1. 24 Jan, 2017 1 commit
    • Ryan Scott's avatar
      Don't put foralls in front of TH-spliced GADT constructors that don't need them · 9fd87ef8
      Ryan Scott authored
      Summary:
      It turns out that D2974 broke this program
      (see https://phabricator.haskell.org/rGHC729a5e452db5#58801):
      
      ```lang=haskell
      {-# LANGUAGE ConstraintKinds #-}
      {-# LANGUAGE GADTs #-}
      {-# LANGUAGE KindSignatures #-}
      {-# LANGUAGE TemplateHaskell #-}
      {-# OPTIONS_GHC -ddump-splices #-}
      module Bug where
      
      import GHC.Exts (Constraint)
      
      $([d| data Dec13 :: (* -> Constraint) -> * where
              MkDec13 :: c a => a -> Dec13 c
          |])
      ```
      
      This was actually due to a long-standing bug in `hsSyn/Convert` that put
      unnecessary `forall`s in front of GADT constructors that didn't have any
      explicitly quantified type variables.
      
      This cargo-cults the code in `Convert` that handles `ForallT` and adapts
      it to `ForallC`. Fixes #13123 (for real this time).
      
      Test Plan: make test TEST=T13123
      
      Reviewers: goldfire, austin, bgamari
      
      Reviewed By: bgamari
      
      Subscribers: thomie
      
      Differential Revision: https://phabricator.haskell.org/D3002
      
      GHC Trac Issues: #13123
      9fd87ef8
  2. 21 Dec, 2016 1 commit
  3. 12 Dec, 2016 1 commit
    • Alan Zimmerman's avatar
      Add infix flag for class and data declarations · 8f6d241a
      Alan Zimmerman authored
      Summary:
      At the moment, data and type declarations using infix formatting produce the
      same AST as those using prefix.
      
      So
      
          type a ++ b = c
      
      and
      
          type (++) a b = c
      
      cannot be distinguished in the parsed source, without looking at the OccName
      details of the constructor being defined.
      
      Having access to the OccName requires an additional constraint which explodes
      out over the entire AST because of its recursive definitions.
      
      In keeping with moving the parsed source to more directly reflect the source
      code as parsed, add a specific flag to the declaration to indicate the fixity,
      as used in a Match now too.
      
      Note: this flag is to capture the fixity used for the lexical definition of the
      type, primarily for use by ppr and ghc-exactprint.
      
      Updates haddock submodule.
      
      Test Plan: ./validate
      
      Reviewers: mpickering, goldfire, bgamari, austin
      
      Reviewed By: mpickering
      
      Subscribers: thomie
      
      Differential Revision: https://phabricator.haskell.org/D2828
      
      GHC Trac Issues: #12942
      8f6d241a
  4. 09 Dec, 2016 1 commit
    • Ryan Scott's avatar
      Rename TH constructors for deriving strategies · 5349d648
      Ryan Scott authored
      After talking to Richard, he and I concluded that choosing the rather
      common name `Newtype` to represent the corresponding deriving strategy
      in Template Haskell was a poor choice of name. I've opted to rename it
      to something less common (`NewtypeStrategy`) while we still have time. I
      also renamed the corrsponding datatype in the GHC internals so as to
      match it.
      
      Reviewers: austin, goldfire, hvr, bgamari
      
      Reviewed By: bgamari
      
      Subscribers: thomie, mpickering
      
      Differential Revision: https://phabricator.haskell.org/D2814
      
      GHC Trac Issues: #10598
      5349d648
  5. 07 Dec, 2016 1 commit
    • Alan Zimmerman's avatar
      Add HsSyn prettyprinter tests · 499e4382
      Alan Zimmerman authored
      Summary:
      Add prettyprinter tests, which take a file, parse it, pretty print it,
      re-parse the pretty printed version and then compare the original and
      new ASTs (ignoring locations)
      
      Updates haddock submodule to match the AST changes.
      
      There are three issues outstanding
      
      1. Extra parens around a context are not reproduced. This will require an
         AST change and will be done in a separate patch.
      
      2. Currently if an `HsTickPragma` is found, this is not pretty-printed,
         to prevent noise in the output.
      
         I am not sure what the desired behaviour in this case is, so have left
         it as before. Test Ppr047 is marked as expected fail for this.
      
