1. 02 Aug, 2013 1 commit
  2. 06 Apr, 2013 1 commit
  3. 22 Dec, 2012 1 commit
    • eir@cis.upenn.edu's avatar
      Implement overlapping type family instances. · 8366792e
      eir@cis.upenn.edu authored
      An ordered, overlapping type family instance is introduced by 'type
      instance
      where', followed by equations. See the new section in the user manual
      (7.7.2.2) for details. The canonical example is Boolean equality at the
      type
      level:
      
      type family Equals (a :: k) (b :: k) :: Bool
      type instance where
        Equals a a = True
        Equals a b = False
      
      A branched family instance, such as this one, checks its equations in
      order
      and applies only the first the matches. As explained in the note
      [Instance
      checking within groups] in FamInstEnv.lhs, we must be careful not to
      simplify,
      say, (Equals Int b) to False, because b might later unify with Int.
      
      This commit includes all of the commits on the overlapping-tyfams
      branch. SPJ
      requested that I combine all my commits over the past several months
      into one
      monolithic commit. The following GHC repos are affected: ghc, testsuite,
      utils/haddock, libraries/template-haskell, and libraries/dph.
      
      Here are some details for the interested:
      
      - The definition of CoAxiom has been moved from TyCon.lhs to a
        new file CoAxiom.lhs. I made this decision because of the
        number of definitions necessary to support BranchList.
      
      - BranchList is a GADT whose type tracks whether it is a
        singleton list or not-necessarily-a-singleton-list. The reason
        I introduced this type is to increase static checking of places
        where GHC code assumes that a FamInst or CoAxiom is indeed a
        singleton. This assumption takes place roughly 10 times
        throughout the code. I was worried that a future change to GHC
        would invalidate the assumption, and GHC might subtly fail to
        do the right thing. By explicitly labeling CoAxioms and
        FamInsts as being Unbranched (singleton) or
        Branched (not-necessarily-singleton), we make this assumption
        explicit and checkable. Furthermore, to enforce the accuracy of
        this label, the list of branches of a CoAxiom or FamInst is
        stored using a BranchList, whose constructors constrain its
        type index appropriately.
      
      I think that the decision to use BranchList is probably the most
      controversial decision I made from a code design point of view.
      Although I provide conversions to/from ordinary lists, it is more
      efficient to use the brList... functions provided in CoAxiom than
      always to convert. The use of these functions does not wander far
      from the core CoAxiom/FamInst logic.
      
      BranchLists are motivated and explained in the note [Branched axioms] in
      CoAxiom.lhs.
      
      - The CoAxiom type has changed significantly. You can see the new
        type in CoAxiom.lhs. It uses a CoAxBranch type to track
        branches of the CoAxiom. Correspondingly various functions
        producing and consuming CoAxioms had to change, including the
        binary layout of interface files.
      
      - To get branched axioms to work correctly, it is important to have a
        notion
        of type "apartness": two types are apart if they cannot unify, and no
        substitution of variables can ever get them to unify, even after type
      family
        simplification. (This is different than the normal failure to unify
      because
        of the type family bit.) This notion in encoded in tcApartTys, in
      Unify.lhs.
        Because apartness is finer-grained than unification, the tcUnifyTys
      now
        calls tcApartTys.
      
      - CoreLinting axioms has been updated, both to reflect the new
        form of CoAxiom and to enforce the apartness rules of branch
        application. The formalization of the new rules is in
        docs/core-spec/core-spec.pdf.
      
      - The FamInst type (in types/FamInstEnv.lhs) has changed
        significantly, paralleling the changes to CoAxiom. Of course,
        this forced minor changes in many files.
      
      - There are several new Notes in FamInstEnv.lhs, including one
        discussing confluent overlap and why we're not doing it.
      
