DarcsURL: http://darcs.haskell.org/ghc MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="=_" --=_ Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Sat Feb 25 21:59:45 GMT Standard Time 2006 claus.reinke@talk21.com * these tables have four columns, not three --=_ Content-Type: text/x-darcs-patch Content-Transfer-Encoding: quoted-printable Content-Description: A darcs patch for your repository! New patches: [these tables have four columns, not three claus.reinke@talk21.com**20060225215945] { hunk ./ghc/docs/users_guide/flags.xml 16 - + hunk ./ghc/docs/users_guide/flags.xml 97 - + hunk ./ghc/docs/users_guide/flags.xml 148 - + hunk ./ghc/docs/users_guide/flags.xml 193 - + hunk ./ghc/docs/users_guide/flags.xml 262 - + hunk ./ghc/docs/users_guide/flags.xml 307 - + hunk ./ghc/docs/users_guide/flags.xml 334 - + hunk ./ghc/docs/users_guide/flags.xml 369 - + hunk ./ghc/docs/users_guide/flags.xml 417 - + hunk ./ghc/docs/users_guide/flags.xml 446 - + hunk ./ghc/docs/users_guide/flags.xml 479 - + hunk ./ghc/docs/users_guide/flags.xml 536 - + hunk ./ghc/docs/users_guide/flags.xml 646 - + hunk ./ghc/docs/users_guide/flags.xml 813 - + hunk ./ghc/docs/users_guide/flags.xml 846 - + hunk ./ghc/docs/users_guide/flags.xml 1030 - + hunk ./ghc/docs/users_guide/flags.xml 1089 - + hunk ./ghc/docs/users_guide/flags.xml 1128 - + hunk ./ghc/docs/users_guide/flags.xml 1173 - + hunk ./ghc/docs/users_guide/flags.xml 1201 - + hunk ./ghc/docs/users_guide/flags.xml 1240 - + hunk ./ghc/docs/users_guide/flags.xml 1349 - + hunk ./ghc/docs/users_guide/flags.xml 1429 - + hunk ./ghc/docs/users_guide/flags.xml 1500 - + hunk ./ghc/docs/users_guide/flags.xml 1534 - + hunk ./ghc/docs/users_guide/flags.xml 1562 - + hunk ./ghc/docs/users_guide/flags.xml 1821 - + } Context: [NCG: Fix Typo in Register Allocator Loop Patch wolfgang.thaller@gmx.net**20060225033954 = Fix previous patch "NCG: Handle loops in register allocator" Of course, I broke it when correcting a style problem just before committi= ng. ] = [NCG: Handle loops in register allocator wolfgang.thaller@gmx.net**20060225031434 = Fill in the missing parts in the register allocator so that it can handle loops. = *) The register allocator now runs in the UniqSuppy monad, as it needs to be able to generate unique labels for fixup code blocks. = *) A few functions have been added to RegAllocInfo: mkRegRegMoveInstr -- generates a good old move instruction mkBranchInstr -- used to be MachCodeGen.genBranch patchJump -- Change the destination of a jump = *) The register allocator now makes sure that only one spill slot is used for each temporary, even if it is spilled and reloaded several times. This obviates the need for memory-to-memory moves in fixup code. = LIMITATIONS: = *) The case where the fixup code needs to cyclically permute a group of registers is currently unhandled. This will need more work once we come accross code where this actually happens. = *) Register allocation for code with loop is probably very inefficient (both at compile-time and at run-time). = *) We still cannot compile the RTS via NCG, for various other reasons. = ] = [Oops, I got a little trigger happy while trimming package.conf.in. Lemmih **20060224223704] = [Prettify parts of RnNames. No change of functionality. Lemmih **20060224215020] = [Remove duplicate code from RnNames. Lemmih **20060224212748] = [Remove non-existing modules from package.conf.in Lemmih **20060224203727] = [Remove some unused bindings frm RnNames. Lemmih **20060224165409] = [Rather large refactoring of RnNames. Lemmih **20060224154704 = This restructoring makes the renamed export and import lists available in IDE mode. = ] = [add file to go with "extract some of the generic..." patch Simon Marlow **20060224144126] = [oops, undo accidental addition of package-time settings Simon Marlow **20060224143051] = [turn off a trace Simon Marlow **20060224124608] = [add instance Outputable CLabel Simon Marlow **20060224124349] = [-O2 implies -optc-O2 now Simon Marlow **20060224124033] = [extract some of the generic C-- optimisations