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* Reorganisation of the source treeSimon Marlow2006-04-071-622/+0
| | | | | | | | | | | | | | | 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.
* Record the type in TuplePat (necessary for GADTs)simonpj@microsoft.com2006-02-021-1/+1
| | | | | | | We must record the type of a TuplePat after typechecking, just like a ConPatOut, so that desugaring works correctly for GADTs. See comments with the declaration of HsPat.TuplePat, and test gadt15
* Simon's big boxy-type commitsimonpj@microsoft.com2006-01-251-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 = rhs A *function binding* is of the form f pat1 .. patn = rhs A binding of the formm var = 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) = x A *result type signature* is a signature on the result of a function definition: f :: forall a. [a] -> a head (x:xs) :: a = x The form x :: a = 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) = [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 = ...('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) = [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 = 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 = <rhs> Clearly p,q are in scope in <rhs>, 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 = let op' :: forall b. ... op' = <rhs> 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) = x -- NO; pattern type is wobbly g1 :: b -> b g1 (x::b) = x -- YES, because the pattern type is rigid g2 :: b -> b g2 (x::c) = x -- YES, same reason h :: forall b. b -> b h (x::b) = x -- YES, but the inner b is bound k :: forall b. b -> b k (x::c) = 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) = (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) = (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) = (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) = (x::p) -- in the patterns are bound by the forall 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 = Just x :: Maybe p g (y::q) False = 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) = 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 = x -- NO g :: b -> b g x :: b = x -- YES; binds b in rhs 5) A *pattern type signature* in a *pattern binding* cannot bind a scoped type variable (x::a, y) = ... -- 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 = let ((y::b)::a, z) = ... 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) = Just id -- not scope at all y :: forall a. a->a Just y = 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 = (id,id) x1 :: forall a. a->a y1 :: forall b. b->b (x1,y1) = 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) = 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 :: [ _ ]) -> <expr> where "_" is a wild card, to mean "x has type list of something", without naming the something.
* [project @ 2006-01-06 16:30:17 by simonmar]simonmar2006-01-061-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add support for UTF-8 source files GHC finally has support for full Unicode in source files. Source files are now assumed to be UTF-8 encoded, and the full range of Unicode characters can be used, with classifications recognised using the implementation from Data.Char. This incedentally means that only the stage2 compiler will recognise Unicode in source files, because I was too lazy to port the unicode classifier code into libcompat. Additionally, the following synonyms for keywords are now recognised: forall symbol (U+2200) forall right arrow (U+2192) -> left arrow (U+2190) <- horizontal ellipsis (U+22EF) .. there are probably more things we could add here. This will break some source files if Latin-1 characters are being used. In most cases this should result in a UTF-8 decoding error. Later on if we want to support more encodings (perhaps with a pragma to specify the encoding), I plan to do it by recoding into UTF-8 before parsing. Internally, there were some pretty big changes: - FastStrings are now stored in UTF-8 - Z-encoding has been moved right to the back end. Previously we used to Z-encode every identifier on the way in for simplicity, and only decode when we needed to show something to the user. Instead, we now keep every string in its UTF-8 encoding, and Z-encode right before printing it out. To avoid Z-encoding the same string multiple times, the Z-encoding is cached inside the FastString the first time it is requested. This speeds up the compiler - I've measured some definite improvement in parsing at least, and I expect compilations overall to be faster too. It also cleans up a lot of cruft from the OccName interface. Z-encoding is nicely hidden inside the Outputable instance for Names & OccNames now. - StringBuffers are UTF-8 too, and are now represented as ForeignPtrs. - I've put together some test cases, not by any means exhaustive, but there are some interesting UTF-8 decoding error cases that aren't obvious. Also, take a look at unicode001.hs for a demo.
* [project @ 2005-11-30 14:20:06 by simonpj]simonpj2005-11-301-19/+63
| | | | | | | | | | | | | | | | ----------------------------------------- Fix 'mkName' operator in Template Haskell so that it handles built-in syntax ----------------------------------------- Merge to stable branch The 'mkName' function in Template Haskell wasn't dealing correctly with built-in syntax. The parser generates Exact RdrNames for built-in syntax operators, such as ':' and '[]'; and hence so should Convert. At the same time I'm now generating a better error message in TH when you use a constructor as a variable or vice versa.
