ghc-8.8.1: The GHC API
Safe HaskellNone
LanguageHaskell2010

RdrName

Description

GHC uses several kinds of name internally:

  • OccName: see OccName
  • RdrName is the type of names that come directly from the parser. They have not yet had their scoping and binding resolved by the renamer and can be thought of to a first approximation as an OccName with an optional module qualifier
  • Name: see Name
  • Id: see Id
  • Var: see Var
Synopsis

The main type

data RdrName Source #

Reader Name

Do not use the data constructors of RdrName directly: prefer the family of functions that creates them, such as mkRdrUnqual

  • Note: A Located RdrName will only have API Annotations if it is a compound one, e.g.
`bar`
( ~ )

Constructors

Unqual OccName

Unqualified name

Used for ordinary, unqualified occurrences, e.g. x, y or Foo. Create such a RdrName with mkRdrUnqual

Qual ModuleName OccName

Qualified name

A qualified name written by the user in source code. The module isn't necessarily the module where the thing is defined; just the one from which it is imported. Examples are Bar.x, Bar.y or Bar.Foo. Create such a RdrName with mkRdrQual

Orig Module OccName

Original name

An original name; the module is the defining module. This is used when GHC generates code that will be fed into the renamer (e.g. from deriving clauses), but where we want to say "Use Prelude.map dammit". One of these can be created with mkOrig

Exact Name

Exact name

We know exactly the Name. This is used:

  1. When the parser parses built-in syntax like [] and (,), but wants a RdrName from it
  2. By Template Haskell, when TH has generated a unique name

Such a RdrName can be created by using getRdrName on a Name

Instances

Instances details
Eq RdrName Source # 
Instance details

Defined in RdrName

Methods

(==) :: RdrName -> RdrName -> Bool #

(/=) :: RdrName -> RdrName -> Bool #

Data RdrName Source # 
Instance details

Defined in RdrName

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> RdrName -> c RdrName #

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c RdrName #

toConstr :: RdrName -> Constr #

dataTypeOf :: RdrName -> DataType #

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c RdrName) #

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c RdrName) #

gmapT :: (forall b. Data b => b -> b) -> RdrName -> RdrName #

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> RdrName -> r #

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> RdrName -> r #

gmapQ :: (forall d. Data d => d -> u) -> RdrName -> [u] #

gmapQi :: Int -> (forall d. Data d => d -> u) -> RdrName -> u #

gmapM :: Monad m => (forall d. Data d => d -> m d) -> RdrName -> m RdrName #

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> RdrName -> m RdrName #

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> RdrName -> m RdrName #

Ord RdrName Source # 
Instance details

Defined in RdrName

OutputableBndr RdrName Source # 
Instance details

Defined in RdrName

Outputable RdrName Source # 
Instance details

Defined in RdrName

HasOccName RdrName Source # 
Instance details

Defined in RdrName

Construction

mkQual :: NameSpace -> (FastString, FastString) -> RdrName Source #

Make a qualified RdrName in the given namespace and where the ModuleName and the OccName are taken from the first and second elements of the tuple respectively

getRdrName :: NamedThing thing => thing -> RdrName Source #

Destruction

Local mapping of RdrName to Name

data LocalRdrEnv Source #

Local Reader Environment

This environment is used to store local bindings (let, where, lambda, case). It is keyed by OccName, because we never use it for qualified names We keep the current mapping, *and* the set of all Names in scope Reason: see Note [Splicing Exact names] in RnEnv

Instances

Instances details
Outputable LocalRdrEnv Source # 
Instance details

Defined in RdrName

Global mapping of RdrName to GlobalRdrElts

type GlobalRdrEnv = OccEnv [GlobalRdrElt] Source #

Global Reader Environment

Keyed by OccName; when looking up a qualified name we look up the OccName part, and then check the Provenance to see if the appropriate qualification is valid. This saves routinely doubling the size of the env by adding both qualified and unqualified names to the domain.

