1. 02 May, 2007 1 commit
  2. 08 Nov, 2006 1 commit
  3. 11 Oct, 2006 1 commit
  4. 05 Oct, 2006 1 commit
  5. 29 Sep, 2006 1 commit
  6. 20 Sep, 2006 2 commits
    • chak@cse.unsw.edu.au.'s avatar
      Minor tidying up · 247fd641
      chak@cse.unsw.edu.au. authored
      Mon Sep 18 17:08:30 EDT 2006  Manuel M T Chakravarty <chak@cse.unsw.edu.au>
        * Minor tidying up
        Sun Aug  6 20:30:11 EDT 2006  Manuel M T Chakravarty <chak@cse.unsw.edu.au>
          * Minor tidying up
          Tue Aug  1 08:51:40 EDT 2006  simonpj@microsoft.com
    • chak@cse.unsw.edu.au.'s avatar
      Better pretty printing for CoPat · 58d200ac
      chak@cse.unsw.edu.au. authored
      Mon Sep 18 16:45:13 EDT 2006  Manuel M T Chakravarty <chak@cse.unsw.edu.au>
        * Better pretty printing for CoPat
        Sun Aug  6 17:25:19 EDT 2006  Manuel M T Chakravarty <chak@cse.unsw.edu.au>
          * Better pretty printing for CoPat
          Wed Jul 26 08:22:22 EDT 2006  simonpj@microsoft.com
  7. 15 Sep, 2006 1 commit
    • chak@cse.unsw.edu.au.'s avatar
      Massive patch for the first months work adding System FC to GHC #14 · 108361d0
      chak@cse.unsw.edu.au. authored
      Fri Aug  4 15:59:09 EDT 2006  Manuel M T Chakravarty <chak@cse.unsw.edu.au>
        * Massive patch for the first months work adding System FC to GHC #14
        Broken up massive patch -=chak
        Original log message:  
        This is (sadly) all done in one patch to avoid Darcs bugs.
        It's not complete work... more FC stuff to come.  A compiler
        using just this patch will fail dismally.
  8. 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.
  9. 03 Feb, 2006 1 commit
  10. 02 Feb, 2006 1 commit
  11. 10 Aug, 2005 1 commit
  12. 17 Apr, 2005 1 commit
  13. 04 Apr, 2005 2 commits
    • simonpj's avatar
      [project @ 2005-04-04 15:54:50 by simonpj] · 57bdd6a6
      simonpj authored
      More wibbles to HsSyn changes
    • simonpj's avatar
      [project @ 2005-04-04 11:55:11 by simonpj] · d551dbfe
      simonpj authored
      This commit combines three overlapping things:
      1.  Make rebindable syntax work for do-notation. The idea
          here is that, in particular, (>>=) can have a type that
          has class constraints on its argument types, e.g.
             (>>=) :: (Foo m, Baz a) => m a -> (a -> m b) -> m b
          The consequence is that a BindStmt and ExprStmt must have
          individual evidence attached -- previously it was one
          batch of evidence for the entire Do
          Sadly, we can't do this for MDo, because we use bind at
          a polymorphic type (to tie the knot), so we still use one
          blob of evidence (now in the HsStmtContext) for MDo.
          For arrow syntax, the evidence is in the HsCmd.
          For list comprehensions, it's all built-in anyway.
          So the evidence on a BindStmt is only used for ordinary
      2.  Tidy up HsSyn.  In particular:
      	- Eliminate a few "Out" forms, which we can manage
      	without (e.g. 
      	- It ought to be the case that the type checker only
      	decorates the syntax tree, but doesn't change one
      	construct into another.  That wasn't true for NPat,
      	LitPat, NPlusKPat, so I've fixed that.
      	- Eliminate ResultStmts from Stmt.  They always had
      	to be the last Stmt, which led to awkward pattern
      	matching in some places; and the benefits didn't seem
      	to outweigh the costs.  Now each construct that uses
      	[Stmt] has a result expression too (e.g. GRHS).
      3.  Make 'deriving( Ix )' generate a binding for unsafeIndex,
          rather than for index.  This is loads more efficient.
