ghc-7.0.2: The GHC API




GHC uses several kinds of name internally:

  • OccName: see OccName
  • RdrName.RdrName: see RdrName
  • Name is the type of names that have had their scoping and binding resolved. They have an OccName but also a Unique that disambiguates Names that have the same OccName and indeed is used for all Name comparison. Names also contain information about where they originated from, see Name
  • Id.Id: see Id
  • Var.Var: see Var

Names are one of:

  • External, if they name things declared in other modules. Some external Names are wired in, i.e. they name primitives defined in the compiler itself
  • Internal, if they name things in the module being compiled. Some internal Names are system names, if they are names manufactured by the compiler


The main types

data Name Source

A unique, unambigious name for something, containing information about where that thing originated.

data BuiltInSyntax Source

BuiltInSyntax is for things like (:), [] and tuples, which have special syntactic forms. They aren't in scope as such.



Creating Names

mkInternalName :: Unique -> OccName -> SrcSpan -> NameSource

Create a name which is (for now at least) local to the current module and hence does not need a Module to disambiguate it from other Names

mkSystemName :: Unique -> OccName -> NameSource

Create a name brought into being by the compiler

mkFCallName :: Unique -> String -> NameSource

Make a name for a foreign call

mkIPName :: Unique -> OccName -> NameSource

Make the name of an implicit parameter

mkExternalName :: Unique -> Module -> OccName -> SrcSpan -> NameSource

Create a name which definitely originates in the given module

mkWiredInName :: Module -> OccName -> Unique -> TyThing -> BuiltInSyntax -> NameSource

Create a name which is actually defined by the compiler itself

Manipulating and deconstructing Names

localiseName :: Name -> NameSource

Make the Name into an internal name, regardless of what it was to begin with

Predicates on Names

Class NamedThing and overloaded friends

class NamedThing a whereSource

A class allowing convenient access to the Name of various datatypes

module OccName