* [project @ 2005-11-12 21:41:12 by simonpj]simonpj2005-11-121-285/+409
| | | | | | | | | | | | | | Better TH -> HsSyn conversion Merge to stable (attempt) This commit monad-ises the TH syntax -> HS syntax conversion. This means that error messages can be reported in a more civilised way. It also ensures that the entire structure is converted eagerly. That means that any exceptions buried inside it are triggered during conversion, and caught by the exception handler in TcSplice. Before, they could be triggered later, and looked like comiler crashes.
* [project @ 2005-10-27 14:35:20 by simonpj]simonpj2005-10-271-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a new pragma: SPECIALISE INLINE This amounts to adding an INLINE pragma to the specialised version of the function. You can add phase stuff too (SPECIALISE INLINE [2]), and NOINLINE instead of INLINE. The reason for doing this is to support inlining of type-directed recursive functions. The main example is this: -- non-uniform array type data Arr e where ArrInt :: !Int -> ByteArray# -> Arr Int ArrPair :: !Int -> Arr e1 -> Arr e2 -> Arr (e1, e2) (!:) :: Arr e -> Int -> e {-# SPECIALISE INLINE (!:) :: Arr Int -> Int -> Int #-} {-# SPECIALISE INLINE (!:) :: Arr (a, b) -> Int -> (a, b) #-} ArrInt _ ba !: (I# i) = I# (indexIntArray# ba i) ArrPair _ a1 a2 !: i = (a1 !: i, a2 !: i) If we use (!:) at a particular array type, we want to inline (:!), which is recursive, until all the type specialisation is done. On the way I did a bit of renaming and tidying of the way that pragmas are carried, so quite a lot of files are touched in a fairly trivial way.
* [project @ 2005-10-17 11:11:15 by simonpj]simonpj2005-10-171-8/+9
| | | | Buglets in GADT record-syntax stuff, which killed the weekend builds
* [project @ 2005-07-19 16:44:50 by simonpj]simonpj2005-07-191-7/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | WARNING: this is a big commit. You might want to wait a few days before updating, in case I've broken something. However, if any of the changes are what you wanted, please check it out and test! This commit does three main things: 1. A re-organisation of the way that GHC handles bindings in HsSyn. This has been a bit of a mess for quite a while. The key new types are -- Bindings for a let or where clause data HsLocalBinds id = HsValBinds (HsValBinds id) | HsIPBinds (HsIPBinds id) | EmptyLocalBinds -- Value bindings (not implicit parameters) data HsValBinds id = ValBindsIn -- Before typechecking (LHsBinds id) [LSig id] -- Not dependency analysed -- Recursive by default | ValBindsOut -- After typechecking [(RecFlag, LHsBinds id)]-- Dependency analysed 2. Implement Mark Jones's idea of increasing polymoprhism by using type signatures to cut the strongly-connected components of a recursive group. As a consequence, GHC no longer insists on the contexts of the type signatures of a recursive group being identical. This drove a significant change: the renamer no longer does dependency analysis. Instead, it attaches a free-variable set to each binding, so that the type checker can do the dep anal. Reason: the typechecker needs to do *two* analyses: one to find the true mutually-recursive groups (which we need so we can build the right CoreSyn) one to find the groups in which to typecheck, taking account of type signatures 3. Implement non-ground SPECIALISE pragmas, as promised, and as requested by Remi and Ross. Certainly, this should fix the current problem with GHC, namely that if you have g :: Eq a => a -> b -> b then you can now specialise thus SPECIALISE g :: Int -> b -> b (This didn't use to work.) However, it goes further than that. For example: f :: (Eq a, Ix b) => a -> b -> b then you can make a partial specialisation SPECIALISE f :: (Eq a) => a -> Int -> Int In principle, you can specialise f to *any* type that is "less polymorphic" (in the sense of subsumption) than f's actual type. Such as SPECIALISE f :: Eq a => [a] -> Int -> Int But I haven't tested that. I implemented this by doing the specialisation in the typechecker and desugarer, rather than leaving around the strange SpecPragmaIds, for the specialiser to find. Indeed, SpecPragmaIds have vanished altogether (hooray). Pragmas in general are handled more tidily. There's a new data type HsBinds.Prag, which lives in an AbsBinds, and carries pragma info from the typechecker to the desugarer. Smaller things - The loop in the renamer goes via RnExpr, instead of RnSource. (That makes it more like the type checker.) - I fixed the thing that was causing 'check_tc' warnings to be emitted.