          (This item only affects TcGenDeriv, but some of point (2)
          also affects TcGenDeriv, so it has to be in one commit.)
  14. 31 Mar, 2005 1 commit
    • simonmar's avatar
      [project @ 2005-03-31 10:16:33 by simonmar] · 853e20a3
      simonmar authored
      Tweaks to get the GHC sources through Haddock.  Doesn't quite work
      yet, because Haddock complains about the recursive modules.  Haddock
      needs to understand SOURCE imports (it can probably just ignore them
      as a first attempt).
  15. 15 Oct, 2004 1 commit
  16. 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
          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
      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).
  17. 10 Dec, 2003 1 commit
    • simonmar's avatar
      [project @ 2003-12-10 14:15:16 by simonmar] · 55042138
      simonmar authored
      Add accurate source location annotations to HsSyn
      Every syntactic entity in HsSyn is now annotated with a SrcSpan, which
      details the exact beginning and end points of that entity in the
      original source file.  All honest compilers should do this, and it was
      about time GHC did the right thing.
      The most obvious benefit is that we now have much more accurate error
      messages; when running GHC inside emacs for example, the cursor will
      jump to the exact location of an error, not just a line somewhere
      nearby.  We haven't put a huge amount of effort into making sure all
      the error messages are accurate yet, so there could be some tweaking
      still needed, although the majority of messages I've seen have been
      Error messages now contain a column number in addition to the line
      number, eg.
         read001.hs:25:10: Variable not in scope: `+#'
      To get the full text span info, use the new option -ferror-spans.  eg.
         read001.hs:25:10-11: Variable not in scope: `+#'
      I'm not sure whether we should do this by default.  Emacs won't
      understand the new error format, for one thing.
      In a more elaborate editor setting (eg. Visual Studio), we can arrange
      to actually highlight the subexpression containing an error.  Eventually
      this information will be used so we can find elements in the abstract
      syntax corresponding to text locations, for performing high-level editor
      functions (eg. "tell me the type of this expression I just highlighted").
      Performance of the compiler doesn't seem to be adversely affected.
      Parsing is still quicker than in 6.0.1, for example.
      This was an excrutiatingly painful change to make: both Simon P.J. and
      myself have been working on it for the last three weeks or so.  The
      basic changes are:
       - a new datatype SrcSpan, which represents a beginning and end position
         in a source file.
       - To reduce the pain as much as possible, we also defined:
            data Located e = L SrcSpan e
       - Every datatype in HsSyn has an equivalent Located version.  eg.
            type LHsExpr id = Located (HsExpr id)
         and pretty much everywhere we used to use HsExpr we now use
         LHsExpr.  Believe me, we thought about this long and hard, and
         all the other options were worse :-)
      Additional changes/cleanups we made at the same time:
        - The abstract syntax for bindings is now less arcane.  MonoBinds
          and HsBinds with their built-in list constructors have gone away,
          replaced by HsBindGroup and HsBind (see HsSyn/HsBinds.lhs).
        - The various HsSyn type synonyms have now gone away (eg. RdrNameHsExpr,
          RenamedHsExpr, and TypecheckedHsExpr are now HsExpr RdrName,
          HsExpr Name, and HsExpr Id respectively).
        - Utilities over HsSyn are now collected in a new module HsUtils.
          More stuff still needs to be moved in here.
        - MachChar now has a real Char instead of an Int.  All GHC versions that
          can compile GHC now support 32-bit Chars, so this was a simplification.
  18. 20 Feb, 2003 1 commit
  19. 21 Nov, 2002 1 commit
    • simonpj's avatar
      [project @ 2002-11-21 09:36:03 by simonpj] · f0f69132
      simonpj authored
      	Fix and tidy the desugaring of
      	pattern-matching in do-notation
      In the reorgansiation of HsPat, failureFreePat had become incorrect (due to
      a catch-all case that caught a constructor that should have been matched).  So
      pattern-match failure in do-notation wasn't handled right.
      As it turned out, DsExpr.dsDo could be made much simpler and more elegant
      by using matchSimply instead of matchWrapper, and this had the side benefit
      of removing the last call to HsPat.failureFreePat.  So it's gone!
