1. 14 Apr, 2015 2 commits
    • Simon Peyton Jones's avatar
      Comments only · 25f2d688
      Simon Peyton Jones authored
      25f2d688
    • Alan Zimmerman's avatar
      parser: opt_kind_sig has incorrect SrcSpan · 8aefc9b7
      Alan Zimmerman authored
      The production for opt_kind_sig is
      
        opt_kind_sig :: { Located (Maybe (LHsKind RdrName)) }
                :                             { noLoc Nothing }
                | '::' kind                   {% ajl (sLL $1 $> (Just $2)) AnnDcolon (gl $1) }
      
      The outer Location is used only to get the full span for the enclosing
      declration, and is then stripped. The inner LHsKind then has a SrcSpan that does
      not include the '::'
      
      Extend the SrcSpan on $2 to include $1
      
      Reviewed By: austin
      
      Differential Revision: https://phabricator.haskell.org/D813
      
      GHC Trac Issues: #10209
      8aefc9b7
  2. 10 Feb, 2015 1 commit
    • Simon Peyton Jones's avatar
      Refactor the handling of quasi-quotes · f46360ed
      Simon Peyton Jones authored
      As Trac #10047 points out, a quasi-quotation [n|...blah...|] is supposed
      to behave exactly like $(n "...blah...").  But it doesn't!  This was outright
      wrong: quasiquotes were being run even inside brackets.
      
      Now that TH supports both typed and untyped splices, a quasi-quote is properly
      regarded as a particular syntax for an untyped splice. But apart from that
      they should be treated the same.  So this patch refactors the handling of
      quasiquotes to do just that.
      
      The changes touch quite a lot of files, but mostly in a routine way.
      The biggest changes by far are in RnSplice, and more minor changes in
      TcSplice.  These are the places where there was real work to be done.
      Everything else is routine knock-on changes.
      
      * No more QuasiQuote forms in declarations, expressions, types, etc.
        So we get rid of these data constructors
          * HsBinds.QuasiQuoteD
          * HsExpr.HsSpliceE
          * HsPat.QuasiQuotePat
          * HsType.HsQuasiQuoteTy
      
      * We get rid of the HsQuasiQuote type altogether
      
      * Instead, we augment the HsExpr.HsSplice type to have three
        consructors, for the three types of splice:
          * HsTypedSplice
          * HsUntypedSplice
          * HsQuasiQuote
        There are some related changes in the data types in HsExpr near HsSplice.
        Specifically: PendingRnSplice, PendingTcSplice, UntypedSpliceFlavour.
      
      * In Hooks, we combine rnQuasiQuoteHook and rnRnSpliceHook into one.
        A smaller, clearer interface.
      
      * We have to update the Haddock submodule, to accommodate the hsSyn changes
      f46360ed
  3. 19 Jan, 2015 1 commit
    • Alan Zimmerman's avatar
      API Annotations documentation update, parsing issue, add example test · 851ed721
      Alan Zimmerman authored
      Summary:
      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
      851ed721
  4. 16 Jan, 2015 1 commit
    • Alan Zimmerman's avatar
      API Annotations tweaks. · 11881ec6
      Alan Zimmerman authored
      Summary:
      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
      11881ec6
  5. 08 Jan, 2015 1 commit
    • Simon Peyton Jones's avatar
      Improve HsBang · 9564bb8c
      Simon Peyton Jones authored
      Provoked by questions from Johan
      
       - Improve comments, fix misleading stuff
       - Add commented synonyms for HsSrcBang, HsImplBang, and use them throughout
       - Rename HsUserBang to HsSrcBang
       - Rename dataConStrictMarks to dataConSrcBangs
                dataConRepBangs    to dataConImplBangs
      
      This renaming affects Haddock in a trivial way, hence submodule update
      9564bb8c
  6. 30 Dec, 2014 1 commit
  7. 03 Dec, 2014 1 commit
  8. 01 Dec, 2014 1 commit
  9. 30 Nov, 2014 1 commit
  10. 28 Nov, 2014 1 commit
  11. 21 Nov, 2014 2 commits
    • Alan Zimmerman's avatar
      Add API Annotations · 803fc5db
      Alan Zimmerman authored
      Summary:
      The final design and discussion is captured at
      https://ghc.haskell.org/trac/ghc/wiki/GhcAstAnnotations
      
      This is a proof of concept implementation of a completely
      separate annotation structure, populated in the parser,and tied to the
      AST by means of a virtual "node-key" comprising the surrounding
      SrcSpan and a value derived from the specific constructor used for the
      node.
      