      - lookupFamInstEnv, lookupFamInstEnvConflicts, and
        lookup_fam_inst_env' (the function that actually does the work)
        have all been more-or-less completely rewritten. There is a
        Note [lookup_fam_inst_env' implementation] describing the
        implementation. One of the changes that affects other files is
        to change the type of matches from a pair of (FamInst, [Type])
        to a new datatype (which now includes the index of the matching
        branch). This seemed a better design.
      
      - The TySynInstD constructor in Template Haskell was updated to
        use the new datatype TySynEqn. I also bumped the TH version
        number, requiring changes to DPH cabal files. (That's why the
        DPH repo has an overlapping-tyfams branch.)
      
      - As SPJ requested, I refactored some of the code in HsDecls:
      
       * splitting up TyDecl into SynDecl and DataDecl, correspondingly
         changing HsTyDefn to HsDataDefn (with only one constructor)
      
       * splitting FamInstD into TyFamInstD and DataFamInstD and
         splitting FamInstDecl into DataFamInstDecl and TyFamInstDecl
      
       * making the ClsInstD take a ClsInstDecl, for parallelism with
         InstDecl's other constructors
      
       * changing constructor TyFamily into FamDecl
      
       * creating a FamilyDecl type that stores the details for a family
         declaration; this is useful because FamilyDecls can appear in classes
      but
         other decls cannot
      
       * restricting the associated types and associated type defaults for a
       * class
         to be the new, more restrictive types
      
       * splitting cid_fam_insts into cid_tyfam_insts and cid_datafam_insts,
         according to the new types
      
       * perhaps one or two more that I'm overlooking
      
      None of these changes has far-reaching implications.
      
      - The user manual, section 7.7.2.2, is updated to describe the new type
        family
        instances.
      8366792e
  4. 17 Sep, 2012 1 commit
    • Simon Peyton Jones's avatar
      Implement 'left' and 'right' coercions · af7cc995
      Simon Peyton Jones authored
      This patch finally adds 'left' and 'right' coercions back into
      GHC.  Trac #7205 gives the details.
      
      The main change is to add a new constructor to Coercion:
      
        data Coercion
          = ...
          | NthCo  Int         Coercion     -- OLD, still there
          | LRCo   LeftOrRight Coercion     -- NEW
      
        data LeftOrRight = CLeft | CRight
      
      Plus:
        * Similar change to TcCoercion
        * Use LRCo when decomposing AppTys
        * Coercion optimisation needs to handle left/right
      
      The rest is just knock-on effects.
      af7cc995
  5. 14 Jul, 2012 1 commit
    • Ian Lynagh's avatar
      Implement FastBytes, and use it for MachStr · 7ae1bec5
      Ian Lynagh authored
      This is a first step on the way to refactoring the FastString type.
      
      FastBytes currently has no unique, mainly because there isn't currently
      a nice way to produce them in Binary.
      
      Also, we don't currently do the "Dictionary" thing with FastBytes in
      Binary. I'm not sure whether this is important.
      
      We can change both decisions later, but in the meantime this gets the
      refactoring underway.
      7ae1bec5
  6. 04 Nov, 2011 1 commit
  7. 02 Nov, 2011 1 commit
    • Simon Marlow's avatar
      Overhaul of infrastructure for profiling, coverage (HPC) and breakpoints · 7bb0447d
      Simon Marlow authored
      User visible changes
      ====================
      
      Profilng
      --------
      
      Flags renamed (the old ones are still accepted for now):
      
        OLD            NEW
        ---------      ------------
        -auto-all      -fprof-auto
        -auto          -fprof-exported
        -caf-all       -fprof-cafs
      
      New flags:
      
        -fprof-auto              Annotates all bindings (not just top-level
                                 ones) with SCCs
      
        -fprof-top               Annotates just top-level bindings with SCCs
      
        -fprof-exported          Annotates just exported bindings with SCCs
      
        -fprof-no-count-entries  Do not maintain entry counts when profiling
                                 (can make profiled code go faster; useful with
                                 heap profiling where entry counts are not used)
      
      Cost-centre stacks have a new semantics, which should in most cases
      result in more useful and intuitive profiles.  If you find this not to
      be the case, please let me know.  This is the area where I have been
      experimenting most, and the current solution is probably not the
      final version, however it does address all the outstanding bugs and
      seems to be better than GHC 7.2.
      