      3. Apart from in a context, the ParsedSource AST keeps all the parens from
         the original source.  Something is happening in the renamer to remove the
         parens around visible type application, causing T12530 to fail, as the
         dumped splice decl is after the renamer.
      
         This needs to be fixed by keeping the parens, but I do not know where they
         are being removed.  I have amended the test to pass, by removing the parens
         in the expected output.
      
      Test Plan: ./validate
      
      Reviewers: goldfire, mpickering, simonpj, bgamari, austin
      
      Reviewed By: simonpj, bgamari
      
      Subscribers: simonpj, goldfire, thomie, mpickering
      
      Differential Revision: https://phabricator.haskell.org/D2752
      
      GHC Trac Issues: #3384
      499e4382
  6. 01 Oct, 2016 1 commit
    • Ryan Scott's avatar
      Implement deriving strategies · 9e862765
      Ryan Scott authored
      Allows users to explicitly request which approach to `deriving` to use
      via keywords, e.g.,
      
      ```
      newtype Foo = Foo Bar
        deriving Eq
        deriving stock    Ord
        deriving newtype Show
      ```
      
      Fixes #10598. Updates haddock submodule.
      
      Test Plan: ./validate
      
      Reviewers: hvr, kosmikus, goldfire, alanz, bgamari, simonpj, austin,
      erikd, simonmar
      
      Reviewed By: alanz, bgamari, simonpj
      
      Subscribers: thomie, mpickering, oerjan
      
      Differential Revision: https://phabricator.haskell.org/D2280
      
      GHC Trac Issues: #10598
      9e862765
  7. 29 Aug, 2016 1 commit
  8. 23 Aug, 2016 1 commit
    • Ryan Scott's avatar
      Template Haskell support for unboxed sums · 613d7455
      Ryan Scott authored
      This adds new constructors `UnboxedSumE`, `UnboxedSumT`, and
      `UnboxedSumP` to represent unboxed sums in Template Haskell.
      
      One thing you can't currently do is, e.g., `reify ''(#||#)`, since I
      don't believe unboxed sum type/data constructors can be written in
      prefix form.  I will look at fixing that as part of #12514.
      
      Fixes #12478.
      
      Test Plan: make test TEST=T12478_{1,2,3}
      
      Reviewers: osa1, goldfire, austin, bgamari
      
      Reviewed By: goldfire, bgamari
      
      Subscribers: thomie
      
      Differential Revision: https://phabricator.haskell.org/D2448
      
      GHC Trac Issues: #12478
      613d7455
  9. 22 Aug, 2016 1 commit
  10. 01 Jul, 2016 1 commit
  11. 06 Jun, 2016 1 commit
    • Alan Zimmerman's avatar
      Merge MatchFixity and HsMatchContext · a13cb279
      Alan Zimmerman authored
      Summary:
      MatchFixity was introduced to facilitate use of API Annotations.
      
      HsMatchContext does the same thing with more detail, but is chased
      through all over the place to provide context when processing a Match.
      
      Since we already have MatchFixity in the Match, it may as well provide
      the full context.
      
      updates submodule haddock
      
      Test Plan: ./validate
      
      Reviewers: austin, goldfire, bgamari
      
      Subscribers: thomie, mpickering
      
      Differential Revision: https://phabricator.haskell.org/D2271
      
      GHC Trac Issues: #12105
      
      (cherry picked from commit 306ecad5)
      a13cb279
  12. 12 May, 2016 1 commit
  13. 02 May, 2016 1 commit
    • Facundo Domínguez's avatar
      StaticPointers: Allow closed vars in the static form. · 36d29f7c
      Facundo Domínguez authored
      Summary:
      With this patch closed variables are allowed regardless of whether
      they are bound at the top level or not.
      
      The FloatOut pass is always performed. When optimizations are
      disabled, only expressions that go to the top level are floated.
      Thus, the applications of the StaticPtr data constructor are always
      floated.
      
      The CoreTidy pass makes sure the floated applications appear in the
      symbol table of object files. It also collects the floated bindings
      and inserts them in the static pointer table.
      
      The renamer does not check anymore if free variables appearing in the
      static form are top-level. Instead, the typechecker looks at the
      tct_closed flag to decide if the free variables are closed.
      