      The key parts of the design are the following.
      
      == The Annotations ==
      
      In `hsSyn/ApiAnnotation.hs`
      
      ```lang=haskell
      type ApiAnns = (Map.Map ApiAnnKey SrcSpan, Map.Map SrcSpan [Located Token])
      
      type ApiAnnKey = (SrcSpan,AnnKeywordId)
      
      -- ---------------------------------------------------------------------
      
      -- | Retrieve an annotation based on the @SrcSpan@ of the annotated AST
      -- element, and the known type of the annotation.
      getAnnotation :: ApiAnns -> SrcSpan -> AnnKeywordId -> Maybe SrcSpan
      getAnnotation (anns,_) span ann = Map.lookup (span,ann) anns
      
      -- |Retrieve the comments allocated to the current @SrcSpan@
      getAnnotationComments :: ApiAnns -> SrcSpan -> [Located Token]
      getAnnotationComments (_,anns) span =
        case Map.lookup span anns of
          Just cs -> cs
          Nothing -> []
      
      -- | Note: in general the names of these are taken from the
      -- corresponding token, unless otherwise noted
      data AnnKeywordId
               = AnnAs
               | AnnBang
               | AnnClass
               | AnnClose -- ^ } or ] or ) or #) etc
               | AnnComma
               | AnnDarrow
               | AnnData
               | AnnDcolon
               ....
      ```
      
      == Capturing in the lexer/parser ==
      
      The annotations are captured in the lexer / parser by extending PState to include a field
      
      In `parser/Lexer.x`
      
      ```lang=haskell
      data PState = PState {
              ....
              annotations :: [(ApiAnnKey,SrcSpan)]
              -- Annotations giving the locations of 'noise' tokens in the
              -- source, so that users of the GHC API can do source to
              -- source conversions.
           }
      ```
      
      The lexer exposes a helper function to add an annotation
      
      ```lang=haskell
      addAnnotation :: SrcSpan -> Ann -> SrcSpan -> P ()
      addAnnotation l a v = P $ \s -> POk s {
        annotations = ((AK l a), v) : annotations s
        } ()
      
      ```
      
      The parser also has some helper functions of the form
      
      ```lang=haskell
      type MaybeAnn = Maybe (SrcSpan -> P ())
      
      gl = getLoc
      gj x = Just (gl x)
      
      ams :: Located a -> [MaybeAnn] -> P (Located a)
      ams a@(L l _) bs = (mapM_ (\a -> a l) $ catMaybes bs) >> return a
      ```
      
      This allows annotations to be captured in the parser by means of
      
      ```
      ctypedoc :: { LHsType RdrName }
              : 'forall' tv_bndrs '.' ctypedoc {% hintExplicitForall (getLoc $1) >>
                                                  ams (LL $ mkExplicitHsForAllTy $2 (noLoc []) $4)
                                                      [mj AnnForall $1,mj AnnDot $3] }
              | context '=>' ctypedoc         {% ams (LL $ mkQualifiedHsForAllTy   $1 $3)
                                                     [mj AnnDarrow $2] }
              | ipvar '::' type               {% ams (LL (HsIParamTy (unLoc $1) $3))
                                                     [mj AnnDcolon $2] }
              | typedoc                       { $1 }
      ```
      
      == Parse result ==
      
      ```lang-haskell
      data HsParsedModule = HsParsedModule {
          hpm_module    :: Located (HsModule RdrName),
          hpm_src_files :: [FilePath],
             -- ^ extra source files (e.g. from #includes).  The lexer collects
             -- these from '# <file> <line>' pragmas, which the C preprocessor
             -- leaves behind.  These files and their timestamps are stored in
             -- the .hi file, so that we can force recompilation if any of
             -- them change (#3589)
          hpm_annotations :: ApiAnns
        }
      
      -- | The result of successful parsing.
      data ParsedModule =
        ParsedModule { pm_mod_summary   :: ModSummary
                     , pm_parsed_source :: ParsedSource
                     , pm_extra_src_files :: [FilePath]
                     , pm_annotations :: ApiAnns }
      ```
      
      This diff depends on D426
      
      Test Plan: sh ./validate
      
      Reviewers: austin, simonpj, Mikolaj
      
      Reviewed By: simonpj, Mikolaj
      
      Subscribers: Mikolaj, goldfire, thomie, carter
      
      Differential Revision: https://phabricator.haskell.org/D438
      
      GHC Trac Issues: #9628
      803fc5db
    • Alan Zimmerman's avatar
      AST changes to prepare for API annotations, for #9628 · 7927658e
      Alan Zimmerman authored
      Summary:
      AST changes to prepare for API annotations
      
      Add locations to parts of the AST so that API annotations can
      then be added.
      