      Stack traces
      ------------
      
      +RTS -xc now gives more information.  If the exception originates from
      a CAF (as is common, because GHC tends to lift exceptions out to the
      top-level), then the RTS walks up the stack and reports the stack in
      the enclosing update frame(s).
      
      Result: +RTS -xc is much more useful now - but you still have to
      compile for profiling to get it.  I've played around a little with
      adding 'head []' to GHC itself, and +RTS -xc does pinpoint the problem
      quite accurately.
      
      I plan to add more facilities for stack tracing (e.g. in GHCi) in the
      future.
      
      Coverage (HPC)
      --------------
      
       * derived instances are now coloured yellow if they weren't used
       * likewise record field names
       * entry counts are more accurate (hpc --fun-entry-count)
       * tab width is now correct (markup was previously off in source with
         tabs)
      
      Internal changes
      ================
      
      In Core, the Note constructor has been replaced by
      
              Tick (Tickish b) (Expr b)
      
      which is used to represent all the kinds of source annotation we
      support: profiling SCCs, HPC ticks, and GHCi breakpoints.
      
      Depending on the properties of the Tickish, different transformations
      apply to Tick.  See CoreUtils.mkTick for details.
      
      Tickets
      =======
      
      This commit closes the following tickets, test cases to follow:
      
        - Close #2552: not a bug, but the behaviour is now more intuitive
          (test is T2552)
      
        - Close #680 (test is T680)
      
        - Close #1531 (test is result001)
      
        - Close #949 (test is T949)
      
        - Close #2466: test case has bitrotted (doesn't compile against current
          version of vector-space package)
      7bb0447d
  8. 06 Sep, 2011 1 commit
  9. 19 Apr, 2011 1 commit
    • Simon Peyton Jones's avatar
      This BIG PATCH contains most of the work for the New Coercion Representation · fdf86568
      Simon Peyton Jones authored
      See the paper "Practical aspects of evidence based compilation in System FC"
      
      * Coercion becomes a data type, distinct from Type
      
      * Coercions become value-level things, rather than type-level things,
        (although the value is zero bits wide, like the State token)
        A consequence is that a coerion abstraction increases the arity by 1
        (just like a dictionary abstraction)
      
      * There is a new constructor in CoreExpr, namely Coercion, to inject
        coercions into terms
      fdf86568
  10. 16 Jan, 2011 1 commit
    • Iavor S. Diatchki's avatar
      Add basic support for number type literals. · 9cbc204d
      Iavor S. Diatchki authored
      We add a new kind, Nat, inhabited by a family of types,
      one for each natural number:
      
      0, 1, 2 .. :: Nat
      
      In terms of GHC's sub-kind relation, Nat is only a sub-kind of itself.
      
      The numeric types are empty because there are no primitives of these
      types, and the kind "Nat" is not related to *, the kind of types which
      can be defined in Haskell programs.
      9cbc204d
  11. 04 May, 2008 2 commits
  12. 22 Apr, 2008 1 commit
  13. 10 Apr, 2008 1 commit
    • chevalier@alum.wellesley.edu's avatar
      Another round of External Core fixes · 4c6a3f78
      chevalier@alum.wellesley.edu authored
      With this patch, GHC should now be printing External Core in a format
      that a stand-alone program can parse and typecheck. Major bug fixes:
      
      - The printer now handles qualified/unqualified declarations correctly
         (particularly data constructor declarations)
      - It prints newtype declarations with enough information to
        typecheck code that uses the induced coercions (this required a
      syntax change)
      - It expands type synonyms correctly
       
      Documentation and external tool patches will follow.
      4c6a3f78
  14. 28 Mar, 2008 1 commit
  15. 25 Mar, 2008 1 commit
    • chevalier@alum.wellesley.edu's avatar
      Change syntax for newtypes in External Core · 2fbab1a0
      chevalier@alum.wellesley.edu authored
      The way that newtype declarations were printed in External Core files was
      incomplete, since there was no declaration for the coercion introduced by a
      newtype.
      