  20. 13 Sep, 2002 1 commit
    • simonpj's avatar
      [project @ 2002-09-13 15:02:25 by simonpj] · 9af77fa4
      simonpj authored
      	Make Template Haskell into the HEAD
      This massive commit transfers to the HEAD all the stuff that
      Simon and Tim have been doing on Template Haskell.  The
      meta-haskell-branch is no more!
      WARNING: make sure that you
        * Update your links if you are using link trees.
          Some modules have been added, some have gone away.
        * Do 'make clean' in all library trees.
          The interface file format has changed, and you can
          get strange panics (sadly) if GHC tries to read old interface files:
          e.g.  ghc-5.05: panic! (the `impossible' happened, GHC version 5.05):
      	  Binary.get(TyClDecl): ForeignType
        * You need to recompile the rts too; Linker.c has changed
      However the libraries are almost unaltered; just a tiny change in
      Base, and to the exports in Prelude.
      NOTE: so far as TH itself is concerned, expression splices work
      fine, but declaration splices are not complete.
      		The main change
      The main structural change: renaming and typechecking have to be
      interleaved, because we can't rename stuff after a declaration splice
      until after we've typechecked the stuff before (and the splice
      * Combine the renamer and typecheker monads into one
      	(TcRnMonad, TcRnTypes)
        These two replace TcMonad and RnMonad
      * Give them a single 'driver' (TcRnDriver).  This driver
        replaces TcModule.lhs and Rename.lhs
      * The haskell-src library package has a module
        which defines the Haskell data type seen by the TH programmer.
      * New modules:
      	hsSyn/Convert.hs 	converts THSyntax -> HsSyn
      	deSugar/DsMeta.hs 	converts HsSyn -> THSyntax
      * New module typecheck/TcSplice type-checks Template Haskell splices.
      		Linking stuff
      * ByteCodeLink has been split into
      	ByteCodeLink	(which links)
      	ByteCodeAsm	(which assembles)
      * New module ghci/ObjLink is the object-code linker.
      * compMan/CmLink is removed entirely (was out of place)
        Ditto CmTypes (which was tiny)
      * Linker.c initialises the linker when it is first used (no need to call
        initLinker any more).  Template Haskell makes it harder to know when
        and whether to initialise the linker.
      	Gathering the LIE in the type checker
      * Instead of explicitly gathering constraints in the LIE
      	tcExpr :: RenamedExpr -> TcM (TypecheckedExpr, LIE)
        we now dump the constraints into a mutable varabiable carried
        by the monad, so we get
      	tcExpr :: RenamedExpr -> TcM TypecheckedExpr
        Much less clutter in the code, and more efficient too.
        (Originally suggested by Mark Shields.)
      		Remove "SysNames"
      Because the renamer and the type checker were entirely separate,
      we had to carry some rather tiresome implicit binders (or "SysNames")
      along inside some of the HsDecl data structures.  They were both
      tiresome and fragile.
      Now that the typechecker and renamer are more intimately coupled,
      we can eliminate SysNames (well, mostly... default methods still
      carry something similar).
      		Clean up HsPat
      One big clean up is this: instead of having two HsPat types (InPat and
      OutPat), they are now combined into one.  This is more consistent with
      the way that HsExpr etc is handled; there are some 'Out' constructors
      for the type checker output.
      	HsPat.InPat	--> HsPat.Pat
      	HsPat.OutPat	--> HsPat.Pat
      	No 'pat' type parameter in HsExpr, HsBinds, etc
      	Constructor patterns are nicer now: they use
      	for the three cases of constructor patterns:
      		prefix, infix, and record-bindings
      	The *same* data type HsConDetails is used in the type
      	declaration of the data type (HsDecls.TyData)
      Lots of associated clean-up operations here and there.  Less code.
      Everything is wonderful.
  21. 09 Sep, 2002 1 commit
    • simonpj's avatar
      [project @ 2002-09-09 12:57:47 by simonpj] · 1e25bdc2
      simonpj authored
      	Fix rank-2 pattern-match failure
      This fixes the failure when you have a rank-2 type sig
      matching a data type pattern.  Thus
      	data T a = T1 | T2 a
      	f :: (forall x. T x) -> Int
      	f T1 = ...
