Language.PureScript.TypeChecker.Roles

Role inference

Documentation

lookupRoles :: Environment -> Qualified (ProperName 'TypeName) -> [Role]

Lookup the roles for a type in the environment. If the type does not have roles (e.g. is a type synonym or a type variable), then this function returns an empty list.

checkRoles

Arguments

:: forall m. MonadError MultipleErrors m

=> [(Text, Maybe SourceType, Role)]

type parameters for the data type whose roles we are checking

-> [Role]

roles declared for the data type

-> m ()

Compares the inferred roles to the explicitly declared roles and ensures that the explicitly declared roles are not more permissive than the inferred ones.

checkRoleDeclarationArity :: forall m. MonadError MultipleErrors m => ProperName 'TypeName -> [Role] -> Int -> m ()

inferRoles

Arguments

:: Environment

-> ModuleName

-> ProperName 'TypeName

The name of the data type whose roles we are checking

-> [(Text, Maybe SourceType)]

type parameters for the data type whose roles we are checking

-> [DataConstructorDeclaration]

constructors of the data type whose roles we are checking

-> [Role]

Infers roles for the given data type declaration.

inferDataBindingGroupRoles :: Environment -> ModuleName -> [RoleDeclarationData] -> [DataDeclaration] -> ProperName 'TypeName -> [(Text, Maybe SourceType)] -> [Role]