* [project @ 2005-07-12 16:30:01 by simonpj]simonpj2005-07-121-185/+181
| | | | | | | | | | | Try MERGE to STABLE When TH splices in code, it was previously decorated with noLoc. If there were any type errors in it, we got a very unhelpful message. Now we propagate the splice location everywhere into the spliced code. The location isn't very exact, because it refers to the splice site, but it's better than before.
* [project @ 2005-04-04 16:49:42 by simonpj]simonpj2005-04-041-4/+4
| | | | One more stage2 wibble
* [project @ 2005-04-04 11:55:11 by simonpj]simonpj2005-04-041-20/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 do-notation. 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.)
* [project @ 2005-01-31 15:48:13 by simonpj]simonpj2005-01-311-10/+18
| | | | | | | | | | | | | | --------------------------- Some Template Haskell fixes --------------------------- * Tidy up conversion from TH.Name to RdrName.RdrName. It was partly duplicated between Convert.thRdrName and TcSplice.lookupThName. Now it's all in one place: Convert.thRdrName * Fix a bug in TH.tupleTypeName/TH.tupleDataName (GHC.Tuple -> Data.Tuple) * Export appEs from Language.Haskell.TH
* [project @ 2004-12-23 09:07:30 by simonpj]simonpj2004-12-231-4/+10
| | | | | | | | | | | | | | | | | | | | | | --------------------------------- Template Haskell: names again --------------------------------- On 2 Dec 04 I made this commit (1.58 in Convert.lhs) Fix a Template Haskell bug that meant that top-level names created with newName were not made properly unique. But that just introduced a new bug! THe trouble is that names created by newName are NameUs; but I was *also* using NameU for names of free varaibles, such as the 'x' in the quoted code here f x = $( g [| \y -> (x,y) |]) But when converting to HsSyn, the x and y must be treated diffferently. The 'x' must convert to an Exact RdrName, so that it binds to the 'x' that's in the type environment; but the 'y' must generate a nice unique RdrName. So this commit adds NameL for the lexically-scoped bindings like 'x'.
* [project @ 2004-12-21 17:08:59 by simonpj]simonpj2004-12-211-19/+3
| | | | | | | | | | | | | | | --------------------------------- Template Haskell: dynamically scoped qualified names --------------------------------- This commit adds a constructor to TH.Name, so that nameBase (mkName "Foo.baz") == "baz" nameModule (MkName "Foo.baz") == "Foo" We always did parse the module name off the front, but it used to be done in hsSyn/Convert, but now it's done in TH.Syntax, which is a better place.
* [project @ 2004-12-02 17:18:15 by simonpj]simonpj2004-12-021-23/+23
| | | | | | | | | | | | Sorry for the fact that there are overlapping three commits in here... 1. Make -fno-monomorphism-restriction and -fno-implicit-prelude reversible, like other flags 2. Fix a wibble in the new ImportAvails story, in RnNames.mkExportAvails 3. Fix a Template Haskell bug that meant that top-level names created with newName were not made properly unique.
