# The special universal most specific type.
#
# This type is intended to be only used internally for type computation or analysis and should not be exposed to the user.
# The bottom type can de used to denote things that are dead (no instance).
#
# Semantically it is the singleton `null.as_notnull`.
# Is also means that `self.as_nullable == null`.
class MBottomType
	super MType
	redef var model
	redef fun to_s do return "bottom"
	redef fun full_name do return "bottom"
	redef fun c_name do return "bottom"
	redef fun as_nullable do return model.null_type
	redef fun as_notnull do return self
	redef fun need_anchor do return false
	redef fun resolve_for(mtype, anchor, mmodule, cleanup_virtual) do return self
	redef fun can_resolve_for(mtype, anchor, mmodule) do return true

	redef fun collect_mclassdefs(mmodule) do return new HashSet[MClassDef]

	redef fun collect_mclasses(mmodule) do return new HashSet[MClass]

	redef fun collect_mtypes(mmodule) do return new HashSet[MClassType]
end