from the NCG Simon Marlow **20060224111753] = [lag/drag/void: add an extra assertion, and some commentary Simon Marlow **20060223155120] = [lag/drag/void profiling fix Simon Marlow **20060223155046 = We were searching the wrong part of the heap for dead objects, this was broken by recent changes to the step structure: from-space is now in step->old_blocks, not step->blocks. Fortunately some assertions in ProfHeap picked up the problem. ] = [add (trivial) support for STM objects in lag/drag/void profiling Simon Marlow **20060223154859] = [bugfix for LDV profiling on 64-bit platforms Simon Marlow **20060223150904 = There was an integer overflow in the definition of LDV_RECORD_CREATE when StgWord is 64 bits. ] = [warning fix Simon Marlow **20060223144537] = [further fix for floating point primitives Simon Marlow **20060223143013] = [Comment wibbles simonpj@microsoft.com**20060223142101] = [Wibbles to instance validity checking simonpj@microsoft.com**20060223134154] = [Fix comment simonpj@microsoft.com**20060223130104] = [Improve error reporting for type-improvement errors simonpj@microsoft.com**20060223130029] = [Reject polytypes in instance declarations (for now anyway) simonpj@microsoft.com**20060223125958] = [Remove duplicate comment simonpj@microsoft.com**20060210104028] = [Add renamed fixities to HsGroup. Lemmih **20060222173648] = [oops, initialize atomic_modify_mutvar_mutex Simon Marlow **20060222163827] = [check black holes before doing GC in scheduleDoHeapProfile() Simon Marlow **20060222160733 = fixes #687, see comment for details. ] = [fix for ASSIGN_BaseReg() in the unregisterised way Simon Marlow **20060222141836] = [floating-point fix for x86_64 Simon Marlow **20060222140719 = For 32-bit float primtives like sinFloat#, we currently call the double versions of the C library functions (sin(), cos() etc.). It seems more correct to call the float versions (sinf(), cosf() etc.). This makes a difference on x86_64, I'm not entirely sure why, but this way at least generates more consistent results and avoids extra promotion/demotion instructions when calling these primitives. = ] = [fix a deadlock in atomicModifyMutVar# Simon Marlow **20060221163711 = atomicModifyMutVar# was re-using the storage manager mutex (sm_mutex) to get its atomicity guarantee in SMP mode. But recently the addition of a call to dirty_MUT_VAR() to implement the read barrier lead to a rare deadlock case, because dirty_MUT_VAR() very occasionally needs to allocate a new block to chain on the mutable list, which requires sm_mutex. ] = [warning fix Simon Marlow **20060221163308] = [Mention the 'Encoding' module in package.conf.in Lemmih **20060221105147] = [Loosen the rules for instance declarations (Part 3) Ross Paterson **20060213161044 = Relax the restrictions on derived instances in the same way, so we can write = data MinHeap h a =3D H a (h a) deriving (Show) ] = [If we don't have libreadline then we need some dummy definition for comple= te* functions. kr.angelov@gmail.com**20060212095019] = [SMP bugfix: reload capability from task->cap after scheduleDoGC wolfgang.thaller@gmx.net**20060212034736] = [SMP support (xchg(), cas() and mb()) for PowerPC wolfgang.thaller@gmx.net**20060212033352] = [Bugfix in completion code for :set and :unset. Lemmih **20060210181319] = [Completion for :set, :unset and :undef. Lemmih **20060210171728] = [oops, forgot some more SMP->THREADED_RTS conversions Simon Marlow **20060210153236] = [fix test for REG_BaseReg (it's spelled REG_Base) Simon Marlow **20060210123552] = [Change CVS for _darcs in dirs to prune during make dist Duncan Coutts **20060209093204] = [fix for dirty_MUT_VAR: don't try to recordMutableCap in gen 0 Simon Marlow **20060210120021] = [STM fix from Tim Harris Simon Marlow **20060210112111 = Fixes assertion failures with STM and -debug. Tim says: Sorry, it's a problem in how nested transactions are handled in non-SMP builds. It'll bite when trying to commit a nested transaction which has read from a TVar but not updated it. = The call to validate_and_acquire_ownership