* [project @ 2004-11-26 16:19:45 by simonmar]simonmar2004-11-261-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Further integration with the new package story. GHC now supports pretty much everything in the package proposal. - GHC now works in terms of PackageIds (<pkg>-<version>) rather than just package names. You can still specify package names without versions on the command line, as long as the name is unambiguous. - GHC understands hidden/exposed modules in a package, and will refuse to import a hidden module. Also, the hidden/eposed status of packages is taken into account. - I had to remove the old package syntax from ghc-pkg, backwards compatibility isn't really practical. - All the package.conf.in files have been rewritten in the new syntax, and contain a complete list of modules in the package. I've set all the versions to 1.0 for now - please check your package(s) and fix the version number & other info appropriately. - New options: -hide-package P sets the expose flag on package P to False -ignore-package P unregisters P for this compilation For comparison, -package P sets the expose flag on package P to True, and also causes P to be linked in eagerly. -package-name is no longer officially supported. Unofficially, it's a synonym for -ignore-package, which has more or less the same effect as -package-name used to. Note that a package may be hidden and yet still be linked into the program, by virtue of being a dependency of some other package. To completely remove a package from the compiler's internal database, use -ignore-package. The compiler will complain if any two packages in the transitive closure of exposed packages contain the same module. You *must* use -ignore-package P when compiling modules for package P, if package P (or an older version of P) is already registered. The compiler will helpfully complain if you don't. The fptools build system does this. - Note: the Cabal library won't work yet. It still thinks GHC uses the old package config syntax. Internal changes/cleanups: - The ModuleName type has gone away. Modules are now just (a newtype of) FastStrings, and don't contain any package information. All the package-related knowledge is in DynFlags, which is passed down to where it is needed. - DynFlags manipulation has been cleaned up somewhat: there are no global variables holding DynFlags any more, instead the DynFlags are passed around properly. - There are a few less global variables in GHC. Lots more are scheduled for removal. - -i is now a dynamic flag, as are all the package-related flags (but using them in {-# OPTIONS #-} is Officially Not Recommended). - make -j now appears to work under fptools/libraries/. Probably wouldn't take much to get it working for a whole build.
* [project @ 2004-11-18 00:56:18 by igloo]igloo2004-11-181-5/+11
| | | | Implement FunDeps for TH.
* [project @ 2004-11-03 01:10:53 by igloo]igloo2004-11-031-2/+9
| | | | Implement TH ForallC constructor.
* [project @ 2004-10-08 11:37:46 by simonpj]simonpj2004-10-081-2/+2
| | | | HsNoBang should simply be omitted; fixes a TH_spliceDecl2 test
* [project @ 2004-10-01 16:39:26 by simonpj]simonpj2004-10-011-4/+4
| | | | Allow kind signatures in GADT data type declarations
* [project @ 2004-09-30 10:35:15 by simonpj]simonpj2004-09-301-11/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ------------------------------------ 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).
* [project @ 2004-06-01 23:22:30 by igloo]igloo2004-06-011-4/+8
| | | | | | | | | | | | | | | | Add missing functions to TH export list (mostly spotted by Duncan Coutts). Update TH test output. Add TH support for patterns with type signatures, and test for same (requested by Isaac Jones). Add TH support for pattern guards, and tests for same (requested by Isaac Jones). Add infix patterns to TH datatypes. Added Lift instances for 2- to 7-tuples (requested by Duncan Coutts).
* [project @ 2004-04-21 12:38:20 by simonpj]simonpj2004-04-211-1/+18
| | | | | | | In Template Haskell suppport dyn "M.x" to mean "look up the qualified name M.x in the environment", which is what you'd expect. George Russel wanted this.
* [project @ 2004-04-05 10:52:23 by simonpj]simonpj2004-04-051-5/+5
| | | | | | | | | Remove the entirely-redundant location from the argument of constructor HsPredTy, so that we have HsPredTy HsType rather than HsPredTy LHsType
* [project @ 2004-04-02 16:54:02 by simonpj]simonpj2004-04-021-1/+1
| | | | Another stage-2 wibble to last commit
* [project @ 2004-03-17 13:59:06 by simonpj]simonpj2004-03-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | ------------------------ More newtype clearing up ------------------------ * Change the representation of TyCons so that it accurately reflects * data (0 or more constrs) * newtype (1 constr) * abstract (unknown) Replaces DataConDetails and AlgTyConFlavour with AlgTyConRhs * Add IfaceSyn.IfaceConDecls, a kind of stripped-down analogue of AlgTyConRhs * Move NewOrData from BasicTypes to HsDecl (it's now an HsSyn thing) * Arrange that Type.newTypeRep and splitRecNewType_maybe unwrap just one layer of new-type-ness, leaving the caller to recurse. This still leaves typeRep and repType in Type.lhs; these functions are still vaguely disturbing and probably should get some attention. Lots of knock-on changes. Fixes bug in ds054.