      This crashes GHC 5.04
  22. 06 Jun, 2002 1 commit
  23. 05 Jun, 2002 1 commit
  24. 27 May, 2002 1 commit
    • simonpj's avatar
      [project @ 2002-05-27 16:13:42 by simonpj] · fd7d044f
      simonpj authored
      Make negative literals work in patterns
      The issue here is that
      	f (-1) = True
      	f x    = False
      should generate
      	f x = x == negate (fromInteger 1)
      rather than
      	f x = x == fromInteger (-1)
  25. 11 Feb, 2002 1 commit
    • chak's avatar
      [project @ 2002-02-11 08:20:38 by chak] · 10fcd78c
      chak authored
      		       * Merging from ghc-ndp-branch *
      This commit merges the current state of the "parallel array extension" and
      includes the following:
      * (Almost) completed Milestone 1:
        - The option `-fparr' activates the H98 extension for parallel arrays.
        - These changes have a high likelihood of conflicting (in the CVS sense)
          with other changes to GHC and are the reason for merging now.
        - ToDo: There are still some (less often used) functions not implemented in
      	  `PrelPArr' and a mechanism is needed to automatically import
      	  `PrelPArr' iff `-fparr' is given.  Documentation that should go into
      	  the Commentary is currently in `ghc/compiler/ndpFlatten/TODO'.
      * Partial Milestone 2:
        - The option `-fflatten' activates the flattening transformation and `-ndp'
          selects the "ndp" way (where all libraries have to be compiled with
          flattening).  The way option `-ndp' automagically turns on `-fparr' and
        - Almost all changes are in the new directory `ndpFlatten' and shouldn't
          affect the rest of the compiler.  The only exception are the options and
          the points in `HscMain' where the flattening phase is called when
          `-fflatten' is given.
        - This isn't usable yet, but already implements function lifting,
          vectorisation, and a new analysis that determines which parts of a module
          have to undergo the flattening transformation.  Missing are data structure
          and function specialisation, the unboxed array library (including fusion
          rules), and lots of testing.
      I have just run the regression tests on the thing without any problems.  So,
      it seems, as if we haven't broken anything crucial.
  26. 26 Nov, 2001 1 commit
    • simonpj's avatar
      [project @ 2001-11-26 09:20:25 by simonpj] · 5e3f005d
      simonpj authored
      	Implement Rank-N types
      This commit implements the full glory of Rank-N types, using
      the Odersky/Laufer approach described in their paper
      	"Putting type annotations to work"
      In fact, I've had to adapt their approach to deal with the
      full glory of Haskell (including pattern matching, and the
      scoped-type-variable extension).  However, the result is:
      * There is no restriction to rank-2 types.  You can nest forall's
        as deep as you like in a type.  For example, you can write a type
      	p :: ((forall a. Eq a => a->a) -> Int) -> Int
        This is a rank-3 type, illegal in GHC 5.02
      * When matching types, GHC uses the cunning Odersky/Laufer coercion
        rules.  For example, suppose we have
      	q :: (forall c. Ord c => c->c) -> Int
        Then, is this well typed?
      	x :: Int
      	x = p q
        Yes, it is, but GHC has to generate the right coercion.  Here's
        what it looks like with all the big lambdas and dictionaries put in:
      	x = p (\ f :: (forall a. Eq a => a->a) ->
      		 q (/\c \d::Ord c -> f c (eqFromOrd d)))
        where eqFromOrd selects the Eq superclass dictionary from the Ord
        dicationary:		eqFromOrd :: Ord a -> Eq a
      * You can use polymorphic types in pattern type signatures.  For
      	f (g :: forall a. a->a) = (g 'c', g True)
        (Previously, pattern type signatures had to be monotypes.)
      * The basic rule for using rank-N types is that you must specify
        a type signature for every binder that you want to have a type
        scheme (as opposed to a plain monotype) as its type.
