GHC.Builtin.Utils

The GHC.Builtin.Utils interface to the compiler's prelude knowledge.

This module serves as the central gathering point for names which the compiler knows something about. This includes functions for,

• discerning whether a Name is known-key
• given a Unique, looking up its corresponding known-key Name

See Note [Known-key names] and Note [About wired-in things] for information about the two types of prelude things in GHC.

Known-key names

isKnownKeyName :: Name -> Bool

Is a Name known-key?

lookupKnownKeyName :: Unique -> Maybe Name

Given a Unique lookup its associated Name if it corresponds to a known-key thing.

lookupKnownNameInfo :: Name -> SDoc

Given a Unique lookup any associated arbitrary SDoc's to be displayed by GHCi's ':info' command.

Internal use

knownKeyNames is exported to seed the original name cache only; if you find yourself wanting to look at it you might consider using lookupKnownKeyName or isKnownKeyName.

knownKeyNames :: [Name]

This list is used to ensure that when you say "Prelude.map" in your source code, or in an interface file, you get a Name with the correct known key (See Note [Known-key names] in GHC.Builtin.Names)

Miscellaneous

wiredInIds :: [Id]

ghcPrimIds :: [Id]

ghcPrimExports :: [IfaceExport]

ghcPrimDeclDocs :: Docs

Random other things

maybeCharLikeCon :: DataCon -> Bool

maybeIntLikeCon :: DataCon -> Bool

Class categories

isNumericClass :: Class -> Bool

isStandardClass :: Class -> Bool