* [project @ 2004-01-05 15:15:26 by igloo]igloo2004-01-051-2/+2
| | | | | | Use pprint rather than show . ppr to get String representations of TH datastructures. Also moved pprint out of the class as we never want to override it.
* [project @ 2004-01-05 09:35:00 by simonpj]simonpj2004-01-051-2/+2
| | | | Pretty-print wibbles following Ians changes to TH libs
* [project @ 2004-01-04 01:48:04 by igloo]igloo2004-01-041-2/+2
| | | | | | | | | | Split the pretty-printer out - pprint will now give you pretty much anything you are likely to want to pretty-print as a String. For a Doc you need (to_HPJ_Doc . ppr), which could be made nicer if it is widely used. Also took the opportunity to do a bit of module renaming and fixed the odd typo here and there.
* [project @ 2003-12-16 16:24:55 by simonpj]simonpj2003-12-161-10/+11
| | | | | | | | | | -------------------- Towards type splices -------------------- Starts the move to supporting type splices, by making HsExpr.HsSplice a separate type of its own, and adding HsSpliceTy constructor to HsType.
* [project @ 2003-12-10 14:15:16 by simonmar]simonmar2003-12-101-120/+120
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 spot-on. 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. Implementation: 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.
* [project @ 2003-11-06 17:09:50 by simonpj]simonpj2003-11-061-74/+79
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ------------------------------------ Major increment for Template Haskell ------------------------------------ 1. New abstract data type "Name" which appears where String used to be. E.g. data Exp = VarE Name | ... 2. New syntax 'x and ''T, for quoting Names. It's rather like [| x |] and [t| T |] respectively, except that a) it's non-monadic: 'x :: Name b) you get a Name not an Exp or Type 3. reify is an ordinary function reify :: Name -> Q Info New data type Info which tells what TH knows about Name 4. Local variables work properly. So this works now (crashed before): f x = $( [| x |] ) 5. THSyntax is split up into three modules: Language.Haskell.TH TH "clients" import this Language.Haskell.TH.THSyntax data type declarations and internal stuff Language.Haskell.TH.THLib Support library code (all re-exported by TH), including smart constructors and pretty printer 6. Error reporting and recovery are in (not yet well tested) report :: Bool {- True <=> fatal -} -> String -> Q () recover :: Q a -> Q a -> Q a 7. Can find current module currentModule :: Q String Much other cleaning up, needless to say.
* [project @ 2003-10-31 12:57:59 by simonpj]simonpj2003-10-311-2/+10
| | | | Wibble to TH -> HsSyn conversion
* [project @ 2003-10-30 10:12:39 by simonpj]simonpj2003-10-301-1/+1
| | | | Wibble
* [project @ 2003-10-30 09:38:14 by simonpj]simonpj2003-10-301-1/+1
| | | | Improve panic msg
* [project @ 2003-10-23 11:24:43 by simonpj]simonpj2003-10-231-1/+1
| | | | Another HsForAllTy wibble
* [project @ 2003-10-21 12:54:17 by simonpj]simonpj2003-10-211-7/+4
| | | | | | | | | | 1. A tiresome change to HsType, to keep a record of whether or not the HsForAll was originally explicitly-quantified. This is solely so that the type checker can print out messages that show the source code the programmer wrote. Tiresome but easy. 2. Improve reporting of kind errors.
* [project @ 2003-10-09 11:58:39 by simonpj]simonpj2003-10-091-14/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ------------------------- 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
* [project @ 2003-08-15 15:53:00 by igloo]igloo2003-08-151-2/+11
| | | | Add support for splicing in foreign exports.
