[GHC] #13795: :kind! is not expanding type synonyms anymore
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Fri Jun 9 07:56:51 UTC 2017
#13795: :kind! is not expanding type synonyms anymore
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Reporter: Hjulle | Owner: (none)
Type: bug | Status: new
Priority: normal | Milestone:
Component: GHCi | Version: 8.0.2
Resolution: | Keywords: newcomer
Operating System: Unknown/Multiple | Architecture:
| Unknown/Multiple
Type of failure: None/Unknown | Test Case:
Blocked By: | Blocking:
Related Tickets: | Differential Rev(s):
Wiki Page: |
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Comment (by simonpj):
We could offer some way to get
* No processing of the type (currently `:kind`)
* Type families evaluated (currently `:kind!`)
* Type families evaluated and type synonyms expanded (`:kind!!` perhaps?)
And, I suppose, the fourth possibility (expand type synonyms but do not
evaluate type families).
But that's probably over-complicated -- few users would care.
If we are going to have only two possibilities (`:k` and `:k!`), what the
user manual says makes most sense: `:kind!` evaluates everything, type
families, type synonyms and all.
I suppose we could have a `:set -XNoExpandSynonymsOnBang` flag or
something.
Implementation is easy. The hard thing to know is what users want.
Users, speak up!
--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13795#comment:6>
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