| Commit message (Collapse) | Author | Age | Files | Lines |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This patch completely re-engineers how we deal with loopy superclass
dictionaries in instance declarations. It fixes #20666 and #19690
The highlights are
* Recognise that the loopy-superclass business should use precisely
the Paterson conditions. This is much much nicer. See
Note [Recursive superclasses] in GHC.Tc.TyCl.Instance
* With that in mind, define "Paterson-smaller" in
Note [Paterson conditions] in GHC.Tc.Validity, and the new
data type `PatersonSize` in GHC.Tc.Utils.TcType, along with
functions to compute and compare PatsonSizes
* Use the new PatersonSize stuff when solving superclass constraints
See Note [Solving superclass constraints] in GHC.Tc.TyCl.Instance
* In GHC.Tc.Solver.Monad.lookupInInerts, add a missing call to
prohibitedSuperClassSolve. This was the original cause of #20666.
* Treat (TypeError "stuff") as having PatersonSize zero. See
Note [Paterson size for type family applications] in GHC.Tc.Utils.TcType.
* Treat the head of a Wanted quantified constraint in the same way
as the superclass of an instance decl; this is what fixes #19690.
See GHC.Tc.Solver.Canonical Note [Solving a Wanted forall-constraint]
(Thanks to Matthew Craven for this insight.)
This entailed refactoring the GivenSc constructor of CtOrigin a bit,
to say whether it comes from an instance decl or quantified constraint.
* Some refactoring way in which redundant constraints are reported; we
don't want to complain about the extra, apparently-redundant
constraints that we must add to an instance decl because of the
loopy-superclass thing. I moved some work from GHC.Tc.Errors to
GHC.Tc.Solver.
* Add a new section to the user manual to describe the loopy
superclass issue and what rules it follows.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
GHC Proposals #448 "Modern scoped type variables"
and #425 "Invisible binders in type declarations"
introduce a new language extension flag: TypeAbstractions.
Part of the functionality guarded by this flag has already been
implemented, namely type abstractions in constructor patterns, but it
was guarded by a combination of TypeApplications and ScopedTypeVariables
instead of a dedicated language extension flag.
This patch does the following:
* introduces a new language extension flag TypeAbstractions
* requires TypeAbstractions for @a-syntax in constructor patterns
instead of TypeApplications and ScopedTypeVariables
* creates a User's Guide page for TypeAbstractions and
moves the "Type Applications in Patterns" section there
To avoid a breaking change, the new flag is implied by
ScopedTypeVariables and is retroactively added to GHC2021.
Metric Decrease:
MultiLayerModulesTH_OneShot
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This implements proposal 547 and closes ticket #22298.
See the proposal and ticket for motivation.
Compiler perf improves a bit
Metrics: compile_time/bytes allocated
-------------------------------------
CoOpt_Singletons(normal) -2.4% GOOD
T12545(normal) +1.0%
T13035(normal) -13.5% GOOD
T18478(normal) +0.9%
T9872d(normal) -2.2% GOOD
geo. mean -0.2%
minimum -13.5%
maximum +1.0%
Metric Decrease:
CoOpt_Singletons
T13035
T9872d
|
|
|
|
| |
This simple patch fixes #22647
|
|
|
|
|
|
|
| |
The old assertion saw that a constraint ct could rewrite itself
(of course it can) and complained (stupid).
Fixes #22645
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Previously, the `checkValidInst` function (used when checking that an instance
declaration is headed by an actual type class, not a type synonym) was using
`tcSplitSigmaTy` to split apart the `forall`s and instance context. This is
incorrect, however, as `tcSplitSigmaTy` expands type synonyms, which can cause
instances headed by quantified constraint type synonyms to be accepted
erroneously.
This patch introduces `splitInstTyForValidity`, a variant of `tcSplitSigmaTy`
specialized for validity checking that does _not_ expand type synonyms, and
uses it in `checkValidInst`.
Fixes #22570.
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
There was some confusion in Data.Typeable about which module certain
wired-in things were defined in. Just because something is wired-in
doesn't mean it comes from GHC.Prim, in particular things like LiftedRep
and RuntimeRep are defined in GHC.Types and that's the end of the story.