      The linter checks that applications of StaticPtr only occur at the
      top of top-level bindings after the FloatOut pass.
      
      The field spInfoName of StaticPtrInfo has been removed. It used to
      contain the name of the top-level binding that contains the StaticPtr
      application. However, this information is no longer available when the
      StaticPtr is constructed, as the binding name is determined now by the
      FloatOut pass.
      
      Test Plan: ./validate
      
      Reviewers: goldfire, simonpj, austin, hvr, bgamari
      
      Reviewed By: simonpj
      
      Subscribers: thomie, mpickering, mboes
      
      Differential Revision: https://phabricator.haskell.org/D2104
      
      GHC Trac Issues: #11656
      36d29f7c
  14. 17 Apr, 2016 1 commit
  15. 31 Mar, 2016 1 commit
    • Simon Peyton Jones's avatar
      Refactor in TcMatches · bdd90426
      Simon Peyton Jones authored
      * Move the several calls of tauifyMultipleMatches into tcMatches,
        so that it can be called only once, and the invariants are
        clearer
      
      * I discovered in doing this that HsLamCase had a redundant and
        tiresome argument, so I removed it. That in turn allowed some
        modest but nice code simplification
      bdd90426
  16. 15 Mar, 2016 1 commit
    • eir@cis.upenn.edu's avatar
      Fix #11648. · 55577a91
      eir@cis.upenn.edu authored
      We now check that a CUSK is really a CUSK and issue an error if
      it isn't. This also involves more solving and zonking in
      kcHsTyVarBndrs, which was the outright bug reported in #11648.
      
      Test cases: polykinds/T11648{,b}
      
      This updates the haddock submodule.
      
      [skip ci]
      55577a91
  17. 27 Jan, 2016 1 commit
    • eir@cis.upenn.edu's avatar
      Refactor the typechecker to use ExpTypes. · 00cbbab3
      eir@cis.upenn.edu authored
      The idea here is described in [wiki:Typechecker]. Briefly,
      this refactor keeps solid track of "synthesis" mode vs
      "checking" in GHC's bidirectional type-checking algorithm.
      When in synthesis mode, the expected type is just an IORef
      to write to.
      
      In addition, this patch does a significant reworking of
      RebindableSyntax, allowing much more freedom in the types
      of the rebindable operators. For example, we can now have
      `negate :: Int -> Bool` and
      `(>>=) :: m a -> (forall x. a x -> m b) -> m b`. The magic
      is in tcSyntaxOp.
      
      This addresses tickets #11397, #11452, and #11458.
      
      Tests:
        typecheck/should_compile/{RebindHR,RebindNegate,T11397,T11458}
        th/T11452
      00cbbab3
  18. 18 Jan, 2016 1 commit
    • Jan Stolarek's avatar
      Replace calls to `ptext . sLit` with `text` · b8abd852
      Jan Stolarek authored
      Summary:
      In the past the canonical way for constructing an SDoc string literal was the
      composition `ptext . sLit`.  But for some time now we have function `text` that
      does the same.  Plus it has some rules that optimize its runtime behaviour.
      This patch takes all uses of `ptext . sLit` in the compiler and replaces them
      with calls to `text`.  The main benefits of this patch are clener (shorter) code
      and less dependencies between module, because many modules now do not need to
      import `FastString`.  I don't expect any performance benefits - we mostly use
      SDocs to report errors and it seems there is little to be gained here.
      
      Test Plan: ./validate
      
      Reviewers: bgamari, austin, goldfire, hvr, alanz
      
      Subscribers: goldfire, thomie, mpickering
      
      Differential Revision: https://phabricator.haskell.org/D1784
      b8abd852
  19. 16 Jan, 2016 1 commit
    • Alan Zimmerman's avatar
      Work SourceText in for all integer literals · 3a1babd6
      Alan Zimmerman authored
      Summary:
      Certain syntactic elements have integers in them, such as fixity
      specifications, SPECIALISE pragmas and so on.
      
      The lexer will accept mult-radix literals, with arbitrary leading zeros
      in these.
      
      Bring in a SourceText field to each affected AST element to capture the
      original literal text for use with API Annotations.
      
