1. 27 Jan, 2016 2 commits
    • 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
    • Ömer Sinan Ağacan's avatar
      s/unLifted/unlifted for consistency · 4faa1a63
      Ömer Sinan Ağacan authored
      This was causing trouble as we had to remember when to use "unLifted"
      and when to use "unlifted".
      
      "unlifted" is used instead of "unLifted" as it's a single word.
      
      Reviewers: austin, hvr, goldfire, bgamari
      
      Subscribers: thomie
      
      Differential Revision: https://phabricator.haskell.org/D1852
      4faa1a63
  2. 23 Jan, 2016 1 commit
  3. 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
  4. 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
  5. 15 Jan, 2016 1 commit
    • eir@cis.upenn.edu's avatar
      Fix #11405. · 3c6635ef
      eir@cis.upenn.edu authored
      This adds a new variant of AbsBinds that is used solely for bindings
      with a type signature. This allows for a simpler desugaring that
      does not produce the bogus output that tripped up Core Lint in
      ticket #11405. Should make other desugarings simpler, too.
      3c6635ef
  6. 08 Jan, 2016 1 commit
    • Simon Marlow's avatar
      Enable stack traces with ghci -fexternal-interpreter -prof · 6be09e88
      Simon Marlow authored
      Summary:
      The main goal here is enable stack traces in GHCi.  After this change,
      if you start GHCi like this:
      
        ghci -fexternal-interpreter -prof
      
      (which requires packages to be built for profiling, but not GHC
      itself) then the interpreter manages cost-centre stacks during
      execution and can produce a stack trace on request.  Call locations
      are available for all interpreted code, and any compiled code that was
      built with the `-fprof-auto` familiy of flags.
      
      There are a couple of ways to get a stack trace:
      
      * `error`/`undefined` automatically get one attached
      * `Debug.Trace.traceStack` can be used anywhere, and prints the current
        stack
      
      Because the interpreter is running in a separate process, only the
      interpreted code is running in profiled mode and the compiler itself
      isn't slowed down by profiling.
      
      The GHCi debugger still doesn't work with -fexternal-interpreter,
      although this patch gets it a step closer.  Most of the functionality
      of breakpoints is implemented, but the runtime value introspection is
      still not supported.
      
      Along the way I also did some refactoring and added type arguments to
      the various remote pointer types in `GHCi.RemotePtr`, so there's
      better type safety and documentation in the bridge code between GHC
      and ghc-iserv.
      
      Test Plan: validate
      
      Reviewers: bgamari, ezyang, austin, hvr, goldfire, erikd
      
      Subscribers: thomie
      
      Differential Revision: https://phabricator.haskell.org/D1747
      
      GHC Trac Issues: #11047, #11100
      6be09e88
  7. 31 Dec, 2015 1 commit
  8. 24 Dec, 2015 1 commit
    • eir@cis.upenn.edu's avatar
      Visible type application · 2db18b81
      eir@cis.upenn.edu authored
      This re-working of the typechecker algorithm is based on
      the paper "Visible type application", by Richard Eisenberg,
      Stephanie Weirich, and Hamidhasan Ahmed, to be published at
      ESOP'16.
      
      This patch introduces -XTypeApplications, which allows users
      to say, for example `id @Int`, which has type `Int -> Int`. See
      the changes to the user manual for details.
      
      This patch addresses tickets #10619, #5296, #10589.
      2db18b81
  9. 21 Dec, 2015 1 commit
    • Simon Marlow's avatar
      Maintain cost-centre stacks in the interpreter · c8c44fd9
      Simon Marlow authored
      Summary:
      Breakpoints become SCCs, so we have detailed call-stack info for
      interpreted code.  Currently this only works when GHC is compiled with
      -prof, but D1562 (Remote GHCi) removes this constraint so that in the
      future call stacks will be available without building your own GHCi.
      
      How can you get a stack trace?
      
      * programmatically: GHC.Stack.currentCallStack
      * I've added an experimental :where command that shows the stack when
        stopped at a breakpoint
      * `error` attaches a call stack automatically, although since calls to
        `error` are often lifted out to the top level, this is less useful
        than it might be (ImplicitParams still works though).
      * Later we might attach call stacks to all exceptions
      
      Other related changes in this diff:
      
      * I reduced the number of places that get ticks attached for
        breakpoints.  In particular there was a breakpoint around the whole
        declaration, which was often redundant because it bound no variables.
        This reduces clutter in the stack traces and speeds up compilation.
      