Things like Int#, Float# etc are defined in GHC.Prim as they have no
Haskell definition site at all so we need to generate type
representations for them (which live in GHC.Types).
Fixes #22510
|
| |
|
|
|
|
|
|
|
|
|
| |
The Show instance for TypeRep [] has changed in 9.5 to output "List"
because the name of the type constructor changed.
This seems to be accidental and is inconsistent with TypeReps of saturated
lists, which are printed as e.g. "[Int]".
For now, I'm restoring the old behavior; in the future,
maybe we should show TypeReps without puns (List, Tuple, Type).
|
|
|
|
|
|
|
|
| |
We were failing to account for the cc_pend_sc flag in this
important function, with the result that we expanded superclasses
forever.
Fixes #22516.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Add JS backend adapted from the GHCJS project by Luite Stegeman.
Some features haven't been ported or implemented yet. Tests for these
features have been disabled with an associated gitlab ticket.
Bump array submodule
Work funded by IOG.
Co-authored-by: Jeffrey Young <jeffrey.young@iohk.io>
Co-authored-by: Luite Stegeman <stegeman@gmail.com>
Co-authored-by: Josh Meredith <joshmeredith2008@gmail.com>
|
|
|
|
|
|
|
|
| |
Literals in Core were printed as e.g. 0xFF#16 :: Int16#.
The proposal 451 now specifies syntax 0xFF#Int16.
This change affects the Core printer only - more to be done later.
Part of #21422.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
equality processing order
Fixes: #217093
Associated to #19415
This change
* Flips the orientation of the the generated kind equality coercion in canEqLHSHetero;
* Removes `cc_fundeps` in CDictCan as the check was incomplete;
* Changes `canDecomposableTyConAppOk` to ensure we process kind equalities before type equalities and avoiding a call to `canEqLHSHetero` while processing wanted TyConApp equalities
* Adds 2 new tests for validating the change
- testsuites/typecheck/should_compile/T21703.hs and
- testsuites/typecheck/should_fail/T19415b.hs (a simpler version of T19415.hs)
* Misc: Due to the change in the equality direction some error messages now have flipped type mismatch errors
* Changes in Notes:
- Note [Fundeps with instances, and equality orientation] supercedes Note [Fundeps with instances]
- Added Note [Kind Equality Orientation] to visualize the kind flipping
- Added Note [Decomposing Dependent TyCons and Processing Wanted Equalties]
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Ticket #22331 showed that we were being too eager to decompose
a Wanted TyConApp, leading to incompleteness in the solver.
To understand all this I ended up doing a substantial rewrite
of the old Note [Decomposing equalities], now reborn as
Note [Decomposing TyConApp equalities]. Plus rewrites of other
related Notes.
The actual fix is very minor and actually simplifies the code: in
`can_decompose` in `GHC.Tc.Solver.Canonical.canTyConApp`, we now call
`noMatchableIrreds`. A closely related refactor: we stop trying to
use the same "no matchable givens" function here as in
`matchClassInst`. Instead split into two much simpler functions.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Before this patch, GHC unconditionally printed ticks before promoted
data constructors:
ghci> type T = True -- unticked (user-written)
ghci> :kind! T
T :: Bool
= 'True -- ticked (compiler output)
After this patch, GHC prints ticks only when necessary:
ghci> type F = False -- unticked (user-written)
ghci> :kind! F
F :: Bool
= False -- unticked (compiler output)
ghci> data False -- introduce ambiguity
ghci> :kind! F
F :: Bool
= 'False -- ticked by necessity (compiler output)
The old behavior can be enabled by -fprint-redundant-promotion-ticks.