in stmCommitNestedTransaction should be the same as that in stmCommitNestedTransaction, i.e.: = result =3D validate_and_acquire_ownership(trec, (!use_read_phase), TRUE)= ; = ] = [improvement to the deadlock detection Simon Marlow *-20060209123056 = When the RTS is idle, as detected by the timer signal, instead of prodding capabilities from the signal handler (which is not guaranteed to work - pthread_cond_signal() can't be called from signal handlers), create a new thread to do it. ] = [Simplify the -B handling. The interface to the ghc library has changed sli= ghtly. Lemmih **20060210094601] = [Fix desugaring of unboxed tuples simonpj@microsoft.com**20060209175328 = This patch is a slightly-unsatisfactory fix to desugaring unboxed tuples; it fixes ds057 which has been failing for some time. = Unsatisfactory because rather ad hoc -- but that applies to lots of the unboxed tuple stuff. = = ] = [x86_64: fix case of out-of-range operands to leaq Simon Marlow **20060209162247] = [Merge the smp and threaded RTS ways Simon Marlow **20060209154449 = Now, the threaded RTS also includes SMP support. The -smp flag is a synonym for -threaded. The performance implications of this are small to negligible, and it results in a code cleanup and reduces the number of combinations we have to test. ] = [change dirty_MUT_VAR() to use recordMutableCap() Simon Marlow **20060209150420 rather than recordMutableGen(), the former works better in SMP ] = [improvement to the deadlock detection Simon Marlow **20060209123056 = When the RTS is idle, as detected by the timer signal, instead of prodding capabilities from the signal handler (which is not guaranteed to work - pthread_cond_signal() can't be called from signal handlers), create a new thread to do it. ] = [Fix typo simonpj@microsoft.com**20060209124208] = [Fix instance rules for functional dependencies simonpj@microsoft.com**20060209113531 = GHC 6.4 implements a rather relaxed version of the Coverage Condition which is actually too relaxed: the compiler can get into an infinite loop as a result. = This commit fixes the problem (see Note [Coverage condition] in FunDeps.lh= s) and documents the change. = I also took the opportunity to add documentation about functional dependen= cies, taken from the Hugs manual with kind permission of Mark Jones = ] = [fix for the unregisterised way Simon Marlow **20060209105058 = We always assign to BaseReg on return from resumeThread(), but in cases where BaseReg is not an lvalue (eg. unreg) we need to disable this assigment. See comments for more details. ] = [prof/smp combination probably doesn't work, disable it Simon Marlow **20060209104815] = [tiny panic msg fix Simon Marlow **20060209102540] = [Loosen the rules for instance declarations (Part 2) simonpj@microsoft.com**20060209102129 = Tidying up to Ross's patch, plus adding documenation for it. = = ] = [relaxed instance termination test Ross Paterson **20060206111651 = With -fglasgow-exts but not -fallow-undecidable-instances, GHC 6.4 requires that instances be of the following form: = (1) each assertion in the context must constrain distinct variables mentioned in the head, and = (2) at least one argument of the head must be a non-variable type. = This patch replaces these rules with the requirement that each assertion in the context satisfy = (1) no variable has more occurrences in the assertion than in the head, a= nd = (2) the assertion has fewer constructors and variables (taken together and counting repetitions) than the head. = This allows all instances permitted by the old rule, plus such instances a= s = instance C a instance Show (s a) =3D> Show (Sized s a) instance (Eq a, Show b) =3D> C2 a b instance C2 Int a =3D> C3 Bool [a] instance C2 Int a =3D> C3 [a] b instance C4 a a =3D> C4 [a] [a] = but still ensures that under any substitution assertions in the context will be smaller than the head, so context reduction must terminate. = This is probably the best we can do if we consider each instance in isolation. ] = [Fix CPP failure by adding space before