[GHC] #10330: Better Template Haskell error message locations

[GHC]

#10330: Better Template Haskell error message locations
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        Reporter:  simonpj           |                   Owner:
            Type:  bug               |                  Status:  new
        Priority:  normal            |               Milestone:
       Component:  Template Haskell  |                 Version:  7.10.1
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:
 Type of failure:  None/Unknown      |  Unknown/Multiple
      Blocked By:                    |               Test Case:
 Related Tickets:                    |                Blocking:
                                     |  Differential Revisions:
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Comment (by goldfire):

 In my opinion, (2) above is more important than (1). The `singletons`
 package encourages wrapping up lots of code in one big splice and quote.
 (`$(singletons [d| data Foo = ... ; bar :: ...; bar = ...; ... |])`)
 Because of the bug reported here, users get no location information
 attached to often-baroque errors.

 Agreed that (2) is quite a bit harder to fix than (1), though. (2) would
 seem to require a full overhaul of the TH AST and would break many clients
 of TH.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10330#comment:1>
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