ghc-8.2.0.20170404: The GHC API

Safe HaskellNone
LanguageHaskell2010

TcRnTypes (signature[?])

Synopsis

Documentation

type TcRnIf a b = IOEnv (Env a b) Source #

type TcM = TcRn Source #

Historical "type-checking monad" (now it's just TcRn).

type RnM = TcRn Source #

Historical "renaming monad" (now it's just TcRn).

type IfM lcl = TcRnIf IfGblEnv lcl Source #

type IfG = IfM () Source #

type TcRef a = IORef a Source #

Type alias for IORef; the convention is we'll use this for mutable bits of data in TcGblEnv which are updated during typechecking and returned at the end.

data Env gbl lcl Source #

Constructors

Env 

Fields

Instances

ContainsModule gbl => ContainsModule (Env gbl lcl) # 

Methods

extractModule :: Env gbl lcl -> Module Source #

ContainsDynFlags (Env gbl lcl) # 

Methods

extractDynFlags :: Env gbl lcl -> DynFlags Source #

data TcGblEnv Source #

TcGblEnv describes the top-level of the module at the point at which the typechecker is finished work. It is this structure that is handed on to the desugarer For state that needs to be updated during the typechecking phase and returned at end, use a TcRef (= IORef).

Constructors

TcGblEnv 

Fields

data IfGblEnv Source #

Constructors

IfGblEnv 

data FrontendResult Source #

FrontendResult describes the result of running the frontend of a Haskell module. Usually, you'll get a FrontendTypecheck, since running the frontend involves typechecking a program, but for an hs-boot merge you'll just get a ModIface, since no actual typechecking occurred.

This data type really should be in HscTypes, but it needs to have a TcGblEnv which is only defined here.

data ImportAvails Source #

ImportAvails summarises what was imported from where, irrespective of whether the imported things are actually used or not. It is used:

  • when processing the export list,
  • when constructing usage info for the interface file,
  • to identify the list of directly imported modules for initialisation purposes and for optimised overlap checking of family instances,
  • when figuring out what things are really unused

Constructors

ImportAvails 

Fields

  • imp_mods :: ImportedMods

    Domain is all directly-imported modules

    See the documentation on ImportedModsVal in HscTypes for the meaning of the fields.

    We need a full ModuleEnv rather than a ModuleNameEnv here, because we might be importing modules of the same name from different packages. (currently not the case, but might be in the future).

  • imp_dep_mods :: DModuleNameEnv (ModuleName, IsBootInterface)

    Home-package modules needed by the module being compiled

    It doesn't matter whether any of these dependencies are actually used when compiling the module; they are listed if they are below it at all. For example, suppose M imports A which imports X. Then compiling M might not need to consult X.hi, but X is still listed in M's dependencies.

  • imp_dep_pkgs :: Set InstalledUnitId

    Packages needed by the module being compiled, whether directly, or via other modules in this package, or via modules imported from other packages.

  • imp_trust_pkgs :: Set InstalledUnitId

    This is strictly a subset of imp_dep_pkgs and records the packages the current module needs to trust for Safe Haskell compilation to succeed. A package is required to be trusted if we are dependent on a trustworthy module in that package. While perhaps making imp_dep_pkgs a tuple of (UnitId, Bool) where True for the bool indicates the package is required to be trusted is the more logical design, doing so complicates a lot of code not concerned with Safe Haskell. See Note [RnNames . Tracking Trust Transitively]

  • imp_trust_own_pkg :: Bool

    Do we require that our own package is trusted? This is to handle efficiently the case where a Safe module imports a Trustworthy module that resides in the same package as it. See Note [RnNames . Trust Own Package]

  • imp_orphs :: [Module]

    Orphan modules below us in the import tree (and maybe including us for imported modules)

  • imp_finsts :: [Module]

    Family instance modules below us in the import tree (and maybe including us for imported modules)

plusImportAvails :: ImportAvails -> ImportAvails -> ImportAvails Source #

Union two ImportAvails

This function is a key part of Import handling, basically for each import we create a separate ImportAvails structure and then union them all together with this function.

data TcTyThing Source #

A typecheckable thing available in a local context. Could be AGlobal TyThing, but also lexically scoped variables, etc. See TcEnv for how to retrieve a TyThing given a Name.

data IdBindingInfo Source #

Describes how an Id is bound.

