1. 18 Nov, 2015 1 commit
    • msosn's avatar
      Fix inconsistent pretty-printing of type families · c61759d5
      msosn authored
      After the changes, the three functions used to print type families
      were identical, so they are refactored into one.
      Original RHSs of data instance declarations are recreated and
      printed in user error messages.
      RHSs containing representation TyCons are printed in the
      Coercion Axioms section in a typechecker dump.
      Add vbar to the list of SDocs exported by Outputable.
      Replace all text "|" docs with it.
      Fixes #10839
      Reviewers: goldfire, jstolarek, austin, bgamari
      Reviewed By: jstolarek
      Subscribers: jstolarek, thomie
      Differential Revision: https://phabricator.haskell.org/D1441
      GHC Trac Issues: #10839
  2. 21 Sep, 2015 1 commit
    • eir@cis.upenn.edu's avatar
      Perform a validity check on assoc type defaults. · e27b267f
      eir@cis.upenn.edu authored
      This fixes #10817 and #10899. A knock-on effect is that we must
      now remember locations of associated type defaults for error
      messages during validity checking. This isn't too bad, but it
      increases the size of the diff somewhat.
      Test cases: indexed-types/should_fail/T108{17,99}
  3. 20 Feb, 2015 1 commit
  4. 19 Jan, 2015 1 commit
    • Alan Zimmerman's avatar
      API Annotations documentation update, parsing issue, add example test · 851ed721
      Alan Zimmerman authored
      Add a reference note to each AnnKeywordId haddock comment so GHC
      developers will have an idea why they are there.
      Add a new test to ghc-api/annotations to serve as a template for other
      GHC developers when they need to update the parser. It provides output
      which checks that each SrcSpan that an annotation is attached to
      actually appears in the `ParsedSource`, and lists the individual
      annotations. The idea is that a developer writes a version of this
      which parses a sample file using whatever syntax is changed in
      Parser.y, and can then check that all the annotations come through.
      Depends on D538
      Test Plan: ./validate
      Reviewers: simonpj, hvr, austin
      Reviewed By: austin
      Subscribers: thomie, jstolarek
      Differential Revision: https://phabricator.haskell.org/D620
  5. 16 Jan, 2015 1 commit
    • Alan Zimmerman's avatar
      API Annotations tweaks. · 11881ec6
      Alan Zimmerman authored
      HsTyLit now has SourceText
      Update documentation of HsSyn to reflect which annotations are attached to which element.
      Ensure that the parser always keeps HsSCC and HsTickPragma values, to
      be ignored in the desugar phase if not needed
      Bringing in SourceText for pragmas
      Add Location in NPlusKPat
      Add Location in FunDep
      Make RecCon payload Located
      Explicitly add AnnVal to RdrName where it is compound
      Add Location in IPBind
      Add Location to name in IEThingAbs
      Add Maybe (Located id,Bool) to Match to track fun_id,infix
        This includes converting Match into a record and adding a note about why
        the fun_id needs to be replicated in the Match.
      Add Location in KindedTyVar
      Sort out semi-colons for parsing
        - import statements
        - stmts
        - decls
        - decls_cls
        - decls_inst
      This updates the haddock submodule.
      Test Plan: ./validate
      Reviewers: hvr, austin, goldfire, simonpj
      Reviewed By: simonpj
      Subscribers: thomie, carter
      Differential Revision: https://phabricator.haskell.org/D538
  6. 01 Dec, 2014 1 commit
  7. 26 Sep, 2014 1 commit
  8. 15 Jul, 2014 1 commit
    • Simon Peyton Jones's avatar
      Entirely re-jig the handling of default type-family instances (fixes Trac #9063) · 9b8ba629
      Simon Peyton Jones authored
      In looking at Trac #9063 I decided to re-design the default
      instances for associated type synonyms.  Previously it was all
      jolly complicated, to support generality that no one wanted, and
      was arguably undesirable.
      * The default instance for an associated type can have only
        type variables on the LHS.  (Not type patterns.)
      * There can be at most one default instances declaration for
        each associated type.
      To achieve this I had to do a surprisingly large amount of refactoring
      of HsSyn, specifically to parameterise HsDecls.TyFamEqn over the type
      of the LHS patterns.