hASH_TBL_SIZE simonpj@microsoft.com**20060209093704] = [an LDV profiling fix (might just fix ASSERTIONs, I'm not sure) Simon Marlow **20060208170744] = [Do type refinement in TcIface simonpj@microsoft.com**20060208154412 = This commit fixes a bug in 6.4.1 and the HEAD. Consider this code, recorded **in an interface file** = \(x::a) -> case y of = MkT -> case x of { True -> ... } (where MkT forces a=3DBool) = In the "case x" we need to know x's type, because we use that to find which module to look for "True" in. x's type comes from the envt, so we must refine the envt. = = The alternative would be to record more info with an IfaceCase, but that would change the interface file format. = (This stuff will go away when we have proper coercions.) = ] = [Add mapOccEnv simonpj@microsoft.com**20060208154343] = [A little more debug printing simonpj@microsoft.com**20060208150701] = [Show types of case result when debug is on simonpj@microsoft.com**20060208150357] = [fix installation of binary dist when the PS docs aren't present Simon Marlow **20060208153259 = Fixes #660 ] = [fix a bug in closure_sizeW_() Simon Marlow **20060208145451] = [make the smp way RTS-only, normal libraries now work with -smp Simon Marlow **20060208143348 = We had to bite the bullet here and add an extra word to every thunk, to enable running ordinary libraries on SMP. Otherwise, we would have needed to ship an extra set of libraries with GHC 6.6 in addition to the two sets we already ship (normal + profiled), and all Cabal packages would have to be compiled for SMP too. We decided it best just to take the hit now, making SMP easily accessible to everyone in GHC 6.6. = Incedentally, although this increases allocation by around 12% on average, the performance hit is around 5%, and much less if your inner loop doesn't use any laziness. ] = [add -dfaststring-stats to dump some stats about the FastString hash table Simon Marlow **20060208131018] = [fix a warning Simon Marlow **20060207132323] = [catch up with changes to Distribution.ParseUtils.ParseResult Simon Marlow **20060207111111] = [Wibble to type signature simonpj@microsoft.com**20060207171254] = [Empty forall should disable implicit quantification simonpj@microsoft.com**20060207085137] = [Remove unused constructor in SourceTypeCtxt simonpj@microsoft.com**20060206112031] = [Basic completion in GHCi Simon Marlow **20060206122654 = This patch adds completion support to GHCi when readline is being used. Completion of identifiers (in scope only, but including qualified identifiers) in expressions is provided. Also, completion of commands (:cmd), and special completion for certain commands (eg. module names for the :module command) are also provided. ] = [Improve error report for pattern guards simonpj@microsoft.com**20060206101730] = [Add bang patterns simonpj@microsoft.com**20060203175108 = This commit adds bang-patterns, = enabled by -fglasgow-exts or -fbang-patterns diabled by -fno-bang-patterns = The idea is described here http://haskell.galois.com/cgi-bin/haskell-prime/trac.cgi/wiki/BangPattern= s = ] = [Add Bag.anyBag (analogous to List.any) simonpj@microsoft.com**20060203174627] = [Deal correctly with lazy patterns and GADTs simonpj@microsoft.com**20060202130409] = [Record the type in TuplePat (necessary for GADTs) simonpj@microsoft.com**20060202124405 = We must record the type of a TuplePat after typechecking, just like a ConP= atOut, so that desugaring works correctly for GADTs. See comments with the declar= ation of HsPat.TuplePat, and test gadt15 = ] = [Improve error reporting in Core Lint simonpj@microsoft.com**20060202124327] = [don't clean ghc-inplace when cleaning stages other than 1 Simon Marlow **20060202124359] = [Improve error reporting in typechecker simonpj@microsoft.com**20060201170332] = [Trim imports simonpj@microsoft.com**20060201170248] = [Yet another fix to an old hi-boot-6 file simonpj@microsoft.com**20060201105544] = [Kinding wibble in TH brackets simonpj@microsoft.com**20060131175730] = [Use extraGHCiLibraries (if supplied) in GHCi linker rather than