1. 19 Apr, 2011 1 commit
  2. 02 Apr, 2011 1 commit
  3. 22 Dec, 2010 1 commit
    • simonpj@microsoft.com's avatar
      Tidy up rebindable syntax for MDo · ba05282d
      simonpj@microsoft.com authored
      For a long time an 'mdo' expression has had a SyntaxTable
      attached to it.  However, we're busy deprecating SyntaxTables
      in favour of rebindable syntax attached to individual Stmts,
      and MDoExpr was totally inconsistent with DoExpr in this
      regard.
      
      This patch tidies it all up.  Now there's no SyntaxTable on
      MDoExpr, and 'modo' is generally handled much more like 'do'.
      
      There is resulting small change in behaviour: now MonadFix is
      required only if you actually *use* recursion in mdo. This
      seems consistent with the implicit dependency analysis that
      is done for mdo.
      
      Still to do:
        * Deal with #4148 (this patch is on the way)
        * Get rid of the last remaining SyntaxTable on HsCmdTop
      ba05282d
  4. 07 Oct, 2010 1 commit
    • simonpj@microsoft.com's avatar
      Implement auto-specialisation of imported Ids · 92267aa2
      simonpj@microsoft.com authored
      This big-ish patch arranges that if an Id 'f' is 
        * Type-class overloaded 
             f :: Ord a => [a] -> [a]
        * Defined with an INLINABLE pragma
             {-# INLINABLE f #-}
        * Exported from its defining module 'D'
      
      then in any module 'U' that imports D
      
      1. Any call of 'f' at a fixed type will generate 
         (a) a specialised version of f in U
         (b) a RULE that rewrites unspecialised calls to the
             specialised on
      
        e.g. if the call is (f Int dOrdInt xs) then the 
        specialiser will generate
           $sfInt :: [Int] -> [Int]
           $sfInt = <code for f, imported from D, specialised>
           {-# RULE forall d.  f Int d = $sfInt #-}
      
      2. In addition, you can give an explicit {-# SPECIALISE -#}
         pragma for the imported Id
           {-# SPECIALISE f :: [Bool] -> [Bool] #-}
         This too generates a local specialised definition, 
         and the corresponding RULE 
      
      The new RULES are exported from module 'U', so that any module
      importing U will see the specialised versions of 'f', and will
      not re-specialise them.
      
      There's a flag -fwarn-auto-orphan that warns you if the auto-generated
      RULES are orphan rules. It's not in -Wall, mainly to avoid lots of
      error messages with existing packages.
      
      Main implementation changes
      
       - A new flag on a CoreRule to say if it was auto-generated.
         This is persisted across interface files, so there's a small
         change in interface file format.
      
       - Quite a bit of fiddling with plumbing, to get the 
         {-# SPECIALISE #-} pragmas for imported Ids.  In particular, a
         new field tgc_imp_specs in TcGblEnv, to keep the specialise
         pragmas for imported Ids between the typechecker and the desugarer.
      
       - Some new code (although surprisingly little) in Specialise,
         to deal with calls of imported Ids
      92267aa2
  5. 18 Sep, 2010 1 commit
  6. 13 Sep, 2010 1 commit
  7. 24 Jul, 2010 1 commit
  8. 14 Jun, 2010 1 commit
  9. 25 May, 2010 1 commit
    • simonpj@microsoft.com's avatar
      Refactor (again) the handling of default methods · 78693246
      simonpj@microsoft.com authored
      This patch fixes Trac #4056, by 
      
       a) tidying up the treatment of default method names
       b) removing the 'module' argument to newTopSrcBinder
      
      The details aren't that interesting, but the result
      is much tidier. The original bug was a 'nameModule' panic,
      caused by trying to find the module of a top-level name.
      But TH quotes generate Internal top-level names that don't
      have a module, and that is generally a good thing.  
      