      That change in HsDecls has a (trivial) knock-on effect in Haddock, so
      this commit does a submodule update too.
      The net result is good though.  The code is simpler; the language
      specification is simpler.  Happy days.
      Trac #9263 and #9264 are thereby fixed as well.
  9. 15 May, 2014 1 commit
    • Herbert Valerio Riedel's avatar
      Add LANGUAGE pragmas to compiler/ source files · 23892440
      Herbert Valerio Riedel authored
      In some cases, the layout of the LANGUAGE/OPTIONS_GHC lines has been
      reorganized, while following the convention, to
      - place `{-# LANGUAGE #-}` pragmas at the top of the source file, before
        any `{-# OPTIONS_GHC #-}`-lines.
      - Moreover, if the list of language extensions fit into a single
        `{-# LANGUAGE ... -#}`-line (shorter than 80 characters), keep it on one
        line. Otherwise split into `{-# LANGUAGE ... -#}`-lines for each
        individual language extension. In both cases, try to keep the
        enumeration alphabetically ordered.
        (The latter layout is preferable as it's more diff-friendly)
      While at it, this also replaces obsolete `{-# OPTIONS ... #-}` pragma
      occurences by `{-# OPTIONS_GHC ... #-}` pragmas.
  10. 13 Nov, 2013 1 commit
  11. 01 Oct, 2013 1 commit
  12. 18 Sep, 2013 1 commit
  13. 02 Aug, 2013 1 commit
  14. 28 Jan, 2013 1 commit
    • Simon Peyton Jones's avatar
      More refactoring of FamInst/FamInstEnv; finally fixes Trac #7524 · a98e51ec
      Simon Peyton Jones authored
      Quite a bit of tidying up here; the fix to #7524 is actually
      only a small part.
      * Be fully clear that the cab_tvs in a CoAxBranch are not
        fresh.  See Note [CoAxBranch type variables] in CoAxiom.
      * Use CoAxBranch to replace the ATDfeault type in Class.
        CoAxBranch is perfect here.  This change allowed me to
        delete quite a bit of boilerplate code, including the
        corresponding IfaceSynType.
      * Tidy up the construction of CoAxBranches, and when FamIntBranch is
        freshened.  The latter onw happens only in FamInst.newFamInst.
      * Tidy the tyvars of a CoAxBranch when we build them, done in
        FamInst.mkCoAxBranch.  See Note [Tidy axioms when we build them]
        in that module.  This is what fixes #7524.
      Much niceer now.
  15. 22 Dec, 2012 1 commit
    • eir@cis.upenn.edu's avatar
      Implement overlapping type family instances. · 8366792e
      eir@cis.upenn.edu authored
      An ordered, overlapping type family instance is introduced by 'type
      where', followed by equations. See the new section in the user manual
      ( for details. The canonical example is Boolean equality at the
      type family Equals (a :: k) (b :: k) :: Bool
      type instance where
        Equals a a = True
        Equals a b = False
      A branched family instance, such as this one, checks its equations in
      and applies only the first the matches. As explained in the note
      checking within groups] in FamInstEnv.lhs, we must be careful not to
      say, (Equals Int b) to False, because b might later unify with Int.
      This commit includes all of the commits on the overlapping-tyfams
      branch. SPJ
      requested that I combine all my commits over the past several months
      into one
      monolithic commit. The following GHC repos are affected: ghc, testsuite,
      utils/haddock, libraries/template-haskell, and libraries/dph.
      Here are some details for the interested:
      - The definition of CoAxiom has been moved from TyCon.lhs to a
        new file CoAxiom.lhs. I made this decision because of the
        number of definitions necessary to support BranchList.
      - BranchList is a GADT whose type tracks whether it is a
        singleton list or not-necessarily-a-singleton-list. The reason
        I introduced this type is to increase static checking of places
        where GHC code assumes that a FamInst or CoAxiom is indeed a
        singleton. This assumption takes place roughly 10 times
        throughout the code. I was worried that a future change to GHC
        would invalidate the assumption, and GHC might subtly fail to
        do the right thing. By explicitly labeling CoAxioms and
        FamInsts as being Unbranched (singleton) or
        Branched (not-necessarily-singleton), we make this assumption
        explicit and checkable. Furthermore, to enforce the accuracy of
        this label, the list of branches of a CoAxiom or FamInst is
        stored using a BranchList, whose constructors constrain its
        type index appropriately.
