Base.TopEnv

The module TopEnv implements environments for qualified and possibly ambiguous identifiers. An identifier is ambiguous if two different entities are imported under the same name or if a local definition uses the same name as an imported entity. Following an idea presented in a paper by Diatchki, Jones and Hallgren (2002), an identifier is associated with a list of entities in order to handle ambiguous names properly.

In general, two entities are considered equal if the names of their original definitions match. However, in the case of algebraic data types it is possible to hide some or all of their data constructors on import and export, respectively. In this case we have to merge both imports such that all data constructors which are visible through any import path are visible in the current module. The class Entity is used to handle this merge.

The code in this module ensures that the list of entities returned by the functions lookupTopEnv and qualLookupTopEnv contains exactly one element for each imported entity regardless of how many times and from which module(s) it was imported. Thus, the result of these function is a list with exactly one element if and only if the identifier is unambiguous. The module names associated with an imported entity identify the modules from which the entity was imported.

Data types

newtype TopEnv a

Top level environment

Constructors

TopEnv

Fields

• topEnvMap :: Map QualIdent [(Source, a)]

Instances

Functor TopEnv

Defined in Base.TopEnv

Methods

fmap :: (a -> b) -> TopEnv a -> TopEnv b

(<$) :: a -> TopEnv b -> TopEnv a

Show a => Show (TopEnv a)

Defined in Base.TopEnv

Methods

showsPrec :: Int -> TopEnv a -> ShowS

show :: TopEnv a -> String

showList :: [TopEnv a] -> ShowS

SubstKind a => SubstKind (TopEnv a)

Defined in Base.KindSubst

Methods

subst :: KindSubst -> TopEnv a -> TopEnv a

SubstType a => SubstType (TopEnv a)

Defined in Base.TypeSubst

Methods

subst :: TypeSubst -> TopEnv a -> TopEnv a

class Entity a where

Minimal complete definition

origName

Methods

origName :: a -> QualIdent

merge :: a -> a -> Maybe a

Instances

Entity PrecInfo

Defined in Env.OpPrec

Methods

origName :: PrecInfo -> QualIdent

merge :: PrecInfo -> PrecInfo -> Maybe PrecInfo

Entity TypeInfo

Defined in Env.TypeConstructor

Methods

origName :: TypeInfo -> QualIdent

merge :: TypeInfo -> TypeInfo -> Maybe TypeInfo

Entity TypeKind

Defined in Env.Type

Methods

origName :: TypeKind -> QualIdent

merge :: TypeKind -> TypeKind -> Maybe TypeKind

Entity ValueInfo

Defined in Env.Value

Methods

origName :: ValueInfo -> QualIdent

merge :: ValueInfo -> ValueInfo -> Maybe ValueInfo

creation and insertion

emptyTopEnv :: TopEnv a

Empty TopEnv

predefTopEnv :: QualIdent -> a -> TopEnv a -> TopEnv a

Insert an Entity into a TopEnv as a predefined Entity

importTopEnv :: Entity a => ModuleIdent -> Ident -> a -> TopEnv a -> TopEnv a

Insert an Entity as unqualified into a TopEnv

qualImportTopEnv :: Entity a => ModuleIdent -> Ident -> a -> TopEnv a -> TopEnv a

Insert an Entity as qualified into a TopEnv

bindTopEnv :: Ident -> a -> TopEnv a -> TopEnv a

qualBindTopEnv :: QualIdent -> a -> TopEnv a -> TopEnv a

rebindTopEnv :: Ident -> a -> TopEnv a -> TopEnv a

qualRebindTopEnv :: QualIdent -> a -> TopEnv a -> TopEnv a

unbindTopEnv :: Ident -> TopEnv a -> TopEnv a

qualUnbindTopEnv :: QualIdent -> TopEnv a -> TopEnv a

lookupTopEnv :: Ident -> TopEnv a -> [a]

qualLookupTopEnv :: QualIdent -> TopEnv a -> [a]

qualElemTopEnv :: QualIdent -> TopEnv a -> Bool

allImports :: TopEnv a -> [(QualIdent, a)]

moduleImports :: ModuleIdent -> TopEnv a -> [(Ident, a)]

localBindings :: TopEnv a -> [(Ident, a)]

allLocalBindings :: TopEnv a -> [(QualIdent, a)]

allBindings :: TopEnv a -> [(QualIdent, a)]

allEntities :: TopEnv a -> [a]