[GHC] #3306: Improve syntax for GADT + records

[GHC]

#3306: Improve syntax for GADT + records
---------------------------------+------------------------------------------
    Reporter:  simonpj           |        Owner:  simonpj         
        Type:  feature request   |       Status:  closed          
    Priority:  normal            |    Milestone:  6.12.1          
   Component:  Compiler          |      Version:  6.10.2          
    Severity:  normal            |   Resolution:  fixed           
    Keywords:                    |   Difficulty:  Unknown         
    Testcase:                    |           Os:  Unknown/Multiple
Architecture:  Unknown/Multiple  |  
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Changes (by simonpj):

  * status:  new => closed
  * resolution:  => fixed

Comment:

 In fact I'd even committed that patch, so I declare this done:
 {{{
 Thu Jul  2 10:46:57 BST 2009  simonpj at microsoft.com
   * New syntax for GADT-style record declarations, and associated
 refactoring

   The main purpose of this patch is to fix Trac #3306, by fleshing out the
   syntax for GADT-style record declraations so that you have a context in
   the type.  The new form is
      data T a where
        MkT :: forall a. Eq a => { x,y :: !a } -> T a
   See discussion on the Trac ticket.

   The old form is still allowed, but give a deprecation warning.

   When we remove the old form we'll also get rid of the one reduce/reduce
   error in the grammar. Hurrah!

   While I was at it, I failed as usual to resist the temptation to do lots
 of
   refactoring.  The parsing of data/type declarations is now much simpler
 and
   more uniform.  Less code, less chance of errors, and more functionality.
   Took longer than I planned, though.

   ConDecl has record syntax, but it was not being used consistently, so I
   pushed that through the compiler.


     M ./compiler/deSugar/DsMeta.hs -4 +4
     M ./compiler/hsSyn/Convert.lhs -20 +29
     M ./compiler/hsSyn/HsDecls.lhs -23 +26
     M ./compiler/hsSyn/HsTypes.lhs -2 +21
     M ./compiler/parser/HaddockUtils.hs -6 +5
     M ./compiler/parser/Parser.y.pp -143 +64
     M ./compiler/parser/ParserCore.y -21 +14
     M ./compiler/parser/RdrHsSyn.lhs -188 +205
     M ./compiler/rename/RnHsSyn.lhs +1
     M ./compiler/rename/RnSource.lhs -65 +56
     M ./compiler/rename/RnTypes.lhs -5 +19
     M ./compiler/typecheck/TcHsType.lhs -4 +12
     M ./compiler/typecheck/TcTyClsDecls.lhs -3 +6
     M ./docs/users_guide/glasgow_exts.xml -19 +60
 }}}
 Simon

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/3306#comment:7>
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