      Fixing that in turn led to the default-method refactoring,
      which also makes the Name for a default method be handled
      in the same way as other derived names, generated in BuildTyCl
      via a call newImplicitBinder.  Hurrah.
      78693246
  10. 06 May, 2010 1 commit
    • simonpj@microsoft.com's avatar
      Make tcg_dus behave more sanely; fixes a mkUsageInfo panic · b2d9ef84
      simonpj@microsoft.com authored
      The tcg_dus field used to contain *uses* of type and class decls,
      but not *defs*.  That was inconsistent, and it really went wrong
      for Template Haskell bracket.  What happened was that
       foo = [d| data A = A
             	   f :: A -> A
             	   f x = x |]
      would find a "use" of A when processing the top level of the module,
      which in turn led to a mkUsageInfo panic in MkIface.  The cause was
      the fact that the tcg_dus for the nested quote didn't have defs for
      A.
      b2d9ef84
  11. 12 Apr, 2010 1 commit
  12. 04 Mar, 2010 1 commit
    • simonpj@microsoft.com's avatar
      Refactor part of the renamer to fix Trac #3901 · f1cc3eb9
      simonpj@microsoft.com authored
      This one was bigger than I anticipated!  The problem was that were
      were gathering the binders from a pattern before renaming -- but with
      record wild-cards we don't know what variables are bound by C {..}
      until after the renamer has filled in the "..".
      
      So this patch does the following
      
      * Change all the collect-X-Binders functions in HsUtils so that
        they expect to only be called *after* renaming.  That means they
        don't need to return [Located id] but just [id].  Which turned out
        to be a very worthwhile simplification all by itself.
      
      * Refactor the renamer, and in ptic RnExpr.rnStmt, so that it
        doesn't need to use collectLStmtsBinders on pre-renamed Stmts.
      
      * This in turn required me to understand how GroupStmt and
        TransformStmts were renamed.  Quite fiddly. I rewrote most of it;
        result is much shorter.
      
      * In doing so I flattened HsExpr.GroupByClause into its parent
        GroupStmt, with trivial knock-on effects in other files.
      
      Blargh.
      f1cc3eb9
  13. 07 Jan, 2010 1 commit
  14. 05 Nov, 2009 1 commit
    • simonpj@microsoft.com's avatar
      Fix Trac #3640, plus associated refactoring · df8b00e0
      simonpj@microsoft.com authored
      In fixing this bug (to do with record puns), I had the usual rush of
      blood to the head, and I did quite a bit of refactoring in the way
      that duplicate/shadowed names are reported.
      
      I think the result is shorter as well as clearer.
      
      In one place I found it convenient for the renamer to use the ErrCtxt
      carried in the monad.  (The renamer used not to have such a context,
      but years ago the typechecker and renamer monads became one, so now it
      does.)   So now it's availble if you want it in future.
      df8b00e0
  15. 20 Aug, 2009 2 commits
    • simonpj@microsoft.com's avatar
      Wibble to RnPat refactoring · 18b8ff4f
      simonpj@microsoft.com authored
      18b8ff4f
    • simonpj@microsoft.com's avatar
      Improvements to record puns, wildcards · d64022dc
      simonpj@microsoft.com authored
      * Make C { A.a } work with punning, expanding to C { A.a = a }
      
      * Make it so that, with -fwarn-unused-matches, 
              f (C {..}) = x
        does not complain about the bindings introduced by the "..".
      
      * Make -XRecordWildCards implies -XDisambiguateRecordFields.
      
      * Overall refactoring of RnPat, which had become very crufty. 
        In particular, there is now a monad, CpsRn, private to RnPat,
        which deals with the cps-style plumbing.  This is why so many
        lines of RnPat have changed.
      