      Affected hsSyn elements are
      
      ```
           -- See note [Pragma source text]
           data Activation = NeverActive
                           | AlwaysActive
                           | ActiveBefore SourceText PhaseNum
                                -- Active only *strictly before* this phase
                           | ActiveAfter SourceText PhaseNum
                                 -- Active in this phase and later
                           deriving( Eq, Data, Typeable )
                                     -- Eq used in comparing rules in HsDecls
      
           data Fixity = Fixity SourceText Int FixityDirection
             -- Note [Pragma source text]
             deriving (Data, Typeable)
       ```
      
      and
      
      ```
            | HsTickPragma         -- A pragma introduced tick
               SourceText           -- Note [Pragma source text] in BasicTypes
               (StringLiteral,(Int,Int),(Int,Int))
                                                -- external span for this tick
               ((SourceText,SourceText),(SourceText,SourceText))
                  -- Source text for the four integers used in the span.
                  -- See note [Pragma source text] in BasicTypes
               (LHsExpr id)
      ```
      
      Updates haddock submodule
      
      Test Plan: ./validate
      
      Reviewers: goldfire, bgamari, austin
      
      Reviewed By: bgamari
      
      Subscribers: thomie, mpickering
      
      Differential Revision: https://phabricator.haskell.org/D1781
      
      GHC Trac Issues: #11430
      3a1babd6
  20. 09 Jan, 2016 1 commit
  21. 06 Jan, 2016 1 commit
  22. 31 Dec, 2015 2 commits
  23. 22 Dec, 2015 3 commits
    • Simon Peyton Jones's avatar
      Refactor named wildcards (again) · 575a98e4
      Simon Peyton Jones authored
      Michal's work on #10982, #11098, refactored the handling of named
      wildcards by making them more like ordinary type variables.
      
      This patch takes the same idea to its logical conclusion, resulting
      in a much tidier, tighter implementation.
      
      Read Note [The wildcard story for types] in HsTypes.
      
      Changes:
      
       * Named wildcards are ordinary type variables, throughout
      
       * HsType no longer has a data constructor for named wildcards
         (was NamedWildCard in HsWildCardInfo).  Named wildcards are
         simply HsTyVars
      
       * Similarly named wildcards disappear from Template Haskell
      
       * I refactored RnTypes to avoid polluting LocalRdrEnv with something
         as narrow as named wildcards.  Instead the named wildcard set is
         carried in RnTyKiEnv.
      
      There is a submodule update for Haddock.
      575a98e4
    • Ryan Scott's avatar
      Rework Template Haskell's handling of strictness · f975b0b1
      Ryan Scott authored
      Currently, Template Haskell's treatment of strictness is not enough to
      cover all possible combinations of unpackedness and strictness. In
      addition, it isn't equipped to deal with new features (such as
      `-XStrictData`) which can change a datatype's fields' strictness during
      compilation.
      
      To address this, I replaced TH's `Strict` datatype with
      `SourceUnpackedness` and `SourceStrictness` (which give the programmer a
      more complete toolkit to configure a datatype field's strictness than
      just `IsStrict`, `IsLazy`, and `Unpack`). I also added the ability to
      reify a constructor fields' strictness post-compilation through the
      `reifyConStrictness` function.
      
      Fixes #10697.
      
      Test Plan: ./validate
      
      Reviewers: simonpj, goldfire, bgamari, austin
      
      Reviewed By: goldfire, bgamari
      
      Subscribers: thomie
      
      Differential Revision: https://phabricator.haskell.org/D1603
      
      GHC Trac Issues: #10697
      f975b0b1
    • Alan Zimmerman's avatar
      Make HsAppsType contents Located · ff923954
      Alan Zimmerman authored
      An HsAppInfix can carry a qconop/varop preceded by a SIMPLEQUOTE as a
      Located RdrName.
      
      In this case AnnSimpleQuote is attached to the Located HsAppType.
      
          | SIMPLEQUOTE qconop            {% ams (sLL $1 $> $ HsAppInfix $2)
                                                 [mj AnnSimpleQuote $1] }
          | SIMPLEQUOTE varop             {% ams (sLL $1 $> $ HsAppInfix $2)
                                                 [mj AnnSimpleQuote $1] }
      
      This patch changes
      
          data HsType name
            ...
            | HsAppsTy [HsAppType name]
      
      to
      
          data HsType name
            ...
            | HsAppsTy [LHsAppType name]
      
      so that the annotation is not discarded when it reaches the ParsedSource
      ff923954
  24. 21 Dec, 2015 2 commits
    • Jan Stolarek's avatar
      Add proper GADTs support to Template Haskell · eeecb864
      Jan Stolarek authored
      Until now GADTs were supported in Template Haskell by encoding them using
      normal data types.  This patch adds proper support for representing GADTs
      in TH.
      