It is used for the following purposes:

a) for static forms in TcExpr.checkClosedInStaticForm and b) to figure out when a nested binding can be generalised (in TcBinds.decideGeneralisationPlan).

See Note [Meaning of IdBindingInfo].

data IsGroupClosed Source #

Tells if a group of binders is closed.

When it is not closed, it provides a map of binder ids to the free vars in their right-hand sides.

data CompleteMatch Source #

A list of conlikes which represents a complete pattern match. These arise from COMPLETE signatures.

Constructors

CompleteMatch 

Fields

data PArrBuiltin Source #

Constructors

PArrBuiltin 

Fields

data DsMetaVal Source #

Constructors

DsBound Id 
DsSplice (HsExpr Id) 

data SpliceType Source #

Constructors

Typed 
Untyped 

data ForeignSrcLang :: * Source #

Constructors

LangC 
LangCxx 
LangObjc 
LangObjcxx 

Instances

Eq ForeignSrcLang 
Show ForeignSrcLang 
Generic ForeignSrcLang 
type Rep ForeignSrcLang 
type Rep ForeignSrcLang = D1 * (MetaData "ForeignSrcLang" "GHC.ForeignSrcLang.Type" "ghc-boot-th-8.2.0.20170404" False) ((:+:) * ((:+:) * (C1 * (MetaCons "LangC" PrefixI False) (U1 *)) (C1 * (MetaCons "LangCxx" PrefixI False) (U1 *))) ((:+:) * (C1 * (MetaCons "LangObjc" PrefixI False) (U1 *)) (C1 * (MetaCons "LangObjcxx" PrefixI False) (U1 *))))

type Xi = Type Source #

type Cts = Bag Ct Source #

superClassesMightHelp :: Ct -> Bool Source #

True if taking superclasses of givens, or of wanteds (to perhaps expose more equalities or functional dependencies) might help to solve this constraint. See Note [When superclasses help]

getUserTypeErrorMsg :: Ct -> Maybe Type Source #

A constraint is considered to be a custom type error, if it contains custom type errors anywhere in it. See Note [Custom type errors in constraints]

ctFlavour :: Ct -> CtFlavour Source #

Get the flavour of the given Ct

ctEqRel :: Ct -> EqRel Source #

Get the equality relation for the given Ct

mkTcEqPredLikeEv :: CtEvidence -> TcType -> TcType -> TcType Source #

Makes a new equality predicate with the same role as the given evidence.

mkGivens :: CtLoc -> [EvId] -> [Ct] Source #

ctEvEqRel :: CtEvidence -> EqRel Source #

Get the equality relation relevant for a CtEvidence

tyCoVarsOfCt :: Ct -> TcTyCoVarSet Source #

Returns free variables of constraints as a non-deterministic set

tyCoVarsOfCts :: Cts -> TcTyCoVarSet Source #

Returns free variables of a bag of constraints as a non-deterministic set. See Note [Deterministic FV] in FV.

tyCoVarsOfCtList :: Ct -> [TcTyCoVar] Source #

Returns free variables of constraints as a deterministically ordered. list. See Note [Deterministic FV] in FV.

tyCoVarsOfCtsList :: Cts -> [TcTyCoVar] Source #

Returns free variables of a bag of constraints as a deterministically odered list. See Note [Deterministic FV] in FV.

tyCoVarsOfWC :: WantedConstraints -> TyCoVarSet Source #

Returns free variables of WantedConstraints as a non-deterministic set. See Note [Deterministic FV] in FV.

tyCoVarsOfWCList :: WantedConstraints -> [TyCoVar] Source #

Returns free variables of WantedConstraints as a deterministically ordered list. See Note [Deterministic FV] in FV.

lexprCtOrigin :: LHsExpr Name -> CtOrigin Source #

Extract a suitable CtOrigin from a HsExpr

matchesCtOrigin :: MatchGroup Name (LHsExpr Name) -> CtOrigin Source #

Extract a suitable CtOrigin from a MatchGroup

grhssCtOrigin :: GRHSs Name (LHsExpr Name) -> CtOrigin Source #

Extract a suitable CtOrigin from guarded RHSs

data ErrorThing Source #

A thing that can be stored for error message generation only. It is stored with a function to zonk and tidy the thing.