      The outline of the whole process is captured here
      https://ghc.haskell.org/trac/ghc/wiki/GhcAstAnnotations
      
      This change updates the haddock submodule.
      
      Test Plan: sh ./validate
      
      Reviewers: austin, simonpj, Mikolaj
      
      Reviewed By: simonpj, Mikolaj
      
      Subscribers: thomie, goldfire, carter
      
      Differential Revision: https://phabricator.haskell.org/D426
      
      GHC Trac Issues: #9628
      7927658e
  12. 20 Nov, 2014 1 commit
    • Gergő Érdi's avatar
      Add support for pattern synonym type signatures. · cce6318e
      Gergő Érdi authored
      Syntax is of the form
      
          pattern P :: (Prov b) => (Req a) => a -> b -> Int -> T a
      
      which declares a pattern synonym called `P`, with argument types `a`, `b`,
      and `Int`, and result type `T a`, with provided context `(Prov b)` and required
      context `(Req a)`.
      
      The Haddock submodule is also updated to use this new syntax in generated docs.
      cce6318e
  13. 18 Sep, 2014 1 commit
    • Krzysztof Gogolewski's avatar
      Add -fwarn-context-quantification (#4426) · 275dcafb
      Krzysztof Gogolewski authored
      Summary:
      This warning (enabled by default) reports places where a context
      implicitly binds a type variable, for example
      
      type T a = {-forall m.-} Monad m => a -> m a
      
      Also update Haddock submodule.
      
      Test Plan: validate
      
      Reviewers: hvr, goldfire, simonpj, austin
      
      Reviewed By: austin
      
      Subscribers: simonmar, ezyang, carter
      
      Differential Revision: https://phabricator.haskell.org/D211
      
      GHC Trac Issues: #4426
      275dcafb
  14. 06 Sep, 2014 1 commit
  15. 12 Aug, 2014 2 commits
  16. 20 Jun, 2014 1 commit
    • Simon Peyton Jones's avatar
      Tidy up the printing of single-predicate contexts · 0ceb84e9
      Simon Peyton Jones authored
      This covers things like
         Eq a => blah   and   (?x::Int) => blah
      where there is just one predicate. Previously we used an ad-hoc
      test to decide whether to parenthesise it, but acutally there is
      a much simpler solution: just use the existing precedence mechamism.
      
      This applies both to Type and HsType.
      0ceb84e9
  17. 06 Jun, 2014 1 commit
  18. 05 Jun, 2014 1 commit
  19. 12 May, 2014 1 commit
  20. 20 Jan, 2014 1 commit
    • Gergő Érdi's avatar
      Implement pattern synonyms · 4f8369bf
      Gergő Érdi authored
      This patch implements Pattern Synonyms (enabled by -XPatternSynonyms),
      allowing y ou to assign names to a pattern and abstract over it.
      
      The rundown is this:
      
        * Named patterns are introduced by the new 'pattern' keyword, and can
          be either *unidirectional* or *bidirectional*. A unidirectional
          pattern is, in the simplest sense, simply an 'alias' for a pattern,
          where the LHS may mention variables to occur in the RHS. A
          bidirectional pattern synonym occurs when a pattern may also be used
          in expression context.
      
        * Unidirectional patterns are declared like thus:
      
              pattern P x <- x:_
      
          The synonym 'P' may only occur in a pattern context:
      
              foo :: [Int] -> Maybe Int
              foo (P x) = Just x
              foo _     = Nothing
      
        * Bidirectional patterns are declared like thus:
      
              pattern P x y = [x, y]
      
          Here, P may not only occur as a pattern, but also as an expression
          when given values for 'x' and 'y', i.e.
      
              bar :: Int -> [Int]
              bar x = P x 10
      
        * Patterns can't yet have their own type signatures; signatures are inferred.
      
        * Pattern synonyms may not be recursive, c.f. type synonyms.
      
        * Pattern synonyms are also exported/imported using the 'pattern'
          keyword in an import/export decl, i.e.
      
              module Foo (pattern Bar) where ...
      
          Note that pattern synonyms share the namespace of constructors, so
          this disambiguation is required as a there may also be a 'Bar'
          type in scope as well as the 'Bar' pattern.
      
        * The semantics of a pattern synonym differ slightly from a typical
          pattern: when using a synonym, the pattern itself is matched,
          followed by all the arguments. This means that the strictness
          differs slightly:
      
              pattern P x y <- [x, y]
      
              f (P True True) = True
              f _             = False
      
              g [True, True] = True
              g _            = False
      
          In the example, while `g (False:undefined)` evaluates to False,
          `f (False:undefined)` results in undefined as both `x` and `y`
          arguments are matched to `True`.
      