        However, you don't need to give the type signature on the
        binder (as I did above in the defn for f).  You can give it
        in a separate type signature, thus:
      	f :: (forall a. a->a) -> (Char,Bool)
      	f g = (g 'c', g True)
        GHC will push the external type signature inwards, and use
        that information to decorate the binders as it comes across them.
        I don't have a *precise* specification of this process, but I
        think it is obvious enough in practice.
      * In a type synonym you can use rank-N types too.  For example,
        you can write
      	type IdFun = forall a. a->a
      	f :: IdFun -> (Char,Bool)
      	f g = (g 'c', g True)
        As always, type synonyms must always occur saturated; GHC
        expands them before it does anything else.  (Still, GHC goes
        to some trouble to keep them unexpanded in error message.)
      The main plan is as before.  The main typechecker for expressions,
      tcExpr, takes an "expected type" as its argument.  This greatly
      improves error messages.  The new feature is that when this
      "expected type" (going down) meets an "actual type" (coming up)
      we use the new subsumption function
      which checks that the actual type can be coerced into the
      expected type (and produces a coercion function to demonstrate).
      The main new chunk of code is TcUnify.tcSub.  The unifier itself
      is unchanged, but it has moved from TcMType into TcUnify.  Also
      checkSigTyVars has moved from TcMonoType into TcUnify.
      Result: the new module, TcUnify, contains all stuff relevant
      to subsumption and unification.
      Unfortunately, there is now an inevitable loop between TcUnify
      and TcSimplify, but that's just too bad (a simple TcUnify.hi-boot
      All of this doesn't come entirely for free.  Here's the typechecker
      line count (INCLUDING comments)
      	Before	16,551
      	After	17,116
  27. 13 Jul, 2001 1 commit
    • simonpj's avatar
      [project @ 2001-07-13 13:29:56 by simonpj] · d4e38936
      simonpj authored
      	Tidy up the "syntax rebinding" story
      I found a bug in the code that dealt with re-binding implicit
      numerical syntax:
      	literals 	(fromInteger/fromRational)
      	negation	(negate)
      	n+k patterns	(minus)
      This is triggered by the -fno-implicit-prelude flag, and it
      used to be handled via the PrelNames.SyntaxMap.
      But I found a nicer way to do it that involves much less code,
      and doesn't have the bug.  The explanation is with
  28. 28 May, 2001 1 commit
  29. 26 Feb, 2001 1 commit
    • simonmar's avatar
      [project @ 2001-02-26 15:06:57 by simonmar] · 1c62b517
      simonmar authored
      Implement do-style bindings on the GHCi command line.
      The syntax for a command-line is exactly that of a do statement, with
      the following meanings:
        - `pat <- expr'
          performs expr, and binds each of the variables in pat.
        - `let pat = expr; ...'
          binds each of the variables in pat, doesn't do any evaluation
        - `expr'
          behaves as `it <- expr' if expr is IO-typed, or `let it = expr'
          followed by `print it' otherwise.
  30. 20 Feb, 2001 1 commit
    • simonpj's avatar
      [project @ 2001-02-20 09:40:43 by simonpj] · 5e624292
      simonpj authored
      Decoupling the Prelude [HsExpr, HsLit, HsPat, ParseUtil, Parser.y, PrelNames,
      ~~~~~~~~~~~~~~~~~~~~~~  Rename, RnEnv, RnExpr, RnHsSyn, Inst, TcEnv, TcMonad,
      			TcPat, TcExpr]
      The -fno-implicit-prelude flag is meant to arrange that when you write
      you get
      	fromInt 3
      where 'fromInt' is whatever fromInt is in scope at the top level of
      the module being compiled.  Similarly for
      	* numeric patterns
      	* n+k patterns
      	* negation
      This used to work, but broke when we made the static/dynamic flag distinction.
      It's now tidied up a lot.  Here's the plan:
        - PrelNames contains sugarList :: SugarList, which maps built-in names
          to the RdrName that should replace them.  
        - The renamer makes a finite map :: SugarMap, which maps the built-in names
          to the Name of the re-mapped thing
        - The typechecker consults this map via tcLookupSyntaxId when it is doing
          numeric things
      At present I've only decoupled numeric syntax, since that is the main demand,
      but the scheme is much more robustly extensible than the previous method.