extraLibra= ries Duncan Coutts **20051207105654 Also extend the parser. ] = [combine libraries/.darcs-boring and .darcs-boring Simon Marlow **20060131161530] = [Fix long-standing bug in CPR analysis simonpj@microsoft.com**20060131153247 = MERGE TO STABLE = For a long time (2002!) the CPR analysis done by dmdAnalTopRhs has been bogus. In particular, it's possible for a newtype constructor to look CPR-ish when it simply isn't. = This fixes it. Test is stranal/newtype = = = ] = [More hi-boot-6 updates simonpj@microsoft.com**20060131130926] = [Fix TcUnify.subFunTys in AppTy case simonpj@microsoft.com**20060131122420 = subFunTys wasn't dealing correctly with the case where the type to be split was of form (a ty1), where a is a type variable. = This shows up when compiling = Control.Arrow.Transformer.Stream in package arrows. = This commit fixes it. = = ] = [Error message wibble simonpj@microsoft.com**20060130163651] = [Add mkHsCoerce to avoid junk in typechecked code simonpj@microsoft.com**20060130131231 = Avoiding identity coercions is a Good Thing generally, but it turns out that the desugarer has trouble recognising = 'otherwise' and 'True' guards if they are wrapped in an identity coercion; and that leads to bogus overlap warnings. = ] = [Improve error messsage when argument count varies simonpj@microsoft.com**20060130131133] = [fix bug #664 in printSample() Simon Marlow **20060130115301 printSample() was attempting to round the fractional part of the time, but not propagated to the non-fractional part. It's probably better not to attempt to round the time at all. ] = [Fix hi-boot file for earlier versions of GHC simonpj@microsoft.com**20060127175040] = [Fix typo in boxy matching simonpj@microsoft.com**20060127174536] = [fix one case where -q wasn't honoured Simon Marlow **20060127104715] = [Check for GMP.framework on all Darwin platforms, not just PPC wolfgang.thaller@gmx.net**20060126071504] = [Simon's big boxy-type commit simonpj@microsoft.com**20060125162832 = This very large commit adds impredicativity to GHC, plus numerous other small things. = *** WARNING: I have compiled all the libraries, and *** a stage-2 compiler, and everything seems *** fine. But don't grab this patch if you = *** can't tolerate a hiccup if something is *** broken. = The big picture is this: = a) GHC handles impredicative polymorphism, as described in the "Boxy types: type inference for higher-rank types and impredicativity" paper = b) GHC handles GADTs in the new simplified (and very sligtly less epxrssive) way described in the "Simple unification-based type inference for GADTs" paper = = But there are lots of smaller changes, and since it was pre-Darcs they are not individually recorded. = Some things to watch out for: = c) The story on lexically-scoped type variables has changed, as per my email. I append the story below for completeness, but I = am still not happy with it, and it may change again. In particular, the new story does not allow a pattern-bound scoped type variable to be wobbly, so (\(x::[a]) -> ...) is usually rejected. This is more restrictive than before, and we might loosen up again. = d) A consequence of adding impredicativity is that GHC is a bit less gung ho about converting automatically between (ty1 -> forall a. ty2) and (forall a. ty1 -> ty2) In particular, you may need to eta-expand some functions to make typechecking work again. = Furthermore, functions are now invariant in their argument types, rather than being contravariant. Again, the main consequence is that you may occasionally need to eta-expand function arguments when using higher-rank polymorphism. = = Please test, and let me know of any hiccups = = Scoped type variables in GHC ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ January 2006 = 0) Terminology. = A *pattern binding* is of the form pat =3D rhs = A *function binding* is of the form f pat1 .. patn =3D rhs = A binding of the formm var =3D rhs is treated as a (degenerate) *function binding*. = = A *declaration type signature* is a separate type signature for a