      * Refactor the treatment of renaming of record fields into two passes
      	- rnHsRecFields1, used both for patterns and expressions,
      	     which expands puns, wild-cards
        	- a local renamer in RnPat for fields in patterns
      	- a local renamer in RnExpr for fields in construction and update
        This make it all MUCH easier to understand
       
      * Improve documentation of record puns, wildcards, and disambiguation
      d64022dc
  16. 24 Jul, 2009 1 commit
  17. 02 Jan, 2009 1 commit
    • simonpj@microsoft.com's avatar
      Make record selectors into ordinary functions · 9ffadf21
      simonpj@microsoft.com authored
      This biggish patch addresses Trac #2670.  The main effect is to make
      record selectors into ordinary functions, whose unfoldings appear in
      interface files, in contrast to their previous existence as magic
      "implicit Ids".  This means that the usual machinery of optimisation,
      analysis, and inlining applies to them, which was failing before when
      the selector was somewhat complicated.  (Which it can be when
      strictness annotations, unboxing annotations, and GADTs are involved.)
      
      The change involves the following points
      
      * Changes in Var.lhs to the representation of Var.  Now a LocalId can
        have an IdDetails as well as a GlobalId.  In particular, the
        information that an Id is a record selector is kept in the
        IdDetails.  While compiling the current module, the record selector
        *must* be a LocalId, so that it participates properly in compilation
        (free variables etc).
      
        This led me to change the (hidden) representation of Var, so that there
        is now only one constructor for Id, not two.
      
      * The IdDetails is persisted into interface files, so that an
        importing module can see which Ids are records selectors.
      
      * In TcTyClDecls, we generate the record-selector bindings in renamed,
        but not typechecked form.  In this way, we can get the typechecker
        to add all the types and so on, which is jolly helpful especially
        when GADTs or type families are involved.  Just like derived
        instance declarations.
      
        This is the big new chunk of 180 lines of code (much of which is
        commentary).  A call to the same function, mkAuxBinds, is needed in
        TcInstDcls for associated types.
      
      * The typechecker therefore has to pin the correct IdDetails on to 
        the record selector, when it typechecks it.  There was a neat way
        to do this, by adding a new sort of signature to HsBinds.Sig, namely
        IdSig.  This contains an Id (with the correct Name, Type, and IdDetails);
        the type checker uses it as the binder for the final binding.  This
        worked out rather easily.
      
      * Record selectors are no longer "implicit ids", which entails changes to
           IfaceSyn.ifaceDeclSubBndrs
           HscTypes.implicitTyThings
           TidyPgm.getImplicitBinds
        (These three functions must agree.)
      
      * MkId.mkRecordSelectorId is deleted entirely, some 300+ lines (incl
        comments) of very error prone code.  Happy days.
      
      * A TyCon no longer contains the list of record selectors: 
        algTcSelIds is gone
      
      The renamer is unaffected, including the way that import and export of
      record selectors is handled.
      
      Other small things
      
      * IfaceSyn.ifaceDeclSubBndrs had a fragile test for whether a data
        constructor had a wrapper.  I've replaced that with an explicit flag
        in the interface file. More robust I hope.
      
      * I renamed isIdVar to isId, which touched a few otherwise-unrelated files.
      
      9ffadf21
  18. 27 Oct, 2008 1 commit
  19. 03 Oct, 2008 2 commits
    • simonpj@microsoft.com's avatar
      Fix warnings · 7129b3c1
      simonpj@microsoft.com authored
      7129b3c1
    • simonpj@microsoft.com's avatar
      Expunge ThFake, cure Trac #2632 · 08a9d734
      simonpj@microsoft.com authored
      This patch fixes a dirty hack (the fake ThFake module), which in turn
      was causing Trac #2632.
      
      The new scheme is that the top-level binders in a TH [d| ... |] decl splice
      get Internal names.  That breaks a previous invariant that things like
      TyCons always have External names, but these TyCons are never long-lived;
      they live only long enough to typecheck the TH quotation; the result is
      discarded.  So it seems cool.
      