      As a result some HsSyn constructors don't need to carry names in them
      (notably HsOverLit, NegApp, NPlusKPatIn)
  31. 23 Oct, 2000 1 commit
  32. 03 Oct, 2000 1 commit
    • simonpj's avatar
      [project @ 2000-10-03 08:43:00 by simonpj] · 710e2074
      simonpj authored
      	Adding generics		SLPJ Oct 2000
      This big commit adds Hinze/PJ-style generic class definitions, based
      on work by Andrei Serjantov.  For example:
        class Bin a where
          toBin   :: a -> [Int]
          fromBin :: [Int] -> (a, [Int])
          toBin {| Unit |}    Unit	  = []
          toBin {| a :+: b |} (Inl x)   = 0 : toBin x
          toBin {| a :+: b |} (Inr y)   = 1 : toBin y
          toBin {| a :*: b |} (x :*: y) = toBin x ++ toBin y
          fromBin {| Unit |}    bs      = (Unit, bs)
          fromBin {| a :+: b |} (0:bs)  = (Inl x, bs')    where (x,bs') = fromBin bs
          fromBin {| a :+: b |} (1:bs)  = (Inr y, bs')    where (y,bs') = fromBin bs
          fromBin {| a :*: b |} bs  	  = (x :*: y, bs'') where (x,bs' ) = fromBin bs
      							  (y,bs'') = fromBin bs'
      Now we can say simply
        instance Bin a => Bin [a]
      and the compiler will derive the appropriate code automatically.
      		(About 9k lines of diffs.  Ha!)
      Generic related things
      * basicTypes/BasicTypes: The EP type (embedding-projection pairs)
      * types/TyCon:
      	An extra field in an algebraic tycon (genInfo)
      * types/Class, and hsSyn/HsBinds:
      	Each class op (or ClassOpSig) carries information about whether
      	it  	a) has no default method
      		b) has a polymorphic default method
      		c) has a generic default method
      	There's a new data type for this: Class.DefMeth
      * types/Generics:
      	A new module containing good chunk of the generic-related code
      	It has a .hi-boot file (alas).
      * typecheck/TcInstDcls, typecheck/TcClassDcl:
      	Most of the rest of the generics-related code
      * hsSyn/HsTypes:
      	New infix type form to allow types of the form
      		data a :+: b = Inl a | Inr b
      * parser/Parser.y, Lex.lhs, rename/ParseIface.y:
      	Deal with the new syntax
      * prelude/TysPrim, TysWiredIn:
      	Need to generate generic stuff for the wired-in TyCons
      * rename/RnSource RnBinds:
      	A rather gruesome hack to deal with scoping of type variables
      	from a generic patterns.  Details commented in the ClassDecl
      	case of RnSource.rnDecl.
      	Of course, there are many minor renamer consequences of the
      	other changes above.
      * lib/std/PrelBase.lhs
      	Data type declarations for Unit, :+:, :*:
      Slightly unrelated housekeeping
      * hsSyn/HsDecls:
      	ClassDecls now carry the Names for their implied declarations
      	(superclass selectors, tycon, etc) in a list, rather than
      	laid out one by one.  This simplifies code between the parser
      	and the type checker.
      * prelude/PrelNames, TysWiredIn:
      	All the RdrNames are now together in PrelNames.