Constructors

Outputable a => ErrorThing a (Maybe Arity) (TidyEnv -> a -> TcM (TidyEnv, a)) 

mkErrorThing :: Outputable a => a -> ErrorThing Source #

Make an ErrorThing that doesn't need tidying or zonking

errorThingNumArgs_maybe :: ErrorThing -> Maybe Arity Source #

Retrieve the # of arguments in the error thing, if known

data TypeOrKind Source #

Flag to see whether we're type-checking terms or kind-checking types

Constructors

TypeLevel 
KindLevel 

data TcEvDest Source #

A place for type-checking evidence to go after it is generated. Wanted equalities are always HoleDest; other wanteds are always EvVarDest.

Constructors

EvVarDest EvVar

bind this var to the evidence

HoleDest CoercionHole

fill in this hole with the evidence See Note [Coercion holes] in TyCoRep

toKindLoc :: CtLoc -> CtLoc Source #

Take a CtLoc and moves it to the kind level

ctEvRole :: CtEvidence -> Role Source #

Get the role relevant for a CtEvidence

data TcPlugin Source #

Constructors

TcPlugin 

Fields

data TcPluginResult Source #

Constructors

TcPluginContradiction [Ct]

The plugin found a contradiction. The returned constraints are removed from the inert set, and recorded as insoluble.

TcPluginOk [(EvTerm, Ct)] [Ct]

The first field is for constraints that were solved. These are removed from the inert set, and the evidence for them is recorded. The second field contains new work, that should be processed by the constraint solver.

unsafeTcPluginTcM :: TcM a -> TcPluginM a Source #

This function provides an escape for direct access to the TcM monad. It should not be used lightly, and the provided TcPluginM API should be favoured instead.

getEvBindsTcPluginM :: TcPluginM EvBindsVar Source #

Access the EvBindsVar carried by the TcPluginM during constraint solving. Returns Nothing if invoked during tcPluginInit or tcPluginStop.

data ShadowInfo Source #

Constructors

WDeriv 
WOnly 

type CtFlavourRole = (CtFlavour, EqRel) Source #

Whether or not one Ct can rewrite another is determined by its flavour and its equality relation. See also Note [Flavours with roles] in TcSMonad

ctEvFlavourRole :: CtEvidence -> CtFlavourRole Source #

Extract the flavour, role, and boxity from a CtEvidence

ctFlavourRole :: Ct -> CtFlavourRole Source #

Extract the flavour, role, and boxity from a Ct

type TcId = Id Source #

data Hole Source #

An expression or type hole

Constructors

ExprHole UnboundVar

Either an out-of-scope variable or a "true" hole in an expression (TypedHoles)

TypeHole OccName

A hole in a type (PartialTypeSignatures)

data NameShape Source #

A NameShape is a substitution on Names that can be used to refine the identities of a hole while we are renaming interfaces (see RnModIface). Specifically, a NameShape for ns_module_name A, defines a mapping from {A.T} (for some OccName T) to some arbitrary other Name.

The most intruiging thing about a NameShape, however, is how it's constructed. A NameShape is *implied* by the exported AvailInfos of the implementor of an interface: if an implementor of signature H exports M.T, you implicitly define a substitution from {H.T} to M.T. So a NameShape is computed from the list of AvailInfos that are exported by the implementation of a module, or successively merged together by the export lists of signatures which are joining together.

It's not the most obvious way to go about doing this, but it does seem to work!

NB: Can't boot this and put it in NameShape because then we start pulling in too many DynFlags things.