The list in the codomain is required because there may be name clashes These only get reported on lookup, not on construction

INVARIANT 1: All the members of the list have distinct gre_name fields; that is, no duplicate Names

INVARIANT 2: Imported provenance => Name is an ExternalName However LocalDefs can have an InternalName. This happens only when type-checking a [d| ... |] Template Haskell quotation; see this note in RnNames Note [Top-level Names in Template Haskell decl quotes]

INVARIANT 3: If the GlobalRdrEnv maps [occ -> gre], then greOccName gre = occ

NB: greOccName gre is usually the same as nameOccName (gre_name gre), but not always in the case of record seectors; see greOccName

lookupGRE_Name :: GlobalRdrEnv -> Name -> Maybe GlobalRdrElt Source #

Look for precisely this Name in the environment. This tests whether it is in scope, ignoring anything else that might be in scope with the same OccName.

lookupGRE_FieldLabel :: GlobalRdrEnv -> FieldLabel -> Maybe GlobalRdrElt Source #

Look for a particular record field selector in the environment, where the selector name and field label may be different: the GlobalRdrEnv is keyed on the label. See Note [Parents for record fields] for why this happens.

lookupGRE_Name_OccName :: GlobalRdrEnv -> Name -> OccName -> Maybe GlobalRdrElt Source #

Look for precisely this Name in the environment, but with an OccName that might differ from that of the Name. See lookupGRE_FieldLabel and Note [Parents for record fields].

transformGREs :: (GlobalRdrElt -> GlobalRdrElt) -> [OccName] -> GlobalRdrEnv -> GlobalRdrEnv Source #

Apply a transformation function to the GREs for these OccNames

pickGREs :: RdrName -> [GlobalRdrElt] -> [GlobalRdrElt] Source #

Takes a list of GREs which have the right OccName x Pick those GREs that are in scope * Qualified, as x if want_qual is Qual M _ * Unqualified, as x if want_unqual is Unqual _

Return each such GRE, with its ImportSpecs filtered, to reflect how it is in scope qualified or unqualified respectively. See Note [GRE filtering]

pickGREsModExp :: ModuleName -> [GlobalRdrElt] -> [(GlobalRdrElt, GlobalRdrElt)] Source #

Pick GREs that are in scope *both* qualified *and* unqualified Return each GRE that is, as a pair (qual_gre, unqual_gre) These two GREs are the original GRE with imports filtered to express how it is in scope qualified an unqualified respectively

Used only for the 'module M' item in export list; see RnNames.exports_from_avail

GlobalRdrElts

gresFromAvails :: Maybe ImportSpec -> [AvailInfo] -> [GlobalRdrElt] Source #

make a GlobalRdrEnv where all the elements point to the same Provenance (useful for "hiding" imports, or imports with no details).

gresToAvailInfo :: [GlobalRdrElt] -> [AvailInfo] Source #

Takes a list of distinct GREs and folds them into AvailInfos. This is more efficient than mapping each individual GRE to an AvailInfo and the folding using plusAvail but needs the uniqueness assumption.

Global RdrName mapping elements: GlobalRdrElt, Provenance, ImportSpec

data GlobalRdrElt Source #

Global Reader Element

An element of the GlobalRdrEnv

Constructors

GRE 

Fields

Instances

Instances details
Eq GlobalRdrElt Source # 
Instance details

Defined in RdrName

Data GlobalRdrElt Source # 
Instance details

Defined in RdrName

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> GlobalRdrElt -> c GlobalRdrElt #

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c GlobalRdrElt #

toConstr :: GlobalRdrElt -> Constr #

dataTypeOf :: GlobalRdrElt -> DataType #

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c GlobalRdrElt) #

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c GlobalRdrElt) #

gmapT :: (forall b. Data b => b -> b) -> GlobalRdrElt -> GlobalRdrElt #

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> GlobalRdrElt -> r #

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> GlobalRdrElt -> r #

gmapQ :: (forall d. Data d => d -> u) -> GlobalRdrElt -> [u] #

gmapQi :: Int -> (forall d. Data d => d -> u) -> GlobalRdrElt -> u #

gmapM :: Monad m => (forall d. Data d => d -> m d) -> GlobalRdrElt -> m GlobalRdrElt #