      Test Plan: T10828
      
      Reviewers: goldfire, austin, bgamari
      
      Subscribers: thomie, mpickering
      
      Differential Revision: https://phabricator.haskell.org/D1465
      
      GHC Trac Issues: #10828
      eeecb864
    • Alan Zimmerman's avatar
      Add Location to RdrName in FieldOcc · d8ed20c8
      Alan Zimmerman authored
      Summary:
      Post #11019, there have been some new instances of RdrName that are not
      located, in particular
      
      ```#!hs
      data FieldOcc name = FieldOcc { rdrNameFieldOcc  :: RdrName
                                    , selectorFieldOcc :: PostRn name name
                                    }
      
      data AmbiguousFieldOcc name
        = Unambiguous RdrName (PostRn name name)
        | Ambiguous   RdrName (PostTc name name)
        deriving (Typeable)
      ```
      Add locations to them
      
      Updates haddock submodule to match
      
      Test Plan: ./validate
      
      Reviewers: goldfire, hvr, bgamari, austin
      
      Reviewed By: hvr
      
      Subscribers: hvr, thomie, mpickering
      
      Differential Revision: https://phabricator.haskell.org/D1670
      
      GHC Trac Issues: #11258
      d8ed20c8
  25. 14 Dec, 2015 1 commit
    • Ben Gamari's avatar
      Use Cxt for deriving clauses in TH (#10819) · 04ab55d9
      Ben Gamari authored
      Summary:
      Deriving clauses in the TH representations of data, newtype, data
      instance, and newtype instance declarations previously were just [Name],
      which didn't allow for more complex derived classes, eg. multi-parameter
      typeclasses.
      
      This switches out [Name] for Cxt, representing the derived classes as
      types instead of names.
      
      Test Plan: validate
      
      Reviewers: goldfire, spinda, austin
      
      Reviewed By: goldfire, austin
      
      Subscribers: thomie
      
      Differential Revision: https://phabricator.haskell.org/D1202
      
      GHC Trac Issues: #10819
      04ab55d9
  26. 12 Dec, 2015 1 commit
  27. 11 Dec, 2015 1 commit
    • eir@cis.upenn.edu's avatar
      Add kind equalities to GHC. · 67465497
      eir@cis.upenn.edu authored
      This implements the ideas originally put forward in
      "System FC with Explicit Kind Equality" (ICFP'13).
      
      There are several noteworthy changes with this patch:
       * We now have casts in types. These change the kind
         of a type. See new constructor `CastTy`.
      
       * All types and all constructors can be promoted.
         This includes GADT constructors. GADT pattern matches
         take place in type family equations. In Core,
         types can now be applied to coercions via the
         `CoercionTy` constructor.
      
       * Coercions can now be heterogeneous, relating types
         of different kinds. A coercion proving `t1 :: k1 ~ t2 :: k2`
         proves both that `t1` and `t2` are the same and also that
         `k1` and `k2` are the same.
      
       * The `Coercion` type has been significantly enhanced.
         The documentation in `docs/core-spec/core-spec.pdf` reflects
         the new reality.
      
       * The type of `*` is now `*`. No more `BOX`.
      
       * Users can write explicit kind variables in their code,
         anywhere they can write type variables. For backward compatibility,
         automatic inference of kind-variable binding is still permitted.
      
       * The new extension `TypeInType` turns on the new user-facing
         features.
      
       * Type families and synonyms are now promoted to kinds. This causes
         trouble with parsing `*`, leading to the somewhat awkward new
         `HsAppsTy` constructor for `HsType`. This is dispatched with in
         the renamer, where the kind `*` can be told apart from a
         type-level multiplication operator. Without `-XTypeInType` the
         old behavior persists. With `-XTypeInType`, you need to import
         `Data.Kind` to get `*`, also known as `Type`.
      