      For example, the Haskell source:
      
      newtype T a = MkT (a -> a)
      
      foo (MkT x) = x
      
      got printed out in External Core as (roughly):
      
        %newtype T a = a -> a;
      
        foo :: %forall t . T t -> t -> t =
          %cast (\ @ t -> a1 @ t)
          (%forall t . T t -> ZCCoT t);
      
      There is no declaration anywhere in the External Core program for :CoT, so
      that's bad.
      
      I changed the newtype decl syntax so as to include the declaration for the
      coercion axiom introduced by the newtype. Now, it looks like:
      
        %newtype T a ^ (ZCCoT :: ((T a) :=: (a -> a))) = a -> a;
      
      And an external typechecker could conceivably typecheck code that uses this.
      
      The major changes are to MkExternalCore and PprExternalCore (as well as
      ExternalCore, to change the External Core AST.) I also corrected some typos in
      comments in other files.
      
      Documentation and external tool changes to follow.
      2fbab1a0
  16. 24 Mar, 2008 2 commits
  17. 23 Mar, 2008 1 commit
  18. 26 Jan, 2008 1 commit
  19. 04 Sep, 2007 1 commit
  20. 03 Sep, 2007 1 commit
  21. 01 Sep, 2007 1 commit
  22. 13 Nov, 2006 1 commit
    • Aaron Tomb's avatar
      Fix external core syntax (though not full compilation) · de777ba4
      Aaron Tomb authored
      This patch updates the External Core creator, pretty-printer, and parser to
      agree on a concrete syntax for External Core, including the constructs
      required by the change to System FC. Code to create valid ASTs from External
      Core files will come later, as will bits for renaming, typechecking, and
      desugaring.
      de777ba4
  23. 01 Nov, 2006 1 commit
    • SamB's avatar
      Get External Core (-fext-core) working with readline · e513c1cc
      SamB authored
      Had to add support for dynamic C calls and for foreign labels (Addr#
      constants). Actually I only did the printing side -- parsing is not
      done yet. But at least now you can build the libraries with -fext-core.
      
      I also got the function arrow to print out properly again (it was
      printing fully-qualified and z-coded!)
      
      I also added a field for calling convention name to the External
      data constructor in ExternalCore.Exp (for static C calls).
      
      I'm not exactly sure where to document all of this, so I haven't done
      that, though I did comment the code a bit.
      e513c1cc
  24. 11 Oct, 2006 1 commit
    • Simon Marlow's avatar
      Module header tidyup, phase 1 · 49c98d14
      Simon Marlow authored
      This patch is a start on removing import lists and generally tidying
      up the top of each module.  In addition to removing import lists:
      
         - Change DATA.IOREF -> Data.IORef etc.
         - Change List -> Data.List etc.
         - Remove $Id$
         - Update copyrights
         - Re-order imports to put non-GHC imports last
         - Remove some unused and duplicate imports
      49c98d14
  25. 04 Aug, 2006 1 commit
  26. 02 Jul, 2006 1 commit
    • Jan Rochel's avatar
      Add %local-tag to external core output · 99bab7d8
      Jan Rochel authored
      Hello, this is my first patch contributed to GHC. If there are any
      inadequacies about it (maybe like this introductory disclaimer), please
      let me know about it.
      
      So, the need for this patch arose, while I was involved with processing
      hcr files (external core output) and I noticed, that the output didn't
      fully conform to the specification [1].
      No %local-tags were used, which turned out to be a real nuisance as it
      was not possible to determine which VDEFs can be erased in a further
      optimization process and which ones are exported by the module.
      