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> GlobalRdrElt -> m GlobalRdrElt #

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> GlobalRdrElt -> m GlobalRdrElt #

Outputable GlobalRdrElt Source # 
Instance details

Defined in RdrName

unQualOK :: GlobalRdrElt -> Bool Source #

Test if an unqualified version of this thing would be in scope

qualSpecOK :: ModuleName -> ImportSpec -> Bool Source #

Is in scope qualified with the given module?

unQualSpecOK :: ImportSpec -> Bool Source #

Is in scope unqualified?

pprNameProvenance :: GlobalRdrElt -> SDoc Source #

Print out one place where the name was define/imported (With -dppr-debug, print them all)

data Parent Source #

The children of a Name are the things that are abbreviated by the ".." notation in export lists. See Note [Parents]

Constructors

NoParent 
ParentIs 

Fields

FldParent

See Note [Parents for record fields]

Instances

Instances details
Eq Parent Source # 
Instance details

Defined in RdrName

Methods

(==) :: Parent -> Parent -> Bool #

(/=) :: Parent -> Parent -> Bool #

Data Parent Source # 
Instance details

Defined in RdrName

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Parent -> c Parent #

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Parent #

toConstr :: Parent -> Constr #

dataTypeOf :: Parent -> DataType #

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Parent) #

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Parent) #

gmapT :: (forall b. Data b => b -> b) -> Parent -> Parent #

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Parent -> r #

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Parent -> r #

gmapQ :: (forall d. Data d => d -> u) -> Parent -> [u] #

gmapQi :: Int -> (forall d. Data d => d -> u) -> Parent -> u #

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Parent -> m Parent #

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Parent -> m Parent #

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Parent -> m Parent #

Outputable Parent Source # 
Instance details

Defined in RdrName

data ImportSpec Source #

Import Specification

The ImportSpec of something says how it came to be imported It's quite elaborate so that we can give accurate unused-name warnings.

Constructors

ImpSpec 

Instances

Instances details
Eq ImportSpec Source # 
Instance details

Defined in RdrName

Data ImportSpec Source # 
Instance details

Defined in RdrName

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> ImportSpec -> c ImportSpec #

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c ImportSpec #

toConstr :: ImportSpec -> Constr #

dataTypeOf :: ImportSpec -> DataType #

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c ImportSpec) #

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c ImportSpec) #

gmapT :: (forall b. Data b => b -> b) -> ImportSpec -> ImportSpec #

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> ImportSpec -> r #

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> ImportSpec -> r #

gmapQ :: (forall d. Data d => d -> u) -> ImportSpec -> [u] #

gmapQi :: Int -> (forall d. Data d => d -> u) -> ImportSpec -> u #

gmapM :: Monad m => (forall d. Data d => d -> m d) -> ImportSpec -> m ImportSpec #

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> ImportSpec -> m ImportSpec #

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> ImportSpec -> m ImportSpec #

Ord ImportSpec Source # 
Instance details

Defined in RdrName

Outputable ImportSpec Source # 
Instance details

Defined in RdrName

data ImpDeclSpec Source #

Import Declaration Specification

Describes a particular import declaration and is shared among all the Provenances for that decl

Constructors

ImpDeclSpec 

Fields

  • is_mod :: ModuleName

    Module imported, e.g. import Muggle Note the Muggle may well not be the defining module for this thing!

  • is_as :: ModuleName

    Import alias, e.g. from as M (or Muggle if there is no as clause)

  • is_qual :: Bool

    Was this import qualified?