       * The kind-checking algorithms in TcHsType have been significantly
         rewritten to allow for enhanced kinds.
      
       * The new features are still quite experimental and may be in flux.
      
       * TODO: Several open tickets: #11195, #11196, #11197, #11198, #11203.
      
       * TODO: Update user manual.
      
      Tickets addressed: #9017, #9173, #7961, #10524, #8566, #11142.
      Updates Haddock submodule.
      67465497
  28. 07 Dec, 2015 1 commit
    • Alan Zimmerman's avatar
      Refactor ConDecl · 51a5e68d
      Alan Zimmerman authored
      The ConDecl type in HsDecls is an uneasy compromise. For the most part,
      HsSyn directly reflects the syntax written by the programmer; and that
      gives just the right "pegs" on which to hang Alan's API annotations. But
      ConDecl doesn't properly reflect the syntax of Haskell-98 and GADT-style
      data type declarations.
      
      To be concrete, here's a draft new data type
      
      ```lang=hs
      data ConDecl name
        | ConDeclGADT
            { con_names   :: [Located name]
            , con_type    :: LHsSigType name  -- The type after the ‘::’
            , con_doc     :: Maybe LHsDocString }
      
        | ConDeclH98
            { con_name    :: Located name
      
            , con_qvars     :: Maybe (LHsQTyVars name)
              -- User-written forall (if any), and its implicit
              -- kind variables
              -- Non-Nothing needs -XExistentialQuantification
      
            , con_cxt       :: Maybe (LHsContext name)
              -- ^ User-written context (if any)
      
            , con_details   :: HsConDeclDetails name
                -- ^ Arguments
      
            , con_doc       :: Maybe LHsDocString
                -- ^ A possible Haddock comment.
            } deriving (Typeable)
      ```
      
      Note that
      
          For GADTs, just keep a type. That's what the user writes.
          NB:HsType can represent records on the LHS of an arrow:
      
            { x:Int,y:Bool} -> T
      
          con_qvars and con_cxt are both Maybe because they are both
          optional (the forall and the context of an existential data type
      
          For ConDeclGADT the type variables of the data type do not scope
          over the con_type; whereas for ConDeclH98 they do scope over con_cxt
          and con_details.
      
      Updates haddock submodule.
      
      Test Plan: ./validate
      
      Reviewers: simonpj, erikd, hvr, goldfire, austin, bgamari
      
      Subscribers: erikd, goldfire, thomie, mpickering
      
      Differential Revision: https://phabricator.haskell.org/D1558
      
      GHC Trac Issues: #11028
      51a5e68d
  29. 01 Dec, 2015 1 commit
    • Simon Peyton Jones's avatar
      Refactor treatment of wildcards · 1e041b73
      Simon Peyton Jones authored
      This patch began as a modest refactoring of HsType and friends, to
      clarify and tidy up exactly where quantification takes place in types.
      Although initially driven by making the implementation of wildcards more
      tidy (and fixing a number of bugs), I gradually got drawn into a pretty
      big process, which I've been doing on and off for quite a long time.
      
      There is one compiler performance regression as a result of all
      this, in perf/compiler/T3064.  I still need to look into that.
      
      * The principal driving change is described in Note [HsType binders]
        in HsType.  Well worth reading!
      
      * Those data type changes drive almost everything else.  In particular
        we now statically know where
      
             (a) implicit quantification only (LHsSigType),
                 e.g. in instance declaratios and SPECIALISE signatures
      
             (b) implicit quantification and wildcards (LHsSigWcType)
                 can appear, e.g. in function type signatures
      
      * As part of this change, HsForAllTy is (a) simplified (no...
      1e041b73
  30. 22 Nov, 2015 1 commit
    • Alan Zimmerman's avatar
      ApiAnnotations: Make all RdrName occurences Located · 3df9563e
      Alan Zimmerman authored
      At the moment the API Annotations can only be used on the ParsedSource,
      as there are changes made to the RenamedSource that prevent it from
      being used to round trip source code.
      
      It is possible to build a map from every Located Name in the
      RenamedSource from its location to the Name, which can then be used when
      resolved names are required when changing the ParsedSource.
      
      However, there are instances where the identifier is not located,
      specifically
      
        (GHC.VarPat name)
        (GHC.HsVar name)
        (GHC.UserTyVar name)
        (GHC.HsTyVar name)
      
      Replace each of the name types above with (Located name)
      
      Updates the haddock submodule.
      