Summary of changes:
* Rename PrintUnqualified to NamePprCtx
* Add QueryPromotionTick to it
* Consult the GlobalRdrEnv to decide whether to print a tick (see mkPromTick)
* Introduce -fprint-redundant-promotion-ticks
Co-authored-by: Artyom Kuznetsov <hi@wzrd.ht>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Problem: avoid usage of TcRnMessageUnknown
Solution:
The following `TcRnMessage` messages has been introduced:
TcRnNoRebindableSyntaxRecordDot
TcRnNoFieldPunsRecordDot
TcRnIllegalStaticExpression
TcRnIllegalStaticFormInSplice
TcRnListComprehensionDuplicateBinding
TcRnEmptyStmtsGroup
TcRnLastStmtNotExpr
TcRnUnexpectedStatementInContext
TcRnIllegalTupleSection
TcRnIllegalImplicitParameterBindings
TcRnSectionWithoutParentheses
Co-authored-by: sheaf <sam.derbyshire@gmail.com>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This big patch addresses the rats-nest of issues that have plagued
us for years, about the relationship between Type and Constraint.
See #11715/#21623.
The main payload of the patch is:
* To introduce CONSTRAINT :: RuntimeRep -> Type
* To make TYPE and CONSTRAINT distinct throughout the compiler
Two overview Notes in GHC.Builtin.Types.Prim
* Note [TYPE and CONSTRAINT]
* Note [Type and Constraint are not apart]
This is the main complication.
The specifics
* New primitive types (GHC.Builtin.Types.Prim)
- CONSTRAINT
- ctArrowTyCon (=>)
- tcArrowTyCon (-=>)
- ccArrowTyCon (==>)
- funTyCon FUN -- Not new
See Note [Function type constructors and FunTy]
and Note [TYPE and CONSTRAINT]
* GHC.Builtin.Types:
- New type Constraint = CONSTRAINT LiftedRep
- I also stopped nonEmptyTyCon being built-in; it only needs to be wired-in
* Exploit the fact that Type and Constraint are distinct throughout GHC
- Get rid of tcView in favour of coreView.
- Many tcXX functions become XX functions.
e.g. tcGetCastedTyVar --> getCastedTyVar
* Kill off Note [ForAllTy and typechecker equality], in (old)
GHC.Tc.Solver.Canonical. It said that typechecker-equality should ignore
the specified/inferred distinction when comparein two ForAllTys. But
that wsa only weakly supported and (worse) implies that we need a separate
typechecker equality, different from core equality. No no no.
* GHC.Core.TyCon: kill off FunTyCon in data TyCon. There was no need for it,
and anyway now we have four of them!
* GHC.Core.TyCo.Rep: add two FunTyFlags to FunCo
See Note [FunCo] in that module.
* GHC.Core.Type. Lots and lots of changes driven by adding CONSTRAINT.
The key new function is sORTKind_maybe; most other changes are built
on top of that.
See also `funTyConAppTy_maybe` and `tyConAppFun_maybe`.
* Fix a longstanding bug in GHC.Core.Type.typeKind, and Core Lint, in
kinding ForAllTys. See new tules (FORALL1) and (FORALL2) in GHC.Core.Type.
(The bug was that before (forall (cv::t1 ~# t2). blah), where
blah::TYPE IntRep, would get kind (TYPE IntRep), but it should be
(TYPE LiftedRep). See Note [Kinding rules for types] in GHC.Core.Type.
* GHC.Core.TyCo.Compare is a new module in which we do eqType and cmpType.
Of course, no tcEqType any more.
* GHC.Core.TyCo.FVs. I moved some free-var-like function into this module:
tyConsOfType, visVarsOfType, and occCheckExpand. Refactoring only.
* GHC.Builtin.Types. Compiletely re-engineer boxingDataCon_maybe to
have one for each /RuntimeRep/, rather than one for each /Type/.
This dramatically widens the range of types we can auto-box.
See Note [Boxing constructors] in GHC.Builtin.Types
The boxing types themselves are declared in library ghc-prim:GHC.Types.
GHC.Core.Make. Re-engineer the treatment of "big" tuples (mkBigCoreVarTup
etc) GHC.Core.Make, so that it auto-boxes unboxed values and (crucially)
types of kind Constraint. That allows the desugaring for arrows to work;
it gathers up free variables (including dictionaries) into tuples.
See Note [Big tuples] in GHC.Core.Make.
There is still work to do here: #22336. But things are better than
before.
* GHC.Core.Make. We need two absent-error Ids, aBSENT_ERROR_ID for types of
kind Type, and aBSENT_CONSTRAINT_ERROR_ID for vaues of kind Constraint.