      Since the specification does not define the meaning of the %local-tag, I
      assume, it makes sense, that it tags all functions, that are not
      exported by the module.
      
      The patch does not fully comply to the specification, as in my
      implementation a local tag may appear before a VDEF but not before a
      VDEFG.
      
      [1] An External Representation for the GHC Core Language
          (DRAFT for GHC5.02), page 3, line 1
      
      Greetings
      Jan
      99bab7d8
  27. 23 Jun, 2006 1 commit
  28. 07 Apr, 2006 1 commit
    • Simon Marlow's avatar
      Reorganisation of the source tree · 0065d5ab
      Simon Marlow authored
      Most of the other users of the fptools build system have migrated to
      Cabal, and with the move to darcs we can now flatten the source tree
      without losing history, so here goes.
      
      The main change is that the ghc/ subdir is gone, and most of what it
      contained is now at the top level.  The build system now makes no
      pretense at being multi-project, it is just the GHC build system.
      
      No doubt this will break many things, and there will be a period of
      instability while we fix the dependencies.  A straightforward build
      should work, but I haven't yet fixed binary/source distributions.
      Changes to the Building Guide will follow, too.
      0065d5ab
  29. 30 Sep, 2004 1 commit
    • simonpj's avatar
      [project @ 2004-09-30 10:35:15 by simonpj] · 23f40f0e
      simonpj authored
      ------------------------------------
      	Add Generalised Algebraic Data Types
      	------------------------------------
      
      This rather big commit adds support for GADTs.  For example,
      
          data Term a where
       	  Lit :: Int -> Term Int
      	  App :: Term (a->b) -> Term a -> Term b
      	  If  :: Term Bool -> Term a -> Term a
      	  ..etc..
      
          eval :: Term a -> a
          eval (Lit i) = i
          eval (App a b) = eval a (eval b)
          eval (If p q r) | eval p    = eval q
          		    | otherwise = eval r
      
      
      Lots and lots of of related changes throughout the compiler to make
      this fit nicely.
      
      One important change, only loosely related to GADTs, is that skolem
      constants in the typechecker are genuinely immutable and constant, so
      we often get better error messages from the type checker.  See
      TcType.TcTyVarDetails.
      
      There's a new module types/Unify.lhs, which has purely-functional
      unification and matching for Type. This is used both in the typechecker
      (for type refinement of GADTs) and in Core Lint (also for type refinement).
      23f40f0e
  30. 09 Oct, 2003 1 commit
    • simonpj's avatar
      [project @ 2003-10-09 11:58:39 by simonpj] · 98688c6e
      simonpj authored
      -------------------------
      		GHC heart/lung transplant
      		-------------------------
      
      This major commit changes the way that GHC deals with importing
      types and functions defined in other modules, during renaming and
      typechecking.  On the way I've changed or cleaned up numerous other
      things, including many that I probably fail to mention here.
      
      Major benefit: GHC should suck in many fewer interface files when
      compiling (esp with -O).  (You can see this with -ddump-rn-stats.)
      
      It's also some 1500 lines of code shorter than before.
      
      **	So expect bugs!  I can do a 3-stage bootstrap, and run
      **	the test suite, but you may be doing stuff I havn't tested.
      ** 	Don't update if you are relying on a working HEAD.
      
      
      In particular, (a) External Core and (b) GHCi are very little tested.
      
      	But please, please DO test this version!
      
      
      	------------------------
      		Big things
      	------------------------
      
      Interface files, version control, and importing declarations
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      * There is a totally new data type for stuff that lives in interface files:
      	Original names			IfaceType.IfaceExtName
      	Types				IfaceType.IfaceType
      	Declarations (type,class,id)	IfaceSyn.IfaceDecl
      	Unfoldings			IfaceSyn.IfaceExpr
        (Previously we used HsSyn for type/class decls, and UfExpr for unfoldings.)
        The new data types are in iface/IfaceType and iface/IfaceSyn.  They are
        all instances of Binary, so they can be written into interface files.
        Previous engronkulation concering the binary instance of RdrName has
        gone away -- RdrName is not an instance of Binary any more.  Nor does
        Binary.lhs need to know about the ``current module'' which it used to,
        which made it specialised to GHC.
      
