[GHC] #11243: Flag to not expand type families (was: Use Type Synonyms to Compress Errors)

[GHC]

#11243: Flag to not expand type families
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        Reporter:  crockeea          |                Owner:
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:  8.2.1
       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:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by crockeea):

 Please! That would (likely) solve the issue reported in this ticket.

 I can't find a ticket where the solution was to expand type families,
 perhaps someone else recalls the reason for that choice? I wonder if a
 more granular approach might be warranted. Perhaps we could say `-fno-
 print-expanded-type-families -fprint-tf NextListElt` to *only* expand
 `NextListElt`? I don't have a concrete use case for this off the top of my
 head, but if some people want TFs to be expanded, it seems like there
 should be some sort of intermediate solution.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11243#comment:9>
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