Moduleghc-9.10.3GHC2021

GHC.Tc.Plugin

This module provides an interface for typechecker plugins to access select functions of the TcM, principally those to do with reading parts of the state.

2 types
27 values

Packageghc-9.10.3
Exports29
LanguageGHC2021
LicenceBSD-3-Clause
SourcePlugin.hs

Basic TcPluginM functionality

4 declarations

newtypenewtype TcPluginM a

TcPluginM is the monad in which type-checking plugins operate.

Instances4Monad, Functor, MonadFail, Applicative

Monad TcPluginMDefined in ghc-9.10.3 · GHC.Tc.Types
Functor TcPluginMDefined in ghc-9.10.3 · GHC.Tc.Types
MonadFail TcPluginMDefined in ghc-9.10.3 · GHC.Tc.Types
Applicative TcPluginMDefined in ghc-9.10.3 · GHC.Tc.Types

valuetcPluginIO :: IO a -> TcPluginM a

Perform some IO, typically to interact with an external tool.

valuetcPluginTrace :: String -> SDoc -> TcPluginM ()

Output useful for debugging the compiler.

valueunsafeTcPluginTcM :: TcM a -> TcPluginM a

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.

Finding Modules and Names

3 declarations

datadata FindResult

The result of searching for an imported module.

NB: FindResult manages both user source-import lookups (which can result in Module) as well as direct imports for interfaces (which always result in InstalledModule).

Constructors

Found ModLocation Module
The module was found
NoPackage Unit
The requested unit was not found
FoundMultiple [(Module, ModuleOrigin)]
_Error_: both in multiple packages
NotFound
Not found
- fr_paths :: [FilePath]
  Places where I looked
- fr_pkg :: Maybe Unit
  Just p => module is in this unit's manifest, but couldn't find the .hi file
- fr_mods_hidden :: [Unit]
  Module is in these units, but the *module* is hidden
- fr_pkgs_hidden :: [Unit]
  Module is in these units, but the *unit* is hidden
- fr_unusables :: [UnusableUnit]
  Module is in these units, but it is unusable
- fr_suggestions :: [ModuleSuggestion]
  Possible mis-spelled modules

valuefindImportedModule :: ModuleName -> PkgQual -> TcPluginM FindResult

valuelookupOrig :: Module -> OccName -> TcPluginM Name

Looking up Names in the typechecking environment

6 declarations

valuetcLookupGlobal :: Name -> TcPluginM TyThing

valuetcLookupTyCon :: Name -> TcPluginM TyCon

valuetcLookupDataCon :: Name -> TcPluginM DataCon

valuetcLookupClass :: Name -> TcPluginM Class

valuetcLookup :: Name -> TcPluginM TcTyThing

valuetcLookupId :: Name -> TcPluginM Id

Getting the TcM state

6 declarations

valuegetTopEnv :: TcPluginM HscEnv

valuegetTargetPlatform :: TcPluginM Platform

valuegetEnvs :: TcPluginM (TcGblEnv, TcLclEnv)

valuegetInstEnvs :: TcPluginM InstEnvs

valuegetFamInstEnvs :: TcPluginM (FamInstEnv, FamInstEnv)

valuematchFam :: TyCon -> [Type] -> TcPluginM (Maybe Reduction)

Type variables

3 declarations

valuenewUnique :: TcPluginM Unique

valuenewFlexiTyVar :: Kind -> TcPluginM TcTyVar

valueisTouchableTcPluginM :: TcTyVar -> TcPluginM Bool

Zonking

2 declarations

valuezonkTcType :: TcType -> TcPluginM TcType

Confused by zonking? See Note [What is zonking?] in GHC.Tc.Zonk.Type.

valuezonkCt :: Ct -> TcPluginM Ct

Creating constraints

3 declarations

valuenewWanted :: CtLoc -> PredType -> TcPluginM CtEvidence

Create a new Wanted constraint with the given CtLoc.

valuenewGiven

Create a new given constraint, with the supplied evidence.

This should only be invoked within tcPluginSolve.

valuenewCoercionHole :: PredType -> TcPluginM CoercionHole

Create a fresh coercion hole. This should only be invoked within tcPluginSolve.

Manipulating evidence bindings

2 declarations

valuenewEvVar :: PredType -> TcPluginM EvVar

Create a fresh evidence variable.

This should only be invoked within tcPluginSolve.

valuesetEvBind :: EvBindsVar -> EvBind -> TcPluginM ()

Bind an evidence variable.

This should only be invoked within tcPluginSolve.