      * I tidied up some RealSrcSpan stuff in InteractiveUI, and made a few
        other small cleanups
      
      Test Plan: validate
      
      Reviewers: ezyang, bgamari, austin, hvr
      
      Subscribers: thomie
      
      Differential Revision: https://phabricator.haskell.org/D1595
      
      GHC Trac Issues: #11047
      c8c44fd9
  10. 17 Dec, 2015 1 commit
    • Simon Marlow's avatar
      Remote GHCi, -fexternal-interpreter · 4905b83a
      Simon Marlow authored
      Summary:
      (Apologies for the size of this patch, I couldn't make a smaller one
      that was validate-clean and also made sense independently)
      
      (Some of this code is derived from GHCJS.)
      
      This commit adds support for running interpreted code (for GHCi and
      TemplateHaskell) in a separate process.  The functionality is
      experimental, so for now it is off by default and enabled by the flag
      -fexternal-interpreter.
      
      Reaosns we want this:
      
      * compiling Template Haskell code with -prof does not require
        building the code without -prof first
      
      * when GHC itself is profiled, it can interpret unprofiled code, and
        the same applies to dynamic linking.  We would no longer need to
        force -dynamic-too with TemplateHaskell, and we can load ordinary
        objects into a dynamically-linked GHCi (and vice versa).
      
      * An unprofiled GHCi can load and run profiled code, which means it
        can use the stack-trace functionality provided by profiling without
        taking the performance hit on the compiler that profiling would
        entail.
      
      Amongst other things; see
      https://ghc.haskell.org/trac/ghc/wiki/RemoteGHCi for more details.
      
      Notes on the implementation are in Note [Remote GHCi] in the new
      module compiler/ghci/GHCi.hs.  It probably needs more documenting,
      feel free to suggest things I could elaborate on.
      
      Things that are not currently implemented for -fexternal-interpreter:
      
      * The GHCi debugger
      * :set prog, :set args in GHCi
      * `recover` in Template Haskell
      * Redirecting stdin/stdout for the external process
      
      These are all doable, I just wanted to get to a working validate-clean
      patch first.
      
      I also haven't done any benchmarking yet.  I expect there to be slight hit
      to link times for byte code and some penalty due to having to
      serialize/deserialize TH syntax, but I don't expect it to be a serious
      problem.  There's also lots of low-hanging fruit in the byte code
      generator/linker that we could exploit to speed things up.
      
      Test Plan:
      * validate
      * I've run parts of the test suite with
      EXTRA_HC_OPTS=-fexternal-interpreter, notably tests/ghci and tests/th.
      There are a few failures due to the things not currently implemented
      (see above).
      
      Reviewers: simonpj, goldfire, ezyang, austin, alanz, hvr, niteria, bgamari, gibiansky, luite
      
      Subscribers: thomie
      
      Differential Revision: https://phabricator.haskell.org/D1562
      4905b83a
  11. 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 wildcards)
        and (b) split into HsForAllTy and HsQualTy.  The two contructors
        appear when and only when the correponding user-level construct
        appears.  Again see Note [HsType binders].
      
        HsExplicitFlag disappears altogether.
      
      * Other simplifications
      
           - ExprWithTySig no longer needs an ExprWithTySigOut variant
      
           - TypeSig no longer needs a PostRn name [name] field
             for wildcards
      
           - PatSynSig records a LHsSigType rather than the decomposed
             pieces
      
           - The mysterious 'GenericSig' is now 'ClassOpSig'
      
      * Renamed LHsTyVarBndrs to LHsQTyVars
      
      * There are some uninteresting knock-on changes in Haddock,
        because of the HsSyn changes
      
      I also did a bunch of loosely-related changes:
      
      * We already had type synonyms CoercionN/CoercionR for nominal and
        representational coercions.  I've added similar treatment for
      
            TcCoercionN/TcCoercionR
      
            mkWpCastN/mkWpCastN
      
        All just type synonyms but jolly useful.
      
      * I record-ised ForeignImport and ForeignExport
      
      * I improved the (poor) fix to Trac #10896, by making
        TcTyClsDecls.checkValidTyCl recover from errors, but adding a
        harmless, abstract TyCon to the envt if so.
      
