[GHC] #14386: GHC doesn't allow Coercion between partly-saturated type constructors
GHC
ghc-devs at haskell.org
Tue Oct 31 14:59:20 UTC 2017
#14386: GHC doesn't allow Coercion between partly-saturated type constructors
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Reporter: Iceland_jack | Owner: (none)
Type: bug | Status: new
Priority: normal | Milestone:
Component: Compiler | Version: 8.3
Resolution: | Keywords: roles
Operating System: Unknown/Multiple | Architecture:
| Unknown/Multiple
Type of failure: None/Unknown | Test Case:
Blocked By: | Blocking:
Related Tickets: #14317 | Differential Rev(s):
Wiki Page: |
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Changes (by RyanGlScott):
* related: => #14317
Comment:
I think ultimately this ties back to GHC's inability to eta-reduce the
unwrapping rule:
{{{#!hs
Coercible (Op cat a b) (cat b a)
}}}
In other words, it's the same symptom as in
https://ghc.haskell.org/trac/ghc/ticket/14317#comment:6.
--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14386#comment:7>
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