        A good feature of this is that the type checker for source code doesn't
        need to worry about the possibility that we might be typechecking interface
        file stuff.  Nor does it need to do renaming; we can typecheck direct from
        IfaceSyn, saving a whole pass (module TcIface)
      
      * Stuff from interface files is sucked in *lazily*, rather than being eagerly
        sucked in by the renamer. Instead, we use unsafeInterleaveIO to capture
        a thunk for the unfolding of an imported function (say).  If that unfolding
        is every pulled on, TcIface will scramble over the unfolding, which may
        in turn pull in the interface files of things mentioned in the unfolding.
      
        The External Package State is held in a mutable variable so that it
        can be side-effected by this lazy-sucking-in process (which may happen
        way later, e.g. when the simplifier runs).   In effect, the EPS is a kind
        of lazy memo table, filled in as we suck things in.  Or you could think
        of it as a global symbol table, populated on demand.
      
      * This lazy sucking is very cool, but it can lead to truly awful bugs. The
        intent is that updates to the symbol table happen atomically, but very bad
        things happen if you read the variable for the table, and then force a
        thunk which updates the table.  Updates can get lost that way. I regret
        this subtlety.
      
        One example of the way it showed up is that the top level of TidyPgm
        (which updates the global name cache) to be much more disciplined about
        those updates, since TidyPgm may itself force thunks which allocate new
        names.
      
      * Version numbering in interface files has changed completely, fixing
        one major bug with ghc --make.  Previously, the version of A.f changed
        only if A.f's type and unfolding was textually different.  That missed
        changes to things that A.f's unfolding mentions; which was fixed by
        eagerly sucking in all of those things, and listing them in the module's
        usage list.  But that didn't work with --make, because they might have
        been already sucked in.
      
        Now, A.f's version changes if anything reachable from A.f (via interface
        files) changes.  A module with unchanged source code needs recompiling
        only if the versions of any of its free variables changes. [This isn't
        quite right for dictionary functions and rules, which aren't mentioned
        explicitly in the source.  There are extensive comments in module MkIface,
        where all version-handling stuff is done.]
      
      * We don't need equality on HsDecls any more (because they aren't used in
        interface files).  Instead we have a specialised equality for IfaceSyn
        (eqIfDecl etc), which uses IfaceEq instead of Bool as its result type.
        See notes in IfaceSyn.
      
      * The horrid bit of the renamer that tried to predict what instance decls
        would be needed has gone entirely.  Instead, the type checker simply
        sucks in whatever instance decls it needs, when it needs them.  Easy!
      
        Similarly, no need for 'implicitModuleFVs' and 'implicitTemplateHaskellFVs'
        etc.  Hooray!
      
      
      Types and type checking
      ~~~~~~~~~~~~~~~~~~~~~~~
      * Kind-checking of types is far far tidier (new module TcHsTypes replaces
        the badly-named TcMonoType).  Strangely, this was one of my
        original goals, because the kind check for types is the Right Place to
        do type splicing, but it just didn't fit there before.
      
      * There's a new representation for newtypes in TypeRep.lhs.  Previously
        they were represented using "SourceTypes" which was a funny compromise.
        Now they have their own constructor in the Type datatype.  SourceType
        has turned back into PredType, which is what it used to be.
      
      * Instance decl overlap checking done lazily.  Consider
      	instance C Int b
      	instance C a Int
        These were rejected before as overlapping, because when seeking
        (C Int Int) one couldn't tell which to use.  But there's no problem when
        seeking (C Bool Int); it can only be the second.
      