Ditto noInlineId vs noInlieConstraintId in GHC.Types.Id.Make;
see Note [inlineId magic].
* GHC.Core.TyCo.Rep. Completely refactor the NthCo coercion. It is now called
SelCo, and its fields are much more descriptive than the single Int we used to
have. A great improvement. See Note [SelCo] in GHC.Core.TyCo.Rep.
* GHC.Core.RoughMap.roughMatchTyConName. Collapse TYPE and CONSTRAINT to
a single TyCon, so that the rough-map does not distinguish them.
* GHC.Core.DataCon
- Mainly just improve documentation
* Some significant renamings:
GHC.Core.Multiplicity: Many --> ManyTy (easier to grep for)
One --> OneTy
GHC.Core.TyCo.Rep TyCoBinder --> GHC.Core.Var.PiTyBinder
GHC.Core.Var TyCoVarBinder --> ForAllTyBinder
AnonArgFlag --> FunTyFlag
ArgFlag --> ForAllTyFlag
GHC.Core.TyCon TyConTyCoBinder --> TyConPiTyBinder
Many functions are renamed in consequence
e.g. isinvisibleArgFlag becomes isInvisibleForAllTyFlag, etc
* I refactored FunTyFlag (was AnonArgFlag) into a simple, flat data type
data FunTyFlag
= FTF_T_T -- (->) Type -> Type
| FTF_T_C -- (-=>) Type -> Constraint
| FTF_C_T -- (=>) Constraint -> Type
| FTF_C_C -- (==>) Constraint -> Constraint
* GHC.Tc.Errors.Ppr. Some significant refactoring in the TypeEqMisMatch case
of pprMismatchMsg.
* I made the tyConUnique field of TyCon strict, because I
saw code with lots of silly eval's. That revealed that
GHC.Settings.Constants.mAX_SUM_SIZE can only be 63, because
we pack the sum tag into a 6-bit field. (Lurking bug squashed.)
Fixes
* #21530
Updates haddock submodule slightly.
Performance changes
~~~~~~~~~~~~~~~~~~~
I was worried that compile times would get worse, but after
some careful profiling we are down to a geometric mean 0.1%
increase in allocation (in perf/compiler). That seems fine.
There is a big runtime improvement in T10359
Metric Decrease:
LargeRecord
MultiLayerModulesTH_OneShot
T13386
T13719
Metric Increase:
T8095
|
|
|
|
|
|
|
|
|
|
|
|
| |
The following `TcRnDiagnostic` messages have been introduced:
TcRnWarnUnsatisfiedMinimalDefinition
TcRnMisplacedInstSig
TcRnBadBootFamInstDeclErr
TcRnIllegalFamilyInstance
TcRnAssocInClassErr
TcRnBadFamInstDecl
TcRnNotOpenFamily
|
|
|
|
|
| |
Necessary for newer cross-compiling backends (JS, Wasm) that don't
support TH yet.
|
|
|
|
|
|
|
|
|
|
| |
The assertion that checked TyEq:N in canEqCanLHSFinish incorrectly
triggered in the case of an unsaturated newtype TyCon heading the RHS,
even though we can't unwrap such an application. Now, we only trigger
an assertion failure in case of a saturated application of a newtype
TyCon.
Fixes #22310
|
|
|
|
|
|
|
|
|
|
|
| |
When a newtype introduces GADT eq_specs due to a defaulted
RuntimeRep, we detect this and print the error message with
explicit kinds.
This also refactors newtype type checking to use the new
diagnostic infra.
Fixes #21447
|
|
|
|
|
| |
We want to put implicit binds into fat interface files, so the easiest
thing to do seems to be to treat them uniformly with other binders.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This implements this Core Libraries Proposal:
https://github.com/haskell/core-libraries-committee/issues/85
In particular, it:
1. Exposes the `symbolSing` method of `KnownSymbol`,
2. Exports the abstract `SSymbol` type used in `symbolSing`, and
3. Defines an API for interacting with `SSymbol`.
This also makes corresponding changes for `natSing`/`KnownNat`/`SNat` and
`charSing`/`KnownChar`/`SChar`. This fixes #15183 and addresses part (2)
of #21568.
|
|
|
|
|
|
|
|
|
|
|
| |
Part of proposal 475 (https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0475-tuple-syntax.rst)
Moves all tuples to GHC.Tuple.Prim
Updates ghc-prim version (and bumps bounds in dependents)
updates haddock submodule
updates deepseq submodule
updates text submodule
|
|
|
|
|
|
|
|
| |
Rather than a list of constructors and a `NewOrData` flag, we define `data DataDefnCons a = NewTypeCon a | DataTypeCons [a]`, which enforces a newtype to have exactly one constructor.