      For more information, see the wiki:
      
          https://ghc.haskell.org/trac/ghc/wiki/PatternSynonyms
          https://ghc.haskell.org/trac/ghc/wiki/PatternSynonyms/Implementation
      
      Reviewed-by: Simon Peyton Jones's avatarSimon Peyton Jones <simonpj@microsoft.com>
      Signed-off-by: default avatarAustin Seipp <austin@well-typed.com>
      4f8369bf
  21. 10 Jan, 2014 1 commit
  22. 25 Nov, 2013 1 commit
    • Simon Peyton Jones's avatar
      Another raft of Template Haskell clean-up · 51deeb0d
      Simon Peyton Jones authored
      The handling of typed and untyped brackets was extremely convoluted,
      partly because of the evolutionary history.  I've tidied it all up.
      
      See Note [How brackets and nested splices are handled] in TcSplice
      for the full story
      
      Main changes:
      
       * Untyped brackets: after the renamer, HsRnBracketOut carries
         PendingRnSplices for splices in untyped brackets.  In the
         typechecker, these pending splices are typechecked quite
         straigtforwardly, with no ps_var nonsense.
      
       * Typed brackets: after the renamer typed brackest still look
         like HsBracket. The type checker does the ps_var thing.
      
       * In TcRnTypes.ThStage, the Brack constructor, we distinguish
         the renaming from typehecking pending-stuff.  Much more
         perspicuous!
      
       * The "typed" flag is in HsSpliceE, not in HsSplice, because
         only expressions can be typed.  Patterns, types, declarations
         cannot.
      
      There is further improvement to be done to make the handling of
      declaration splices more uniform.
      51deeb0d
  23. 18 Sep, 2013 1 commit
    • eir@cis.upenn.edu's avatar
      Change role annotation syntax. · f4046b50
      eir@cis.upenn.edu authored
      This fixes bugs #8185, #8234, and #8246. The new syntax is explained
      in the comments to #8185, appears in the "Roles" subsection of the
      manual, and on the [wiki:Roles] wiki page.
      
      This change also removes the ability for a role annotation on type
      synonyms, as noted in #8234.
      f4046b50
  24. 04 Aug, 2013 1 commit
    • eir@cis.upenn.edu's avatar
      Refactor checking for GADT-like datacons' return types · 3cd1360f
      eir@cis.upenn.edu authored
      This check is somewhat subtle. See Note [Checking GADT return types]
      in TcTyClsDecls. The new plan is to check *before* desugaring the type
      from HsType to Type. This avoids problems with the pattern-match
      in rejigConRes.
      
      As a nice side benefit to this, I discovered that Template Haskell
      splices were a little conservative in their treatment of valid data
      constructors. (For example, a kind signature in the return type caused
      failure.) Now, the TH code uses exactly the same function as the
      "real" code, which is nice. See hsTyGetAppHead_maybe in HsTypes.
      3cd1360f
  25. 02 Aug, 2013 1 commit
  26. 15 May, 2013 1 commit
  27. 03 May, 2013 1 commit
    • Simon Peyton Jones's avatar
      Fix kind quantification (again) · 7a7530a9
      Simon Peyton Jones authored
      We simply weren't quantifying kind variables at the points we
      were claiming.  In paritcular, in
           forall (a:k). blah
      we quantify the 'k' around the 'forall a', provided k isn't
      already in scope
      7a7530a9
  28. 14 Feb, 2013 1 commit
  29. 24 Jan, 2013 1 commit
  30. 23 Dec, 2012 1 commit
    • Simon Peyton Jones's avatar
      Make {-# UNPACK #-} work for type/data family invocations · 1ee1cd41
      Simon Peyton Jones authored
      This fixes most of Trac #3990.  Consider
        data family D a
        data instance D Double = CD Int Int
        data T = T {-# UNPACK #-} !(D Double)
      Then we want the (D Double unpacked).
      
      To do this we need to construct a suitable coercion, and it's much
      safer to record that coercion in the interface file, lest the in-scope
      instances differ somehow.  That in turn means elaborating the HsBang
      type to include a coercion.
      
      To do that I moved HsBang from BasicTypes to DataCon, which caused
      quite a few minor knock-on changes.
      
      Interface-file format has changed!
      