      Nevertheless -- Template Haskell folk: please test your code.  The testsuite
      is OK but it's conceivable that I've broken something in TH.  Let's see.
      08a9d734
  20. 04 Sep, 2008 1 commit
  21. 30 Aug, 2008 2 commits
  22. 11 Aug, 2008 1 commit
  23. 31 Jul, 2008 1 commit
  24. 20 Jul, 2008 1 commit
  25. 04 Jun, 2008 1 commit
  26. 20 May, 2008 1 commit
  27. 03 May, 2008 1 commit
  28. 12 Apr, 2008 1 commit
  29. 10 Apr, 2008 1 commit
  30. 04 Apr, 2008 1 commit
    • simonpj@microsoft.com's avatar
      Fix Trac #2188: scoping in TH declarations quotes · a27c5f77
      simonpj@microsoft.com authored
      This patch fixes a rather tiresome issue, namely the fact that
      a TH declaration quote *shadows* bindings in outer scopes:
      
        f g = [d| f :: Int
                  f = g
        	    g :: Int
                  g = 4 |]
      
      Here, the outer bindings for 'f' (top-level) and 'g' (local)
      are shadowed, and the inner bindings for f,g should not be
      reported as duplicates.  (Remember they are top-level bindings.)
      
      The actual bug was that we'd forgotten to delete 'g' from the
      LocalRdrEnv, so the type sig for 'g' was binding to the outer
      'g' not the inner one.
      a27c5f77
  31. 03 Apr, 2008 1 commit
    • simonpj@microsoft.com's avatar
      Fix Trac #2136: reporting of unused variables · 7502efdc
      simonpj@microsoft.com authored
      There's a bit of a hack RnBinds.rnValBindsAndThen, documented
      in Note [Unused binding hack].  But the hack was over brutal
      before, and produced unnecssarily bad (absence of) warnings.
      This patch does a bit of refactoring; and fixes the bug in
      rnValBindsAndThen.
      7502efdc
  32. 29 Mar, 2008 1 commit
  33. 07 Feb, 2008 1 commit
    • Ian Lynagh's avatar
      Convert more UniqFM's back to LazyUniqFM's · d51f42f6
      Ian Lynagh authored
      These fix these failures:
         break008(ghci)
         break009(ghci)
         break026(ghci)
         ghci.prog009(ghci)
         ghci025(ghci)
         print007(ghci)
         prog001(ghci)
         prog002(ghci)
         prog003(ghci)
      at least some of which have this symptom:
          Exception: expectJust prune
      d51f42f6
  34. 17 Jan, 2008 1 commit
  35. 18 Jan, 2008 1 commit
    • simonpj@microsoft.com's avatar
      Add quasi-quotation, courtesy of Geoffrey Mainland · f3399c44
      simonpj@microsoft.com authored
      This patch adds quasi-quotation, as described in
        "Nice to be Quoted: Quasiquoting for Haskell"
      	(Geoffrey Mainland, Haskell Workshop 2007)
      Implemented by Geoffrey and polished by Simon.
      
      Overview
      ~~~~~~~~
      The syntax for quasiquotation is very similar to the existing
      Template haskell syntax:
      	[$q| stuff |]
      where 'q' is the "quoter".  This syntax differs from the paper, by using
      a '$' rather than ':', to avoid clashing with parallel array comprehensions.
       
      The "quoter" is a value of type Language.Haskell.TH.Quote.QuasiQuoter, which
      contains two functions for quoting expressions and patterns, respectively.
       
           quote = Language.Haskell.TH.Quote.QuasiQuoter quoteExp quotePat
       
           quoteExp :: String -> Language.Haskell.TH.ExpQ
           quotePat :: String -> Language.Haskell.TH.PatQ
      
      TEXT is passed unmodified to the quoter. The context of the
      quasiquotation statement determines which of the two quoters is
      called: if the quasiquotation occurs in an expression context,
      quoteExp is called, and if it occurs in a pattern context, quotePat
      is called.
      
