[GHC] #8215: Out of scope with `-dcore-lint` and derived instances in GHCi

[GHC]

#8215: Out of scope with `-dcore-lint` and derived instances in GHCi
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        Reporter:  nomeata           |            Owner:
            Type:  bug               |           Status:  new
        Priority:  normal            |        Milestone:
       Component:  Compiler          |          Version:  7.6.3
      Resolution:                    |         Keywords:
Operating System:  Unknown/Multiple  |     Architecture:  Unknown/Multiple
 Type of failure:  None/Unknown      |       Difficulty:  Unknown
       Test Case:                    |       Blocked By:
        Blocking:                    |  Related Tickets:
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Comment (by Simon Peyton Jones <simonpj@…>):

 In [changeset:dfa8ef031c83998c163bb94fb84ff8e02ef86cf8/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="dfa8ef031c83998c163bb94fb84ff8e02ef86cf8"
 Improve Linting in GHCi (fixes Trac #8215)

 The original problem was that we weren't bringing varaibles bound in the
 interactive context into scope before Linting the result of a top-level
 declaration in GHCi.  (We were doing this for expressions.)

 Moreover I found that we weren't Linting the result of desugaring
 a GHCi expression, which we really should be doing.

 It took me a bit of time to unravel all this, and I did some refactoring
 to make it easier next time.

   * CoreMonad contains the Lint wrappers that get the right
     environments into place.  It always had endPass and lintPassResult
     (which Lints bindings), but now it has lintInteractiveExpr.

   * Both use a common function CoreMonad.interactiveInScope to find
     those in-scope variables.

 Quite a bit of knock-on effects from this, but nothing exciting.
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8215#comment:3>
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