* [project @ 2003-06-24 07:58:18 by simonpj]simonpj2003-06-241-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ---------------------------------------------- Add support for Ross Paterson's arrow notation ---------------------------------------------- Ross Paterson's ICFP'01 paper described syntax to support John Hughes's "arrows", rather as do-notation supports monads. Except that do-notation is relatively modest -- you can write monads by hand without much trouble -- whereas arrow-notation is more-or-less essential for writing arrow programs. It desugars to a massive pile of tuple construction and selection! For some time, Ross has had a pre-processor for arrow notation, but the resulting type error messages (reported in terms of the desugared code) are impenetrable. This commit integrates the syntax into GHC. The type error messages almost certainly still require tuning, but they should be better than with the pre-processor. Main syntactic changes (enabled with -farrows) exp ::= ... | proc pat -> cmd cmd ::= exp1 -< exp2 | exp1 >- exp2 | exp1 -<< exp2 | exp1 >>- exp2 | \ pat1 .. patn -> cmd | let decls in cmd | if exp then cmd1 else cmd2 | do { cstmt1 .. cstmtn ; cmd } | (| exp |) cmd1 .. cmdn | cmd1 qop cmd2 | case exp of { calts } cstmt :: = let decls | pat <- cmd | rec { cstmt1 .. cstmtn } | cmd New keywords and symbols: proc rec -< >- -<< >>- (| |) The do-notation in cmds was not described in Ross's ICFP'01 paper; instead it's in his chapter in The Fun of Programming (Plagrave 2003). The four arrow-tail forms (-<) etc cover (a) which order the pices come in (-< vs >-), and (b) whether the locally bound variables can be used in the arrow part (-< vs -<<) . In previous presentations, the higher-order-ness (b) was inferred, but it makes a big difference to the typing required so it seems more consistent to be explicit. The 'rec' form is also available in do-notation: * you can use 'rec' in an ordinary do, with the obvious meaning * using 'mdo' just says "infer the minimal recs" Still to do ~~~~~~~~~~~ Top priority is the user manual. The implementation still lacks an implementation of the case form of cmd. Implementation notes ~~~~~~~~~~~~~~~~~~~~ Cmds are parsed, and indeed renamed, as expressions. The type checker distinguishes the two.
* [project @ 2003-06-08 18:12:23 by igloo]igloo2003-06-081-0/+1
| | | | | | | Introduce a ListP for consistency with ListE. Splicing in something with a list pattern now works too. Added various list tests.
* [project @ 2003-06-06 16:04:23 by igloo]igloo2003-06-061-91/+87
| | | | | Template Haskell Renamings as described in http://www.haskell.org/pipermail/template-haskell/2003-May/000110.html
* [project @ 2003-05-21 18:07:13 by igloo]igloo2003-05-211-89/+90
| | | | | | | | | | | The Great Renaming. I hope I've kept everything in sync - and all the tests pass. Now datatypes follow the data Foo = <a kind of Foo>Foo | <another kind of Foo>Foo convention and the smart constructors can be uniformly created by lowercasing the first letter of the constructor.
* [project @ 2003-05-21 02:58:39 by igloo]igloo2003-05-211-20/+26
| | | | Added support for newtypes to TH and altered a test for them.
* [project @ 2003-05-19 15:10:40 by simonpj]simonpj2003-05-191-2/+2
| | | | | | | | | | | -------------------------- Minor Template Haskell bug -------------------------- This bug meant that spliced-in class declarations yielded a 'op not in scope', where op was the class operation. Thanks to Andre Pang for spotting this. Some consequential tidying up in parsing too.
* [project @ 2003-05-04 13:21:48 by igloo]igloo2003-05-041-2/+5
| | | | Add support for unboxed Ints, Floats and Doubles to Template Haskell.
* [project @ 2003-04-25 20:58:09 by panne]panne2003-04-251-3/+3
| | | | Unbreak 2nd stage
* [project @ 2003-04-22 20:39:59 by igloo]igloo2003-04-221-6/+6
| | | | | | | | Order declarations in reifications in order of source line number. The bugs still there but it bites less often now... Also remove the type parameterisation and do some type renaming as discussed on the template-haskell list.
* [project @ 2003-03-16 14:15:21 by igloo]igloo2003-03-161-3/+6
| | | | Support for contexts on data types and records from Derek Elkins.
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