Language.PureScript.TypeChecker.Monad

Monads for type checking and type inference and associated data types

Documentation

data Substitution

A substitution of unification variables for types or kinds

Constructors

Substitution

Fields

• substType :: Map Int Type

  Type substitution

• substKind :: Map Int Kind

  Kind substitution

emptySubstitution :: Substitution

An empty substitution

data CheckState

State required for type checking

Constructors

CheckState

Fields

• checkEnv :: Environment

  The current Environment

• checkNextType :: Int

  The next type unification variable

• checkNextKind :: Int

  The next kind unification variable

• checkNextSkolem :: Int

  The next skolem variable

• checkNextSkolemScope :: Int

  The next skolem scope constant

• checkCurrentModule :: Maybe ModuleName

  The current module

• checkSubstitution :: Substitution

  The current substitution

• checkHints :: [ErrorMessageHint]

  The current error message hint stack. This goes into state, rather than using rethrow, since this way, we can provide good error messages during instance resolution.

emptyCheckState :: Environment -> CheckState

Create an empty CheckState

type Unknown = Int

Unification variables

bindNames :: MonadState CheckState m => Map (Qualified Ident) (Type, NameKind, NameVisibility) -> m a -> m a

Temporarily bind a collection of names to values

bindTypes :: MonadState CheckState m => Map (Qualified (ProperName TypeName)) (Kind, TypeKind) -> m a -> m a

Temporarily bind a collection of names to types

withScopedTypeVars :: (MonadState CheckState m, MonadWriter MultipleErrors m) => ModuleName -> [(Text, Kind)] -> m a -> m a

Temporarily bind a collection of names to types

withErrorMessageHint :: (MonadState CheckState m, MonadError MultipleErrors m) => ErrorMessageHint -> m a -> m a

getHints :: MonadState CheckState m => m [ErrorMessageHint]

These hints are added at the front, so the most nested hint occurs at the front, but the simplifier assumes the reverse order.

rethrowWithPositionTC :: (MonadState CheckState m, MonadError MultipleErrors m) => SourceSpan -> m a -> m a

warnAndRethrowWithPositionTC :: (MonadState CheckState m, MonadError MultipleErrors m, MonadWriter MultipleErrors m) => SourceSpan -> m a -> m a

withTypeClassDictionaries :: MonadState CheckState m => [NamedDict] -> m a -> m a

Temporarily make a collection of type class dictionaries available

getTypeClassDictionaries :: MonadState CheckState m => m (Map (Maybe ModuleName) (Map (Qualified (ProperName ClassName)) (Map (Qualified Ident) NamedDict)))

Get the currently available map of type class dictionaries

lookupTypeClassDictionaries :: MonadState CheckState m => Maybe ModuleName -> m (Map (Qualified (ProperName ClassName)) (Map (Qualified Ident) NamedDict))

Lookup type class dictionaries in a module.

bindLocalVariables :: MonadState CheckState m => [(Ident, Type, NameVisibility)] -> m a -> m a

Temporarily bind a collection of names to local variables

bindLocalTypeVariables :: MonadState CheckState m => ModuleName -> [(ProperName TypeName, Kind)] -> m a -> m a

Temporarily bind a collection of names to local type variables

makeBindingGroupVisible :: MonadState CheckState m => m ()

Update the visibility of all names to Defined

withBindingGroupVisible :: MonadState CheckState m => m a -> m a

Update the visibility of all names to Defined in the scope of the provided action

preservingNames :: MonadState CheckState m => m a -> m a

Perform an action while preserving the names from the Environment.

lookupVariable :: (e ~ MultipleErrors, MonadState CheckState m, MonadError e m) => Qualified Ident -> m Type

Lookup the type of a value by name in the Environment

getVisibility :: (e ~ MultipleErrors, MonadState CheckState m, MonadError e m) => Qualified Ident -> m NameVisibility

Lookup the visibility of a value by name in the Environment

checkVisibility :: (e ~ MultipleErrors, MonadState CheckState m, MonadError e m) => Qualified Ident -> m ()

Assert that a name is visible

lookupTypeVariable :: (e ~ MultipleErrors, MonadState CheckState m, MonadError e m) => ModuleName -> Qualified (ProperName TypeName) -> m Kind

Lookup the kind of a type by name in the Environment

getEnv :: MonadState CheckState m => m Environment

Get the current Environment

getLocalContext :: MonadState CheckState m => m Context

Get locally-bound names in context, to create an error message.

putEnv :: MonadState CheckState m => Environment -> m ()

Update the Environment

modifyEnv :: MonadState CheckState m => (Environment -> Environment) -> m ()

Modify the Environment

runCheck :: Functor m => StateT CheckState m a -> m (a, Environment)

Run a computation in the typechecking monad, starting with an empty Environment

runCheck' :: Functor m => CheckState -> StateT CheckState m a -> m (a, Environment)

Run a computation in the typechecking monad, failing with an error, or succeeding with a return value and the final Environment.

guardWith :: MonadError e m => e -> Bool -> m ()

Make an assertion, failing with an error message

captureSubstitution :: MonadState CheckState m => m a -> m (a, Substitution)

Run a computation in the substitution monad, generating a return value and the final substitution.

capturingSubstitution :: MonadState CheckState m => (a -> Substitution -> b) -> m a -> m b

withFreshSubstitution :: MonadState CheckState m => m a -> m a

withoutWarnings :: MonadWriter w m => m a -> m (a, w)