      The result of running the quoter on its arguments is spliced into
      the program using Template Haskell's existing mechanisms for
      splicing in code. Note that although Template Haskell does not
      support pattern brackets, with this patch binding occurrences of
      variables in patterns are supported. Quoters must also obey the same
      stage restrictions as Template Haskell; in particular, in this
      example quote may not be defined in the module where it is used as a
      quasiquoter, but must be imported from another module.
      
      Points to notice
      ~~~~~~~~~~~~~~~~
      * The whole thing is enabled with the flag -XQuasiQuotes
      
      * There is an accompanying patch to the template-haskell library. This
        involves one interface change:
      	currentModule :: Q String
        is replaced by
      	location :: Q Loc
        where Loc is a data type defined in TH.Syntax thus:
            data Loc
              = Loc { loc_filename :: String
      	      , loc_package  :: String
      	      , loc_module   :: String
      	      , loc_start    :: CharPos
      	      , loc_end      :: CharPos }
      
            type CharPos = (Int, Int)	-- Line and character position
       
        So you get a lot more info from 'location' than from 'currentModule'.
        The location you get is the location of the splice.
        
        This works in Template Haskell too of course, and lets a TH program
        generate much better error messages.
      
      * There's also a new module in the template-haskell package called 
        Language.Haskell.TH.Quote, which contains support code for the
        quasi-quoting feature.
      
      * Quasi-quote splices are run *in the renamer* because they can build 
        *patterns* and hence the renamer needs to see the output of running the
        splice.  This involved a bit of rejigging in the renamer, especially
        concerning the reporting of duplicate or shadowed names.
      
        (In fact I found and removed a few calls to checkDupNames in RnSource 
        that are redundant, becuase top-level duplicate decls are handled in
        RnNames.)
      
      
      f3399c44
  36. 13 Dec, 2007 1 commit
    • simonpj@microsoft.com's avatar
      Improve free-variable handling for rnPat and friends (fixes Trac #1972) · 7f2909e0
      simonpj@microsoft.com authored
      As well as fixing the immediate problem (Trac #1972) this patch does
      a signficant simplification and refactoring of pattern renaming.
      
      Fewer functions, fewer parameters passed....it's all good.  But it
      took much longer than I expected to figure out.
      
      The most significant change is that the NameMaker type does *binding*
      as well as *making* and, in the matchNameMaker case, checks for unused
      bindings as well.  This is much tider.
      
      (No need to merge to the 6.8 branch, but no harm either.)
      
      7f2909e0
  37. 10 Oct, 2007 1 commit
    • Dan Licata's avatar
      View patterns, record wildcards, and record puns · 6a05ec5e
      Dan Licata authored
      This patch implements three new features:
      * view patterns (syntax: expression -> pat in a pattern)
      * working versions of record wildcards and record puns
      See the manual for detailed descriptions.
      
      Other minor observable changes:
      * There is a check prohibiting local fixity declarations
        when the variable being fixed is not defined in the same let
      * The warn-unused-binds option now reports warnings for do and mdo stmts
      
      Implementation notes: 
      
      * The pattern renamer is now in its own module, RnPat, and the
      implementation is now in a CPS style so that the correct context is
      delivered to pattern expressions.
      
      * These features required a fairly major upheaval to the renamer.
      Whereas the old version used to collect up all the bindings from a let
      (or top-level, or recursive do statement, ...) and put them into scope
      before renaming anything, the new version does the collection as it
      renames.  This allows us to do the right thing with record wildcard
      patterns (which need to be expanded to see what names should be
      collected), and it allows us to implement the desired semantics for view
      patterns in lets.  This change had a bunch of domino effects brought on
      by fiddling with the top-level renaming.
      
      * Prior to this patch, there was a tricky bug in mkRecordSelId in HEAD,
      which did not maintain the invariant necessary for loadDecl.  See note
      [Tricky iface loop] for details.
      6a05ec5e