      Test Plan: ./validate
      
      Reviewers: austin, goldfire, bgamari
      
      Reviewed By: bgamari
      
      Subscribers: goldfire, thomie, mpickering
      
      Differential Revision: https://phabricator.haskell.org/D1512
      
      GHC Trac Issues: #11019
      3df9563e
  31. 18 Nov, 2015 1 commit
    • Simon Peyton Jones's avatar
      Refactor HsExpr.RecordCon, RecordUpd · 07eb258d
      Simon Peyton Jones authored
      This follows Matthew's patch making pattern synoyms work
      with records.
      
      This patch
       - replaces the (PostTc id [FieldLabel]) field of
         RecordCon with (PostTc id ConLike)
      
       - record-ises both RecordCon and RecordUpd, which
         both have quite a lot of fields.
      
      No change in behaviour
      07eb258d
  32. 13 Nov, 2015 1 commit
    • Alan Zimmerman's avatar
      APIAnnotations:add Locations in hsSyn for layout · 2290c8bd
      Alan Zimmerman authored
      Summary:
      At the moment ghc-exactprint, which uses the GHC API Annotations to
      provide a framework for roundtripping Haskell source code with optional
      AST edits, has to implement a horrible workaround to manage the points
      where layout needs to be captured.
      
      These are
      
          MatchGroup
          HsDo
          HsCmdDo
          HsLet
          LetStmt
          HsCmdLet
          GRHSs
      
      To provide a more natural representation, the contents subject to layout
      rules need to be wrapped in a SrcSpan.
      
      This commit does this.
      
      Trac ticket #10250
      
      Test Plan: ./validate
      
      Reviewers: hvr, goldfire, bgamari, austin, mpickering
      
      Reviewed By: mpickering
      
      Subscribers: thomie, mpickering
      
      Differential Revision: https://phabricator.haskell.org/D1370
      
      GHC Trac Issues: #10250
      2290c8bd
  33. 11 Nov, 2015 1 commit
    • Alan Zimmerman's avatar
      Remove fun_infix from Funbind, as it is now in Match · f0f9365f
      Alan Zimmerman authored
      One of the changes D538 introduced is to add `m_fun_id_infix` to `Match`
      
      ```lang=hs
      data Match id body
        = Match {
              m_fun_id_infix :: (Maybe (Located id,Bool)),
                -- fun_id and fun_infix for functions with multiple equations
                -- only present for a RdrName. See note [fun_id in Match]
              m_pats :: [LPat id], -- The patterns
              m_type :: (Maybe (LHsType id)),
                                       -- A type signature for the result of the match
                                       -- Nothing after typechecking
              m_grhss :: (GRHSs id body)
        } deriving (Typeable)
      ```
      
      This was done to track the individual locations and fixity of the
      `fun_id` for each of the defining equations for a function when there
      are more than one.
      
      For example, the function `(&&&)` is defined with some prefix and some
      infix equations below.
      
      ```lang=hs
          (&&&  ) [] [] =  []
          xs    &&&   [] =  xs
          (  &&&  ) [] ys =  ys
      ```
      
      This means that the fun_infix is now superfluous in the `FunBind`. This
      has not been removed as a potentially risky change just before 7.10 RC2,
      and so must be done after.
      
      This ticket captures that task, which includes processing these fields
      through the renamer and beyond.
      
      Ticket #9988 introduced these fields into `Match` through renaming, this
      ticket it to continue through type checking and then remove it from
      `FunBind` completely.
      
      The split happened so that #9988 could land in 7.10
      
      Trac ticket : #10061
      
      Test Plan: ./validate
      
      Reviewers: goldfire, austin, simonpj, bgamari
      
      Reviewed By: bgamari
      
      Subscribers: simonpj, thomie, mpickering
      
      Differential Revision: https://phabricator.haskell.org/D1285
      
      GHC Trac Issues: #10061
      f0f9365f
  34. 07 Nov, 2015 1 commit
    • Matthew Pickering's avatar
      Remove PatSynBuilderId · 22080113
      Matthew Pickering authored
      Summary:
      It was only used to pass field labels between the typechecker and
      desugarer. Instead we add an extra field the RecordCon to carry this
      information.
      