      * I did some significant refactoring in RnEnv.lookupSubBndrOcc,
        for reasons that I have (embarrassingly) now totally forgotten.
        It had to do with something to do with import and export
      
      Updates haddock submodule.
      1e041b73
  12. 23 Nov, 2015 1 commit
  13. 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
  14. 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
  15. 17 Nov, 2015 1 commit
  16. 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
  17. 07 Nov, 2015 1 commit
  18. 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
  19. 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
  20. 16 Oct, 2015 1 commit
    • Adam Gundry's avatar
      Implement DuplicateRecordFields · b1884b0e
      Adam Gundry authored
      This implements DuplicateRecordFields, the first part of the
      OverloadedRecordFields extension, as described at
      https://ghc.haskell.org/trac/ghc/wiki/Records/OverloadedRecordFields/DuplicateRecordFields
      
      This includes fairly wide-ranging changes in order to allow multiple
      records within the same module to use the same field names.  Note that
      it does *not* allow record selector functions to be used if they are
      ambiguous, and it does not have any form of type-based disambiguation
      for selectors (but it does for updates). Subsequent parts will make
      overloading selectors possible using orthogonal extensions, as
      described on the wiki pages.  This part touches quite a lot of the
      codebase, and requires changes to several GHC API datatypes in order
      to distinguish between field labels (which may be overloaded) and
      selector function names (which are always unique).
      
      The Haddock submodule has been adapted to compile with the GHC API
      changes, but it will need further work to properly support modules
      that use the DuplicateRecordFields extension.
      
      Test Plan: New tests added in testsuite/tests/overloadedrecflds; these
      will be extended once the other parts are implemented.
      
      Reviewers: goldfire, bgamari, simonpj, austin
      
      Subscribers: sjcjoosten, haggholm, mpickering, bgamari, tibbe, thomie,
      goldfire
      
      Differential Revision: https://phabricator.haskell.org/D761
      b1884b0e
  21. 15 Oct, 2015 1 commit
  22. 17 Sep, 2015 1 commit
  23. 26 Jun, 2015 1 commit
    • Simon Peyton Jones's avatar
      Treat out-of-scope variables as holes · fb7b6922
      Simon Peyton Jones authored
      This patch implements the idea in Trac #10569.
      
      * An out-of-scope variable is treated as a typed expression
        hole.
      
      * That is, we don't report it in the type checker, not the
        renamer, and we when we do report it, we give its type.
      
      * Moreover, we can defer the error to runtime with
        -fdefer-typed-holes
      
      In implementation terms:
      
      * The renamer turns an unbound variable into a HsUnboundVar
      
      * The type checker emits a Hole constraint for a
        HsUnboundVar, and turns it back into a HsVar
      
      It was a bit painful to implement because a whole raft of
      error messages change slightly.  But there was absolutely
      nothing hard in principle.
      
      Holes are reported with a bunch of possibly-useful context,
      notably the "relevant bindings".  I found that this was
      distracting clutter in the very common case of a mis-typed
      variable that is only accidentally not in scope, so I've
      arranged to print the context information only for true holes,
      that is ones starting with an underscore.
      
      Unbound data constructors use in patterns, like
        f (D x) = x
      are still reportd by the renamer, and abort compilation
      before type checking.
      fb7b6922
  24. 06 May, 2015 2 commits
  25. 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
  26. 16 Dec, 2014 2 commits
    • Peter Wortmann's avatar
      Generalized Coverage pass to allow adding multiple types of Tickishs · 3b893f38
      Peter Wortmann authored
      This allows having, say, HPC ticks, automatic cost centres and source
      notes active at the same time. We especially take care to un-tangle the
      infrastructure involved in generating them.
      
      (From Phabricator D169)
      3b893f38
    • Peter Wortmann's avatar
      Source notes (Core support) · 993975d3
      Peter Wortmann authored
      This patch introduces "SourceNote" tickishs that link Core to the
      source code that generated it. The idea is to retain these source code
      links throughout code transformations so we can eventually relate
      object code all the way back to the original source (which we can,
      say, encode as DWARF information to allow debugging).  We generate
      these SourceNotes like other tickshs in the desugaring phase. The
      activating command line flag is "-g", consistent with the flag other
      compilers use to decide DWARF generation.
      