Closes #22070.
Bump haddock submodule.
|
|
|
|
|
|
|
|
| |
The testsuite output now contains diagnostic codes, so many tests need
to be updated at once.
We decided it was best to keep the diagnostic codes in the testsuite
output, so that contributors don't inadvertently make changes to the
diagnostic codes.
|
|
|
|
|
| |
This was fixed by ca90ffa321a31842a32be1b5b6e26743cd677ec5
"Use local instances with least superclass depth"
|
|
|
|
|
|
|
|
|
|
|
|
| |
The following `TcRnDiagnostic` messages have been introduced:
TcRnIllegalHsigDefaultMethods
TcRnBadGenericMethod
TcRnWarningMinimalDefIncomplete
TcRnDefaultMethodForPragmaLacksBinding
TcRnIgnoreSpecialisePragmaOnDefMethod
TcRnBadMethodErr
TcRnNoExplicitAssocTypeOrDefaultDeclaration
|
|
|
|
|
|
|
| |
This patch improves the uniformity of error message formatting by
printing constraints in quotes, as we do for types.
Fix #21167
|
| |
|
| |
|
|
|
|
| |
Fixes #21866
|
| |
|
| |
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This MR adds the language extension -XDeepSubsumption, implementing
GHC proposal #511. This change mitigates the impact of GHC proposal
The changes are highly localised, by design. See Note [Deep subsumption]
in GHC.Tc.Utils.Unify.
The main changes are:
* Add -XDeepSubsumption, which is on by default in Haskell98 and Haskell2010,
but off in Haskell2021.
-XDeepSubsumption largely restores the behaviour before the "simple subsumption" change.
-XDeepSubsumpition has a similar flavour as -XNoMonoLocalBinds:
it makes type inference more complicated and less predictable, but it
may be convenient in practice.
* The main changes are in:
* GHC.Tc.Utils.Unify.tcSubType, which does deep susumption and eta-expanansion
* GHC.Tc.Utils.Unify.tcSkolemiseET, which does deep skolemisation
* In GHC.Tc.Gen.App.tcApp we call tcSubTypeNC to match the result
type. Without deep subsumption, unifyExpectedType would be sufficent.
See Note [Deep subsumption] in GHC.Tc.Utils.Unify.
* There are no changes to Quick Look at all.
* The type of `withDict` becomes ambiguous; so add -XAllowAmbiguousTypes to
GHC.Magic.Dict
* I fixed a small but egregious bug in GHC.Core.FVs.varTypeTyCoFVs, where
we'd forgotten to take the free vars of the multiplicity of an Id.
* I also had to fix tcSplitNestedSigmaTys
When I did the shallow-subsumption patch
commit 2b792facab46f7cdd09d12e79499f4e0dcd4293f
Date: Sun Feb 2 18:23:11 2020 +0000
Simple subsumption
I changed tcSplitNestedSigmaTys to not look through function arrows
any more. But that was actually an un-forced change. This function
is used only in
* Improving error messages in GHC.Tc.Gen.Head.addFunResCtxt
* Validity checking for default methods: GHC.Tc.TyCl.checkValidClass
* A couple of calls in the GHCi debugger: GHC.Runtime.Heap.Inspect
All to do with validity checking and error messages. Acutally its
fine to look under function arrows here, and quite useful a test
DeepSubsumption05 (a test motivated by a build failure in the
`lens` package) shows.
The fix is easy. I added Note [tcSplitNestedSigmaTys].
|
|
|
|
|
|
|
|
|
|
|
|
| |
There was some confusion about whether FUN/TYPE/One/Many should be
BuiltInSyntax or UserSyntax. The answer is certainly UserSyntax as
BuiltInSyntax is for things which are directly constructed by the parser
rather than going through normal renaming channels.