      * utils/ListSetOps:
      	Add finite mappings based on equality and association lists (Assoc a b)
      	Move stuff from List.lhs that is related
  33. 22 Sep, 2000 1 commit
    • simonpj's avatar
      [project @ 2000-09-22 15:56:12 by simonpj] · 1bba522f
      simonpj authored
      	Tidying up HsLit, and making it possible to define
      		your own numeric library
      		Simon PJ 22 Sept 00
      ** NOTE: I did these changes on the aeroplane.  They should compile,
      	 and the Prelude still compiles OK, but it's entirely 
      	 possible that I've broken something
      The original reason for this many-file but rather shallow
      commit is that it's impossible in Haskell to write your own
      numeric library.  Why?  Because when you say '1' you get 
      (Prelude.fromInteger 1), regardless of what you hide from the
      Prelude, or import from other libraries you have written.  So the
      idea is to extend the -fno-implicit-prelude flag so that 
      in addition to no importing the Prelude, you can rebind 
      	fromInteger	-- Applied to literal constants
      	fromRational	-- Ditto
      	negate		-- Invoked by the syntax (-x)
      	the (-) used when desugaring n+k patterns
      After toying with other designs, I eventually settled on a simple,
      crude one: rather than adding a new flag, I just extended the
      semantics of -fno-implicit-prelude so that uses of fromInteger,
      fromRational and negate are all bound to "whatever is in scope" 
      rather than "the fixed Prelude functions".  So if you say
      	{-# OPTIONS -fno-implicit-prelude #-}
      	module M where
       	import MyPrelude( fromInteger )
      	x = 3
      the literal 3 will use whatever (unqualified) "fromInteger" is in scope,
      in this case the one gotten from MyPrelude.
      On the way, though, I studied how HsLit worked, and did a substantial tidy
      up, deleting quite a lot of code along the way.  In particular.
      * HsBasic.lhs is renamed HsLit.lhs.  It defines the HsLit type.
      * There are now two HsLit types, both defined in HsLit.
      	HsLit for non-overloaded literals (like 'x')
      	HsOverLit for overloaded literals (like 1 and 2.3)
      * HsOverLit completely replaces Inst.OverloadedLit, which disappears.
        An HsExpr can now be an HsOverLit as well as an HsLit.
      * HsOverLit carries the Name of the fromInteger/fromRational operation,
        so that the renamer can help with looking up the unqualified name 
        when -fno-implicit-prelude is on.  Ditto the HsExpr for negation.
        It's all very tidy now.
      * RdrHsSyn contains the stuff that handles -fno-implicit-prelude
        (see esp RdrHsSyn.prelQual).  RdrHsSyn also contains all the "smart constructors"
        used by the parser when building HsSyn.  See for example RdrHsSyn.mkNegApp
        (previously the renamer (!) did the business of turning (- 3#) into -3#).
      * I tidied up the handling of "special ids" in the parser.  There's much
        less duplication now.
      * Move Sven's Horner stuff to the desugarer, where it belongs.  
        There's now a nice function DsUtils.mkIntegerLit which brings together
        related code from no fewer than three separate places into one single
        place.  Nice!
      * A nice tidy-up in MatchLit.partitionEqnsByLit became possible.
      * Desugaring of HsLits is now much tidier (DsExpr.dsLit)
      * Some stuff to do with RdrNames is moved from ParseUtil.lhs to RdrHsSyn.lhs,
        which is where it really belongs.
      * I also removed 
      	many unnecessary imports from modules 
      	quite a bit of dead code
        in divers places
  34. 14 Jul, 2000 1 commit
    • simonpj's avatar
      [project @ 2000-07-14 08:17:36 by simonpj] · 77a8c0db
      simonpj authored
      This commit completely re-does the kind-inference mechanism.
      Previously it was inter-wound with type inference, but that was
      always hard to understand, and it finally broke when we started
      checking for ambiguity when type-checking a type signature (details
      So now kind inference is more clearly separated, so that it never
      takes place at the same time as type inference.  The biggest change
      is in TcTyClsDecls, which does the kind inference for a group of
      type and class declarations.  It now contains comments to explain
      how it all works.
      There are also comments in TypeRep which describes the slightly
      tricky way in which we deal with the fact that kind 'type' (written
      '*') actually has 'boxed type' and 'unboxed type' as sub-kinds.
      The whole thing is a bit of a hack, because we don't really have 
      sub-kinding, but it's less of a hack than before.
      A lot of general tidying up happened at the same time.
      In particular, I removed some dead code here and there
  35. 25 May, 2000 1 commit
    • simonpj's avatar
      [project @ 2000-05-25 12:41:14 by simonpj] · 495ef8bd
      simonpj authored
      		Apr/May 2000
      This is a pretty big commit!  It adds stuff I've been working on
      over the last month or so.  DO NOT MERGE IT WITH 4.07!
      Interface file formats have changed a little; you'll need
      to make clean before remaking.