      Reviewers: austin, goldfire, bgamari
      
      Reviewed By: bgamari
      
      Subscribers: thomie
      
      Differential Revision: https://phabricator.haskell.org/D1443
      
      GHC Trac Issues: #11057
      22080113
  35. 29 Oct, 2015 1 commit
    • Matthew Pickering's avatar
      Record pattern synonyms · 2a74a64e
      Matthew Pickering authored
      This patch implements an extension to pattern synonyms which allows user
      to specify pattern synonyms using record syntax. Doing so generates
      appropriate selectors and update functions.
      
      === Interaction with Duplicate Record Fields ===
      
      The implementation given here isn't quite as general as it could be with
      respect to the recently-introduced `DuplicateRecordFields` extension.
      
      Consider the following module:
      
          {-# LANGUAGE DuplicateRecordFields #-}
          {-# LANGUAGE PatternSynonyms #-}
      
          module Main where
      
          pattern S{a, b} = (a, b)
          pattern T{a}    = Just a
      
          main = do
            print S{ a = "fst", b = "snd" }
            print T{ a = "a" }
      
      In principle, this ought to work, because there is no ambiguity. But at
      the moment it leads to a "multiple declarations of a" error. The problem
      is that pattern synonym record selectors don't do the same name mangling
      as normal datatypes when DuplicateRecordFields is enabled. They could,
      but this would require some work to track the field label and selector
      name separately.
      
      In particular, we currently represent datatype selectors in the third
      component of AvailTC, but pattern synonym selectors are just represented
      as Avails (because they don't have a corresponding type constructor).
      Moreover, the GlobalRdrElt for a selector currently requires it to have
      a parent tycon.
      
      (example due to Adam Gundry)
      
      === Updating Explicitly Bidirectional Pattern Synonyms ===
      
      Consider the following
      
      ```
      pattern Silly{a} <- [a] where
        Silly a = [a, a]
      
      f1 = a [5] -- 5
      
      f2 = [5] {a = 6} -- currently [6,6]
      ```
      
      === Fixing Polymorphic Updates ===
      
      They were fixed by adding these two lines in `dsExpr`. This might break
      record updates but will be easy to fix.
      
      ```
      + ; let req_wrap = mkWpTyApps (mkTyVarTys univ_tvs)
      
      - , pat_wrap = idHsWrapper }
      +, pat_wrap = req_wrap }
      ```
      
      === Mixed selectors error ===
      
      Note [Mixed Record Field Updates]
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      
      Consider the following pattern synonym.
      
          data MyRec = MyRec { foo :: Int, qux :: String }
      
          pattern HisRec{f1, f2} = MyRec{foo = f1, qux=f2}
      
      This allows updates such as the following
      
          updater :: MyRec -> MyRec
          updater a = a {f1 = 1 }
      
      It would also make sense to allow the following update (which we
      reject).
      
          updater a = a {f1 = 1, qux = "two" } ==? MyRec 1 "two"
      
      This leads to confusing behaviour when the selectors in fact refer the
      same field.
      
          updater a = a {f1 = 1, foo = 2} ==? ???
      
      For this reason, we reject a mixture of pattern synonym and normal
      record selectors in the same update block. Although of course we still
      allow the following.
      
          updater a = (a {f1 = 1}) {foo = 2}
      
          > updater (MyRec 0 "str")
          MyRec 2 "str"
      2a74a64e
  36. 17 Oct, 2015 1 commit
    • Herbert Valerio Riedel's avatar
      Make Monad/Applicative instances MRP-friendly · e8ed2136
      Herbert Valerio Riedel authored
      This patch refactors pure/(*>) and return/(>>) in MRP-friendly way, i.e.
      such that the explicit definitions for `return` and `(>>)` match the
      MRP-style default-implementation, i.e.
      
        return = pure
      
      and
      
        (>>) = (*>)
      
      This way, e.g. all `return = pure` definitions can easily be grepped and
      removed in GHC 8.1;
      
      Test Plan: Harbormaster
      
      Reviewers: goldfire, alanz, bgamari, quchen, austin
      
      Reviewed By: quchen, austin
      
      Subscribers: thomie
      
      Differential Revision: https://phabricator.haskell.org/D1312
      e8ed2136