let-bound or where-bound variable: f :: Int -> Int = A *pattern type signature* is a signature in a pattern: = \(x::a) -> x f (x::a) =3D x = A *result type signature* is a signature on the result of a function definition: f :: forall a. [a] -> a head (x:xs) :: a =3D x = The form x :: a =3D rhs is treated as a (degnerate) function binding with a result type signature, not as a pattern binding. = 1) The main invariants: = A) A lexically-scoped type variable always names a (rigid) type variable (not an arbitrary type). THIS IS A CHANGE. Previously, a scoped type variable named an arbitrary *type*. = B) A type signature always describes a rigid type (since its free (scoped) type variables name rigid type variables). This is also a change, a consequence of (A). = C) Distinct lexically-scoped type variables name distinct rigid type variables. This choice is open; = = 2) Scoping = 2(a) If a declaration type signature has an explicit forall, those type variables are brought into scope in the right hand side of the = corresponding binding (plus, for function bindings, the patterns on the LHS). = f :: forall a. a -> [a] f (x::a) =3D [x :: a, x] Both occurences of 'a' in the second line are bound by = the 'forall a' in the first line = A declaration type signature *without* an explicit top-level forall is implicitly quantified over all the type variables that are mentioned in the type but not already in scope. GHC's current rule is that this implicit quantification does *not* bring into scope any new scoped type variables. f :: a -> a f x =3D ...('a' is not in scope here)... This gives compatibility with Haskell 98 = 2(b) A pattern type signature implicitly brings into scope any type variables mentioned in the type that are not already into scope. These are called *pattern-bound type variables*. g :: a -> a -> [a] g (x::a) (y::a) =3D [y :: a, x] The pattern type signature (x::a) brings 'a' into scope. The 'a' in the pattern (y::a) is bound, as is the occurrence on = the RHS. = = A pattern type siganture is the only way you can bring existentials = into scope. data T where MkT :: forall a. a -> (a->Int) -> T = f x =3D case x of MkT (x::a) f -> f (x::a) = 2a) QUESTION class C a where op :: forall b. b->a->a = instance C (T p q) where op =3D Clearly p,q are in scope in , but is 'b'? Not at the moment. Nor can you add a type signature for op in the instance decl. You'd have to say this: instance C (T p q) where op =3D let op' :: forall b. ... op' =3D in op' = 3) A pattern-bound type variable is allowed only if the pattern's expected type is rigid. Otherwise we don't know exactly *which* skolem the scoped type variable should be bound to, and that means we can't do GADT refinement. This is invariant (A), and it is a = big change from the current situation. = f (x::a) =3D x -- NO; pattern type is wobbly = g1 :: b -> b g1 (x::b) =3D x -- YES, because the pattern type is rigid = g2 :: b -> b g2 (x::c) =3D x -- YES, same reason = h :: forall b. b -> b h (x::b) =3D x -- YES, but the inner b is bound = k :: forall b. b -> b k (x::c) =3D x -- NO, it can't be both b and c = 3a) You cannot give different names for the same type variable in the same= scope (Invariant (C)): = f1 :: p -> p -> p -- NO; because 'a' and 'b' would be f1 (x::a) (y::b) =3D (x::a) -- bound to the same type variable = f2 :: p -> p -> p -- OK; 'a' is bound to the type variable f2 (x::a) (y::a) =3D (x::a) -- over which f2 is quantified -- NB: 'p' is not lexically scoped = f3 :: forall p. p -> p -> p -- NO: 'p' is now scoped, and is bound to f3 (x::a) (y::a) =3D (x::a) -- to the same type varialble as 'a' = f4 :: forall p. p -> p -> p -- OK: 'p' is now scoped, and its occurences f4 (x::p) (y::p) =3D (x::p) -- in the patterns are bound by the foral= l = = 3b) You can give a different name to the same type variable in different disjoint scopes, just as you can (if you want) give diferent names to = the same value parameter = g :: a -> Bool -> Maybe a g (x::p) True =3D Just x :: Maybe p g (y::q) False =3D Nothing :: Maybe q = 3c) Scoped type variables