  • is_dloc :: SrcSpan

    The location of the entire import declaration

Instances

Instances details
Eq ImpDeclSpec Source # 
Instance details

Defined in RdrName

Data ImpDeclSpec Source # 
Instance details

Defined in RdrName

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> ImpDeclSpec -> c ImpDeclSpec #

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c ImpDeclSpec #

toConstr :: ImpDeclSpec -> Constr #

dataTypeOf :: ImpDeclSpec -> DataType #

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c ImpDeclSpec) #

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c ImpDeclSpec) #

gmapT :: (forall b. Data b => b -> b) -> ImpDeclSpec -> ImpDeclSpec #

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> ImpDeclSpec -> r #

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> ImpDeclSpec -> r #

gmapQ :: (forall d. Data d => d -> u) -> ImpDeclSpec -> [u] #

gmapQi :: Int -> (forall d. Data d => d -> u) -> ImpDeclSpec -> u #

gmapM :: Monad m => (forall d. Data d => d -> m d) -> ImpDeclSpec -> m ImpDeclSpec #

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> ImpDeclSpec -> m ImpDeclSpec #

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> ImpDeclSpec -> m ImpDeclSpec #

Ord ImpDeclSpec Source # 
Instance details

Defined in RdrName

data ImpItemSpec Source #

Import Item Specification

Describes import info a particular Name

Constructors

ImpAll

The import had no import list, or had a hiding list

ImpSome

The import had an import list. The is_explicit field is True iff the thing was named explicitly in the import specs rather than being imported as part of a "..." group. Consider:

import C( T(..) )

Here the constructors of T are not named explicitly; only T is named explicitly.

Instances

Instances details
Eq ImpItemSpec Source # 
Instance details

Defined in RdrName

Data ImpItemSpec Source # 
Instance details

Defined in RdrName

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> ImpItemSpec -> c ImpItemSpec #

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c ImpItemSpec #

toConstr :: ImpItemSpec -> Constr #

dataTypeOf :: ImpItemSpec -> DataType #

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c ImpItemSpec) #

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c ImpItemSpec) #

gmapT :: (forall b. Data b => b -> b) -> ImpItemSpec -> ImpItemSpec #

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> ImpItemSpec -> r #

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> ImpItemSpec -> r #

gmapQ :: (forall d. Data d => d -> u) -> ImpItemSpec -> [u] #

gmapQi :: Int -> (forall d. Data d => d -> u) -> ImpItemSpec -> u #

gmapM :: Monad m => (forall d. Data d => d -> m d) -> ImpItemSpec -> m ImpItemSpec #

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> ImpItemSpec -> m ImpItemSpec #

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> ImpItemSpec -> m ImpItemSpec #

Ord ImpItemSpec Source # 
Instance details

Defined in RdrName

Utils for StarIsType

starInfo :: Bool -> RdrName -> SDoc Source #

Display info about the treatment of * under NoStarIsType.

With StarIsType, three properties of * hold:

(a) it is not an infix operator (b) it is always in scope (c) it is a synonym for Data.Kind.Type

However, the user might not know that he's working on a module with NoStarIsType and write code that still assumes (a), (b), and (c), which actually do not hold in that module.

Violation of (a) shows up in the parser. For instance, in the following examples, we have * not applied to enough arguments:

data A :: * data F :: * -> *

Violation of (b) or (c) show up in the renamer and the typechecker respectively. For instance:

type K = Either * Bool

This will parse differently depending on whether StarIsType is enabled, but it will parse nonetheless. With NoStarIsType it is parsed as a type operator, thus we have ((*) Either Bool). Now there are two cases to consider:

  1. There is no definition of (*) in scope. In this case the renamer will fail to look it up. This is a violation of assumption (b).
  2. There is a definition of the (*) type operator in scope (for example coming from GHC.TypeNats). In this case the user will get a kind mismatch error. This is a violation of assumption (c).

The user might unknowingly be working on a module with NoStarIsType or use * as Type out of habit. So it is important to give a hint whenever an assumption about * is violated. Unfortunately, it is somewhat difficult to deal with (c), so we limit ourselves to (a) and (b).

starInfo generates an appropriate hint to the user depending on the extensions enabled in the module and the name that triggered the error. That is, if we have NoStarIsType and the error is related to * or its Unicode variant, the resulting SDoc will contain a helpful suggestion. Otherwise it is empty.