[GHC] #11049: Allow CallStacks to be hidden or cut

[GHC]

#11049: Allow CallStacks to be hidden or cut
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        Reporter:  nomeata           |                Owner:  gridaphobe
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  7.10.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #11035            |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by simonpj):

 That's helpful.  So we make public both `rootStack` and `pushCallStack`.
 And we allow implicit-parameter bindings for `?loc :: CallStack`.   (I
 suppose that's always been possible, and you can use it already to install
 a `CallStack` from somewhere else.  I guess that's an advantage.)

 Would you like to turn the description, and  your comment:3, and any
 subsequent stuff, into a wiki page (perhaps the same page as the current
 `CallStack` one.  Otherwise we have to mentally compose all these things
 in our heads.  Thanks!

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11049#comment:5>
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