        So instead of checking for overlap when adding a new instance declaration,
        we check for overlap when looking up an Inst.  If we find more than one
        matching instance, we see if any of the candidates dominates the others
        (in the sense of being a substitution instance of all the others);
        and only if not do we report an error.
      
      
      
      	------------------------
      	     Medium things
      	------------------------
      
      * The TcRn monad is generalised a bit further.  It's now based on utils/IOEnv.lhs,
        the IO monad with an environment.  The desugarer uses the monad too,
        so that anything it needs can get faulted in nicely.
      
      * Reduce the number of wired-in things; in particular Word and Integer
        are no longer wired in.  The latter required HsLit.HsInteger to get a
        Type argument.  The 'derivable type classes' data types (:+:, :*: etc)
        are not wired in any more either (see stuff about derivable type classes
        below).
      
      * The PersistentComilerState is now held in a mutable variable
        in the HscEnv.  Previously (a) it was passed to and then returned by
        many top-level functions, which was painful; (b) it was invariably
        accompanied by the HscEnv.  This change tidies up top-level plumbing
        without changing anything important.
      
      * Derivable type classes are treated much more like 'deriving' clauses.
        Previously, the Ids for the to/from functions lived inside the TyCon,
        but now the TyCon simply records their existence (with a simple boolean).
        Anyone who wants to use them must look them up in the environment.
      
        This in turn makes it easy to generate the to/from functions (done
        in types/Generics) using HsSyn (like TcGenDeriv for ordinary derivings)
        instead of CoreSyn, which in turn means that (a) we don't have to figure
        out all the type arguments etc; and (b) it'll be type-checked for us.
        Generally, the task of generating the code has become easier, which is
        good for Manuel, who wants to make it more sophisticated.
      
      * A Name now says what its "parent" is. For example, the parent of a data
        constructor is its type constructor; the parent of a class op is its
        class.  This relationship corresponds exactly to the Avail data type;
        there may be other places we can exploit it.  (I made the change so that
        version comparison in interface files would be a bit easier; but in
        fact it tided up other things here and there (see calls to
        Name.nameParent).  For example, the declaration pool, of declararations
        read from interface files, but not yet used, is now keyed only by the 'main'
        name of the declaration, not the subordinate names.
      
      * New types OccEnv and OccSet, with the usual operations.
        OccNames can be efficiently compared, because they have uniques, thanks
        to the hashing implementation of FastStrings.
      
      * The GlobalRdrEnv is now keyed by OccName rather than RdrName.  Not only
        does this halve the size of the env (because we don't need both qualified
        and unqualified versions in the env), but it's also more efficient because
        we can use a UniqFM instead of a FiniteMap.
      
        Consequential changes to Provenance, which has moved to RdrName.
      
      * External Core remains a bit of a hack, as it was before, done with a mixture
        of HsDecls (so that recursiveness and argument variance is still inferred),
        and IfaceExprs (for value declarations).  It's not thoroughly tested.
      
      
      	------------------------
      	     Minor things
      	------------------------
      
      * DataCon fields dcWorkId, dcWrapId combined into a single field
        dcIds, that is explicit about whether the data con is a newtype or not.
        MkId.mkDataConWorkId and mkDataConWrapId are similarly combined into
        MkId.mkDataConIds
      
      * Choosing the boxing strategy is done for *source* type decls only, and
        hence is now in TcTyDecls, not DataCon.
      
      * WiredIn names are distinguished by their n_sort field, not by their location,
        which was rather strange
      
      * Define Maybes.mapCatMaybes :: (a -> Maybe b) -> [a] -> [b]
        and use it here and there
      
      * Much better pretty-printing of interface files (--show-iface)
      
      Many, many other small things.
      