      I think that the decision to use BranchList is probably the most
      controversial decision I made from a code design point of view.
      Although I provide conversions to/from ordinary lists, it is more
      efficient to use the brList... functions provided in CoAxiom than
      always to convert. The use of these functions does not wander far
      from the core CoAxiom/FamInst logic.
      BranchLists are motivated and explained in the note [Branched axioms] in
      - The CoAxiom type has changed significantly. You can see the new
        type in CoAxiom.lhs. It uses a CoAxBranch type to track
        branches of the CoAxiom. Correspondingly various functions
        producing and consuming CoAxioms had to change, including the
        binary layout of interface files.
      - To get branched axioms to work correctly, it is important to have a
        of type "apartness": two types are apart if they cannot unify, and no
        substitution of variables can ever get them to unify, even after type
        simplification. (This is different than the normal failure to unify
        of the type family bit.) This notion in encoded in tcApartTys, in
        Because apartness is finer-grained than unification, the tcUnifyTys
        calls tcApartTys.
      - CoreLinting axioms has been updated, both to reflect the new
        form of CoAxiom and to enforce the apartness rules of branch
        application. The formalization of the new rules is in
      - The FamInst type (in types/FamInstEnv.lhs) has changed
        significantly, paralleling the changes to CoAxiom. Of course,
        this forced minor changes in many files.
      - There are several new Notes in FamInstEnv.lhs, including one
        discussing confluent overlap and why we're not doing it.
      - lookupFamInstEnv, lookupFamInstEnvConflicts, and
        lookup_fam_inst_env' (the function that actually does the work)
        have all been more-or-less completely rewritten. There is a
        Note [lookup_fam_inst_env' implementation] describing the
        implementation. One of the changes that affects other files is
        to change the type of matches from a pair of (FamInst, [Type])
        to a new datatype (which now includes the index of the matching
        branch). This seemed a better design.
      - The TySynInstD constructor in Template Haskell was updated to
        use the new datatype TySynEqn. I also bumped the TH version
        number, requiring changes to DPH cabal files. (That's why the
        DPH repo has an overlapping-tyfams branch.)
      - As SPJ requested, I refactored some of the code in HsDecls:
       * splitting up TyDecl into SynDecl and DataDecl, correspondingly
         changing HsTyDefn to HsDataDefn (with only one constructor)
       * splitting FamInstD into TyFamInstD and DataFamInstD and
         splitting FamInstDecl into DataFamInstDecl and TyFamInstDecl
       * making the ClsInstD take a ClsInstDecl, for parallelism with
         InstDecl's other constructors
       * changing constructor TyFamily into FamDecl
       * creating a FamilyDecl type that stores the details for a family
         declaration; this is useful because FamilyDecls can appear in classes
         other decls cannot
       * restricting the associated types and associated type defaults for a
       * class
         to be the new, more restrictive types
       * splitting cid_fam_insts into cid_tyfam_insts and cid_datafam_insts,
         according to the new types
       * perhaps one or two more that I'm overlooking
      None of these changes has far-reaching implications.
      - The user manual, section, is updated to describe the new type
  16. 14 Jul, 2012 1 commit
  17. 12 Jun, 2012 1 commit
  18. 23 Dec, 2011 1 commit
  19. 11 Nov, 2011 1 commit
    • dreixel's avatar
      New kind-polymorphic core · 09015be8
      dreixel authored
      This big patch implements a kind-polymorphic core for GHC. The current
      implementation focuses on making sure that all kind-monomorphic programs still
      work in the new core; it is not yet guaranteed that kind-polymorphic programs
      (using the new -XPolyKinds flag) will work.