I fixed all the obviously wrong places I could find and added a test for
the original bug which was caused by this (#21752)
Fixes #21752 #20695 #18302
|
|
|
|
|
| |
Previously several tests' output were unnecessarily dependent on version
numbers, particularly of `base`. Fix this.
|
|
|
|
|
|
|
|
|
| |
To 0.9.0 and 4.17.0 respectively.
Bumps array, deepseq, directory, filepath, haskeline, hpc, parsec, stm,
terminfo, text, unix, haddock, and hsc2hs submodules.
(cherry picked from commit ba47b95122b7b336ce1cc00896a47b584ad24095)
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
The main fix for #21667 is the new call to tcInstTypeBnders
in tcHsPartialSigType. It was really a simple omission before.
I also moved the decision about whether we need to apply the
Monomorphism Restriction, from `decideGeneralisationPlan` to
`tcPolyInfer`. That removes a flag from the InferGen constructor,
which is good.
But more importantly, it allows the new function,
checkMonomorphismRestriction
called from `tcPolyInfer`, to "see" the `Types` involved rather than
the `HsTypes`. And that in turn matters because we invoke the MR for
partial signatures if none of the partial signatures in the group have
any overloading context; and we can't answer that question for HsTypes.
See Note [Partial type signatures and the monomorphism restriction]
in GHC.Tc.Gen.Bind.
This latter is really a pre-existing bug.
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This commit fixes #20312
It deprecates "TypeInType" extension
according to the following proposal:
https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0083-no-type-in-type.rst
It has been already implemented.
The migration strategy:
1. Disable TypeInType
2. Enable both DataKinds and PolyKinds extensions
Metric Decrease:
T16875
|
|
|
|
|
|
|
|
|
|
|
|
| |
This moves handling of the magic 'withDict' function from the desugarer
to the typechecker. Details in Note [withDict].
I've extracted a part of T16646Fail to a separate file T16646Fail2,
because the new error in 'reify' hides the errors from 'f' and 'g'.
WithDict now works with casts, this fixes #21328.
Part of #19915
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
The function breakTyVarCycle_maybe has been installed
in a dark corner of GHC to catch some gremlins (a.k.a.
occurs-check failures) who lurk
there. But it previously only caught gremlins of the
form (a ~ ... F a ...), where some of our intrepid users
have spawned gremlins of the form (G a ~ ... F (G a) ...).
This commit improves breakTyVarCycle_maybe (and renames
it to breakTyEqCycle_maybe) to catch the new gremlins.
Happily, the change is remarkably small.
The gory details are in Note [Type equality cycles].
Test cases: typecheck/should_compile/{T21515,T21473}.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This patch typechecks record updates by desugaring them inside
the typechecker using the HsExpansion mechanism, and then typechecking
this desugared result.
Example:
data T p q = T1 { x :: Int, y :: Bool, z :: Char }
| T2 { v :: Char }
| T3 { x :: Int }
| T4 { p :: Float, y :: Bool, x :: Int }
| T5
The record update `e { x=e1, y=e2 }` desugars as follows
e { x=e1, y=e2 }
===>
let { x' = e1; y' = e2 } in
case e of
T1 _ _ z -> T1 x' y' z
T4 p _ _ -> T4 p y' x'
The desugared expression is put into an HsExpansion, and we typecheck
that.
The full details are given in Note [Record Updates] in GHC.Tc.Gen.Expr.
Fixes #2595 #3632 #10808 #10856 #16501 #18311 #18802 #21158 #21289
Updates haddock submodule
|
|
|
|
| |
Fixes #21336.
|
|
|
|
|
|
| |
This is now fixed on master and 9.2 branch.
Closes #21558
|
|
|
|
|
| |
Those files were moved to the perf/ subtree in 11c9a469, and then
accidentally reintroduced in 680ef2c8.
|
|
|
|
| |
This missing guard gave rise to #21519.
|
|
|
|
|
|
|
| |
We assumed the wrapper for an unlifted binding is the identity,
but as #21516 showed, that is no always true.
Solution is simple: use it.
|