      Keeping ticks from getting into the way of Core transformations is
      tricky, but doable. The changes in this patch produce identical Core
      in all cases I tested -- which at this point is GHC, all libraries and
      nofib. Also note that this pass creates *lots* of tick nodes, which we
      reduce somewhat by removing duplicated and overlapping source
      ticks. This will still cause significant Tick "clumps" - a possible
      future optimization could be to make Tick carry a list of Tickishs
      instead of one at a time.
      
      (From Phabricator D169)
      993975d3
  27. 10 Dec, 2014 1 commit
  28. 03 Dec, 2014 1 commit
  29. 28 Nov, 2014 1 commit
    • Simon Peyton Jones's avatar
      Rename some of the functions in NameSet, to make the uniform with VarSet etc · 7460dafa
      Simon Peyton Jones authored
      For ages NameSet has used different names,
        eg.   addOneToNameSet   rather than    extendNameSet
              nameSetToList     rather than    nameSetElems
      
      etc.  Other set-like modules use uniform naming conventions.
      This patch makes NameSet follow suit.
      
      No change in behaviour; this is just renaming.
      
      I'm doing this just before the fork so that merging is easier.
      7460dafa
  30. 21 Nov, 2014 1 commit
  31. 09 Sep, 2014 1 commit
    • Austin Seipp's avatar
      Make Applicative a superclass of Monad · d94de872
      Austin Seipp authored
      Summary:
      This includes pretty much all the changes needed to make `Applicative`
      a superclass of `Monad` finally. There's mostly reshuffling in the
      interests of avoid orphans and boot files, but luckily we can resolve
      all of them, pretty much. The only catch was that
      Alternative/MonadPlus also had to go into Prelude to avoid this.
      
      As a result, we must update the hsc2hs and haddock submodules.
      Signed-off-by: default avatarAustin Seipp <austin@well-typed.com>
      
      Test Plan: Build things, they might not explode horribly.
      
      Reviewers: hvr, simonmar
      
      Subscribers: simonmar
      
      Differential Revision: https://phabricator.haskell.org/D13
      d94de872
  32. 21 Jul, 2014 1 commit
    • Edward Z. Yang's avatar
      Rename PackageId to PackageKey, distinguishing it from Cabal's PackageId. · 4bebab25
      Edward Z. Yang authored
      Summary:
      Previously, both Cabal and GHC defined the type PackageId, and we expected
      them to be roughly equivalent (but represented differently).  This refactoring
      separates these two notions.
      
      A package ID is a user-visible identifier; it's the thing you write in a
      Cabal file, e.g. containers-0.9.  The components of this ID are semantically
      meaningful, and decompose into a package name and a package vrsion.
      
      A package key is an opaque identifier used by GHC to generate linking symbols.
      Presently, it just consists of a package name and a package version, but
      pursuant to #9265 we are planning to extend it to record other information.
      Within a single executable, it uniquely identifies a package.  It is *not* an
      InstalledPackageId, as the choice of a package key affects the ABI of a package
      (whereas an InstalledPackageId is computed after compilation.)  Cabal computes
      a package key for the package and passes it to GHC using -package-name (now
      *extremely* misnamed).
      
      As an added bonus, we don't have to worry about shadowing anymore.
      
      As a follow on, we should introduce -current-package-key having the same role as
      -package-name, and deprecate the old flag.  This commit is just renaming.
      
      The haddock submodule needed to be updated.
      Signed-off-by: default avatarEdward Z. Yang <ezyang@cs.stanford.edu>
      
      Test Plan: validate
      
      Reviewers: simonpj, simonmar, hvr, austin
      
      Subscribers: simonmar, relrod, carter
      
      Differential Revision: https://phabricator.haskell.org/D79
      
      Conflicts:
      	compiler/main/HscTypes.lhs
      	compiler/main/Packages.lhs
      	utils/haddock
      4bebab25
  33. 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.
      23892440
  34. 13 Apr, 2014 1 commit
  35. 20 Jan, 2014 1 commit
    • cactus's avatar
      Implement pattern synonyms · 4f8369bf
      cactus 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/ImplementationReviewed-by: Simon Peyton Jones's avatarSimon Peyton Jones <simonpj@microsoft.com>
      Signed-off-by: default avatarAustin Seipp <austin@well-typed.com>
      4f8369bf
  36. 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
  37. 11 Sep, 2013 1 commit