      
      	------------------------
      	     File changes
      	------------------------
      * New iface/ subdirectory
      * Much of RnEnv has moved to iface/IfaceEnv
      * MkIface and BinIface have moved from main/ to iface/
      * types/Variance has been absorbed into typecheck/TcTyDecls
      * RnHiFiles and RnIfaces have vanished entirely.  Their
        work is done by iface/LoadIface
      * hsSyn/HsCore has gone, replaced by iface/IfaceSyn
      * typecheck/TcIfaceSig has gone, replaced by iface/TcIface
      * typecheck/TcMonoType has been renamed to typecheck/TcHsType
      * basicTypes/Var.hi-boot and basicTypes/Generics.hi-boot have gone altogether
      98688c6e
  31. 11 Dec, 2002 1 commit
  32. 18 Mar, 2002 1 commit
  33. 19 Nov, 2001 1 commit
  34. 27 Aug, 2001 1 commit
  35. 17 Aug, 2001 1 commit
    • apt's avatar
      [project @ 2001-08-17 17:18:51 by apt] · 1dfaee31
      apt authored
      How I spent my summer vacation.
      
      Primops
      -------
      
      The format of the primops.txt.pp file has been enhanced to allow
      (latex-style) primop descriptions to be included.  There is a new flag
      to genprimopcode that generates documentation including these
      descriptions. A first cut at descriptions of the more interesting
      primops has been made, and the file has been reordered a bit.
      
      31-bit words
      ------------
      
      The front end now can cope with the possibility of 31-bit (or even 30-bit)
      Int# and Word# types.  The only current use of this is to generate
      external .core files that can be translated into OCAML source files
      (OCAML uses a one-bit tag to distinguish integers from pointers).
      The only way to get this right now is by hand-defining the preprocessor
      symbol WORD_SIZE_IN_BITS, which is normally set automatically from
      the familiar WORD_SIZE_IN_BYTES.
      
      Just in case 31-bit words are used, we now have Int32# and Word32# primitive types
      and an associated family of operators, paralleling the existing 64-bit
      stuff.  Of course, none of the operators actually need to be implemented
      in the absence of a 31-bit backend.
      There has also been some minor re-jigging of the 32 vs. 64 bit stuff.
      See the description at the top of primops.txt.pp file for more details.
      Note that, for the first time, the *type* of a primop can now depend
      on the target word size.
      
      Also, the family of primops intToInt8#, intToInt16#, etc.
      have been renamed narrow8Int#, narrow16Int#, etc., to emphasize
      that they work on Int#'s and don't actually convert between types.
      
      Addresses
      ---------
      
      As another part of coping with the possibility of 31-bit ints,
      the addr2Int# and int2Addr# primops are now thoroughly deprecated
      (and not even defined in the 31-bit case) and all uses
      of them have been removed except from the (deprecated) module
      hslibs/lang/Addr
      
      Addr# should now be treated as a proper abstract type, and has these suitable operators:
      
      nullAddr# : Int# -> Addr# (ignores its argument; nullary primops cause problems at various places)
      plusAddr# :  Addr# -> Int# -> Addr#
      minusAddr : Addr# -> Addr# -> Int#
      remAddr# : Addr# -> Int# -> Int#
      
      Obviously, these don't allow completely arbitrary offsets if 31-bit ints are
      in use, but they should do for all practical purposes.
      
      It is also still possible to generate an address constant, and there is a built-in rule
      that makes use of this to remove the nullAddr# calls.
      
      Misc
      ----
      There is a new compile flag -fno-code that causes GHC to quit after generating .hi files
      and .core files (if requested) but before generating STG.
      
      Z-encoded names for tuples have been rationalized; e.g.,
      Z3H now means an unboxed 3-tuple, rather than an unboxed
      tuple with 3 commas (i.e., a 4-tuple)!
      
      Removed misc. litlits in hslibs/lang
      
      Misc. small changes to external core format.  The external core description
      has also been substantially updated, and incorporates the automatically-generated
      primop documentation; its in the repository at /papers/ext-core/core.tex.
      
      A little make-system addition to allow passing CPP options to compiler and
      library builds.
      1dfaee31
  36. 19 Jul, 2001 1 commit
  37. 01 Jun, 2001 1 commit