# The type of the only value null
#
# The is only one null type per model, see `MModel::null_type`.
class MNullType
	super MType
	redef var model
	redef fun to_s do return "null"
	redef fun full_name do return "null"
	redef fun c_name do return "null"
	redef fun as_nullable do return self

	redef var as_notnull: MBottomType = new MBottomType(model) is lazy
	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