      						Simon PJ
      Recompilation checking
      Substantial improvement in recompilation checking.  The version management
      is now entirely internal to GHC.  ghc-iface.lprl is dead!
      The trick is to generate the new interface file in two steps:
        - first convert Types etc to HsTypes etc, and thereby
      	build a new ParsedIface
        - then compare against the parsed (but not renamed) version of the old
      	interface file
      Doing this meant adding code to convert *to* HsSyn things, and to
      compare HsSyn things for equality.  That is the main tedious bit.
      Another improvement is that we now track version info for
      fixities and rules, which was missing before.
      Interface file reading
      Make interface files reading more robust.
        * If the old interface file is unreadable, don't fail. [bug fix]
        * If the old interface file mentions interfaces
          that are unreadable, don't fail. [bug fix]
        * When we can't find the interface file,
          print the directories we are looking in.  [feature]
      Type signatures
        * New flag -ddump-types to print type signatures
      Type pruning
      When importing
      	data T = T1 A | T2 B | T3 C
      it seems excessive to import the types A, B, C as well, unless
      the constructors T1, T2 etc are used.  A,B,C might be more types,
      and importing them may mean reading more interfaces, and so on.
       So the idea is that the renamer will just import the decl
      	data T
      unless one of the constructors is used.  This turns out to be quite
      easy to implement.  The downside is that we must make sure the
      constructors are always available if they are really needed, so
      I regard this as an experimental feature.
      Elimininate ThinAir names
      Eliminate ThinAir.lhs and all its works.  It was always a hack, and now
      the desugarer carries around an environment I think we can nuke ThinAir
      As part of this, I had to move all the Prelude RdrName defns from PrelInfo
      to PrelMods --- so I renamed PrelMods as PrelNames.
      I also had to move the builtinRules so that they are injected by the renamer
      (rather than appearing out of the blue in SimplCore).  This is if anything simpler.
      * Tidy up the data types involved in Rules
      * Eliminate RnEnv.better_provenance; use Name.hasBetterProv instead
      * Add Unique.hasKey :: Uniquable a => a -> Unique -> Bool
        It's useful in a lot of places
      * Fix a bug in interface file parsing for __U[!]
  36. 27 Jan, 1999 1 commit
    • simonpj's avatar
      [project @ 1999-01-27 14:51:14 by simonpj] · 18976e61
      simonpj authored
      Finally!  This commits the ongoing saga of Simon's hygiene sweep
      a) The 'unused variable' warnings from the renamer work.  
      b) Better error messages here and there, esp type checker
      c) Fixities for Haskell 98 (maybe I'd done that before)
      d) Lazy reporting of name clashes for Haskell 98 (ditto)
      a) type OccName has its own module.  OccNames are represented
         by a single FastString, not three as in the last round.  This
         string is held in Z-encoded form; a decoding function decodes
         for printing in user error messages.  There's a nice tight
         encoding for (,,,,,,,,,,,,,,,,,,,,,,,,,,,,,)
      b) type Module is a proper ADT, in module OccName
      c) type RdrName is a proper ADT, in its own module
      d) type Name has a new, somwhat tidier, representation
      e) much grunting in the renamer to get Provenances right.
         This makes error messages look better (no spurious qualifiers)
  37. 24 Jan, 1999 1 commit
  38. 18 Dec, 1998 1 commit
    • simonpj's avatar
      [project @ 1998-12-18 17:40:31 by simonpj] · 7e602b0a
      simonpj authored
      Another big commit from Simon.  Actually, the last one
      didn't all go into the main trunk; because of a CVS glitch it
      ended up in the wrong branch.
      So this commit includes:
      * Scoped type variables
      * Warnings for unused variables should work now (they didn't before)
      * Simplifier improvements:
      	- Much better treatment of strict arguments
      	- Better treatment of bottoming Ids
      	- No need for w/w split for fns that are merely strict
      	- Fewer iterations needed, I hope
      * Less gratuitous renaming in interface files and abs C
      * OccName is a separate module, and is an abstract data type
      I think the whole Prelude and Exts libraries compile correctly.
      Something isn't quite right about typechecking existentials though.