      For more information, see http://haskell.org/haskellwiki/GHC/Kinds
  20. 04 Nov, 2011 2 commits
  21. 09 Sep, 2011 1 commit
    • batterseapower's avatar
      Implement associated type defaults · de8c8d68
      batterseapower authored
      Basically, now you can write:
        class Cls a where
          type Typ a
          type Typ a = Just a
      And now if an instance does not specify an explicit associated type
      instance, one will be generated afresh based on that default. So for
      example this instance:
        instance Cls Int where
      Will be equivalent to this one:
        instance Cls Int where
          type Typ Int = Just Int
  22. 07 Sep, 2011 1 commit
  23. 06 Sep, 2011 1 commit
    • batterseapower's avatar
      Implement -XConstraintKind · 9729fe7c
      batterseapower authored
      Basically as documented in http://hackage.haskell.org/trac/ghc/wiki/KindFact,
      this patch adds a new kind Constraint such that:
        Show :: * -> Constraint
        (?x::Int) :: Constraint
        (Int ~ a) :: Constraint
      And you can write *any* type with kind Constraint to the left of (=>):
      even if that type is a type synonym, type variable, indexed type or so on.
      The following (somewhat related) changes are also made:
       1. We now box equality evidence. This is required because we want
          to give (Int ~ a) the *lifted* kind Constraint
       2. For similar reasons, implicit parameters can now only be of
          a lifted kind. (?x::Int#) => ty is now ruled out
       3. Implicit parameter constraints are now allowed in superclasses
          and instance contexts (this just falls out as OK with the new
          constraint solver)
      Internally the following major changes were made:
       1. There is now no PredTy in the Type data type. Instead
          GHC checks the kind of a type to figure out if it is a predicate
       2. There is now no AClass TyThing: we represent classes as TyThings
          just as a ATyCon (classes had TyCons anyway)
       3. What used to be (~) is now pretty-printed as (~#). The box
          constructor EqBox :: (a ~# b) -> (a ~ b)
       4. The type LCoercion is used internally in the constraint solver
          and type checker to represent coercions with free variables
          of type (a ~ b) rather than (a ~# b)
  24. 12 Jul, 2011 1 commit
  25. 22 Jun, 2011 1 commit
    • Simon Peyton Jones's avatar
      Add equality superclasses · 940d1309
      Simon Peyton Jones authored
      Hurrah.  At last we can write
         class (F a ~ b) => C a b where { ... }
      This fruit of the fact that equalities are now values,
      and all evidence is handled uniformly.
      The main tricky point is that when translating to Core
      an evidence variable 'v' is represented either as
        either   Var v
        or       Coercion (CoVar v)
      depending on whether or not v is an equality.  This leads
      to a few annoying calls to 'varToCoreExpr'.
  26. 12 Apr, 2011 1 commit
  27. 13 Sep, 2010 1 commit
  28. 30 Aug, 2010 2 commits
  29. 07 Jul, 2010 1 commit
    • simonpj@microsoft.com's avatar
      Fix Trac #4127 (and hence #4173) · f87cc9cf
      simonpj@microsoft.com authored
      The change involves a little refactoring, so that the default
      method Ids are brought into scope earlier, before the value
      declarations are compiled.  (Since a value decl may contain
      an instance decl in a quote.)
      See Note [Default method Ids and Template Haskell] in
  30. 25 May, 2010 1 commit
    • simonpj@microsoft.com's avatar
      Refactor (again) the handling of default methods · 78693246
      simonpj@microsoft.com authored
      This patch fixes Trac #4056, by 
       a) tidying up the treatment of default method names
       b) removing the 'module' argument to newTopSrcBinder
      The details aren't that interesting, but the result
      is much tidier. The original bug was a 'nameModule' panic,
      caused by trying to find the module of a top-level name.
      But TH quotes generate Internal top-level names that don't
      have a module, and that is generally a good thing.  
      Fixing that in turn led to the default-method refactoring,
      which also makes the Name for a default method be handled
      in the same way as other derived names, generated in BuildTyCl
      via a call newImplicitBinder.  Hurrah.
  31. 30 Mar, 2010 1 commit
  32. 01 Dec, 2008 1 commit
  33. 12 Apr, 2008 1 commit
  34. 29 Mar, 2008 1 commit
  35. 25 Jan, 2008 1 commit
  36. 04 Sep, 2007 1 commit
  37. 03 Sep, 2007 1 commit
  38. 01 Sep, 2007 1 commit