link, I've been looking at an older version of the paper).
I had forgotten that FC already had a built-in "axiom" construct. With
this, I think that the only thing that would need to change is to
generalize axioms to allow them to have parameters. This is a
generalization because we can use it to express conditional equalities.
Then, what I was trying to say above amounts to: a class declaration with
FDs
{{{
class C a b | a -> b, b -> a where ...
}}}
translates in FC to:
{{{
data C a b where ...
axiom C_fd0 a b1 b2 : (C a b1, C a b2) => (b1 ~ b2)
axiom C_fd1 a1 a2 b : (C a1 b, C a2 b) => (a1 ~ a2)
}}}
(I wrote the axiom parameters using "(...) =>" to mimic Hashell's
notation)
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/4894#comment:6>
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