      Still to do: need to do knot-tying to allow instances to take effect
      within the same module.
      1ee1cd41
  31. 10 Jul, 2012 1 commit
  32. 13 Jun, 2012 1 commit
    • Simon Peyton Jones's avatar
      Simplify the implementation of Implicit Parameters · 5a8ac0f8
      Simon Peyton Jones authored
      This patch re-implements implicit parameters via a class
      with a functional dependency:
      
          class IP (n::Symbol) a | n -> a where
            ip :: a
      
      This definition is in the library module GHC.IP. Notice
      how it use a type-literal, so we can have constraints like
         IP "x" Int
      Now all the functional dependency machinery works right to make
      implicit parameters behave as they should.
      
      Much special-case processing for implicit parameters can be removed
      entirely. One particularly nice thing is not having a dedicated
      "original-name cache" for implicit parameters (the nsNames field of
      NameCache).  But many other cases disappear:
      
        * BasicTypes.IPName
        * IPTyCon constructor in Tycon.TyCon
        * CIPCan constructor  in TcRnTypes.Ct
        * IPPred constructor  in Types.PredTree
      
      Implicit parameters remain special in a few ways:
      
       * Special syntax.  Eg the constraint (IP "x" Int) is parsed
         and printed as (?x::Int).  And we still have local bindings
         for implicit parameters, and occurrences thereof.
      
       * A implicit-parameter binding  (let ?x = True in e) amounts
         to a local instance declaration, which we have not had before.
         It just generates an implication contraint (easy), but when
         going under it we must purge any existing bindings for
         ?x in the inert set.  See Note [Shadowing of Implicit Parameters]
         in TcSimplify
      
       * TcMType.sizePred classifies implicit parameter constraints as size-0,
         as before the change
      
      There are accompanying patches to libraries 'base' and 'haddock'
      
      All the work was done by Iavor Diatchki
      5a8ac0f8
  33. 29 May, 2012 1 commit
  34. 22 May, 2012 1 commit
  35. 11 May, 2012 1 commit
    • Simon Peyton Jones's avatar
      Refactor LHsTyVarBndrs to fix Trac #6081 · fc8959ac
      Simon Peyton Jones authored
      This is really a small change, but it touches a lot of files quite
      significantly. The real goal is to put the implicitly-bound kind
      variables of a data/class decl in the right place, namely on the
      LHsTyVarBndrs type, which now looks like
      
        data LHsTyVarBndrs name
          = HsQTvs { hsq_kvs :: [Name]
                   , hsq_tvs :: [LHsTyVarBndr name]
            }
      
      This little change made the type checker neater in a number of
      ways, but it was fiddly to push through the changes.
      fc8959ac
  36. 20 Apr, 2012 1 commit
    • Simon Peyton Jones's avatar
      Do SCC on instance declarations (fixes Trac #5715) · fa9fdc28
      Simon Peyton Jones authored
      The trouble here is that given
      
          {-# LANGUAGE DataKinds, TypeFamilies #-}
          data instance Foo a = Bar (Bar a)
      
      we want to get a sensible message that we can't use the promoted 'Bar'
      constructor until after its definition; it's a staging error.  Bud the
      staging mechanism that we use for vanilla data declarations don't work
      here.
      
      Solution is to perform strongly-connected component analysis on the
      instance declarations. But that in turn means that we need to track
      free-variable information on more HsSyn declarations, which is why
      so many files are touched.  All the changes are boiler-platey except
      the ones in TcInstDcls.
      fa9fdc28
  37. 13 Apr, 2012 1 commit
    • Simon Peyton Jones's avatar
      Allow kind-variable binders in type signatures · c5554f82
      Simon Peyton Jones authored
      This is the last major addition to the kind-polymorphism story,
      by allowing (Trac #5938)
      
       type family F a   -- F :: forall k. k -> *
       data T a          -- T :: forall k. k -> *
       type instance F (T (a :: Maybe k)) = Char
      
      The new thing is the explicit 'k' in the type signature on 'a',
      which itself is inside a type pattern for F.
      
      Main changes are:
      
      * HsTypes.HsBSig now has a *pair* (kvs, tvs) of binders,
        the kind variables and the type variables
      
      * extractHsTyRdrTyVars returns a pair (kvs, tvs)
        and the function itself has moved from RdrHsSyn to RnTypes
      
      * Quite a bit of fiddling with
           TcHsType.tcHsPatSigType and tcPatSig
        which have become a bit simpler.  I'm still not satisfied
        though.  There's some consequential fiddling in TcRules too.
      
      * Removed the unused HsUtils.collectSigTysFromPats
      
      There's a consequential wibble to Haddock too
      c5554f82