respect alpha renaming. For example, = function f2 from (3a) above could also be written: f2' :: p -> p -> p f2' (x::b) (y::b) =3D x::b where the scoped type variable is called 'b' instead of 'a'. = = 4) Result type signatures obey the same rules as pattern types signatures. In particular, they can bind a type variable only if the result type is= rigid = f x :: a =3D x -- NO = g :: b -> b g x :: b =3D x -- YES; binds b in rhs = 5) A *pattern type signature* in a *pattern binding* cannot bind a = scoped type variable = (x::a, y) =3D ... -- Legal only if 'a' is already in scope = Reason: in type checking, the "expected type" of the LHS pattern is always wobbly, so we can't bind a rigid type variable. (The exception would be for an existential type variable, but existentials are not allowed in pattern bindings either.) = Even this is illegal f :: forall a. a -> a f x =3D let ((y::b)::a, z) =3D ... = in = Here it looks as if 'b' might get a rigid binding; but you can't bind it to the same skolem as a. = 6) Explicitly-forall'd type variables in the *declaration type signature(s= )* for a *pattern binding* do not scope AT ALL. = x :: forall a. a->a -- NO; the forall a does = Just (x::a->a) =3D Just id -- not scope at all = y :: forall a. a->a Just y =3D Just (id :: a->a) -- NO; same reason = THIS IS A CHANGE, but one I bet that very few people will notice. Here's why: = strange :: forall b. (b->b,b->b) strange =3D (id,id) = x1 :: forall a. a->a y1 :: forall b. b->b (x1,y1) =3D strange = This is legal Haskell 98 (modulo the forall). If both 'a' and 'b' both scoped over the RHS, they'd get unified and so cannot stand for distinct type variables. One could *imagine* allowing this: = x2 :: forall a. a->a y2 :: forall a. a->a (x2,y2) =3D strange = using the very same type variable 'a' in both signatures, so that a single 'a' scopes over the RHS. That seems defensible, but odd, because though there are two type signatures, they introduce just *one* scoped type variable, a. = 7) Possible extension. We might consider allowing \(x :: [ _ ]) -> where "_" is a wild card, to mean "x has type list of something", with= out naming the something. = ] = [add double colon and double arrow symbols (-fglasgow-exts) Simon Marlow **20060125135501] = [Fix conDeclFVs for GADTs, to fix bogus unused-import warning simonpj@microsoft.com**20060125090957] = [make the par# primop actually do something Simon Marlow **20060124162521] = [Update Cachegrind support for changes to the Valgrind CLI Simon Marlow **20060124154732] = [send usage info to stdout, not stderr Simon Marlow **20060124145551] = [primop-docs Dinko Tenev **20060122222446] = [remove old CVS stuff, replace with darcs Simon Marlow **20060120151322] = [implement clean/dirty TSOs Simon Marlow **20060123164930 Along the lines of the clean/dirty arrays and IORefs implemented recently, now threads are marked clean or dirty depending on whether they need to be scanned during a minor GC or not. This should speed up GC when there are lots of threads, especially if most of them are idle. ] = [Better error message for Template Haskell pattern brackets simonpj@microsoft.com**20060123142838] = [remove old comment Simon Marlow **20060123140530] = [Fix for feature request #655 (Loading the GHC library from GHCi.) Lemmih **20060123110625 Moved the utility functions out of hschooks, avoided linking the GHC library with hschooks.o and added a couple of symbols to the linkers export list. ] = [Make hsc2hs emit the full path name in {-# LINE #-} pagmas. Duncan Coutts **20060122011831 For one thing this is the right thing to do anyway, it's what other tools = do. Secondly it allows haddock to produce accurate source code links. ] = [MFLAGS +=3D -f Makefile Simon Marlow **20060123094837 merged from CVS, because Tailor isn't merging the libraries subdir ] = [undo accidental commit of snapshot version Simon Marlow **20060122175817] = [TAG final switch to darcs, this repo is now live Simon Marlow **20060120134630] = Patch bundle hash: b7e8acf56fda5cea43a8e6f972783849e82963ab --=_-- .