# Provides a better API but mainly the same content as AExternCalls
class ForeignCallbackSet
	# set of imported functions, cached to avoid repetitions
	var callbacks: Set[ MExplicitCall ] = new HashSet[ MExplicitCall ]

	# set of imported functions, cached to avoid repetitions
	var supers: Set[ MExplicitSuper ] = new HashSet[ MExplicitSuper ]

	# set of relevant types, cached to avoid repetitions
	var types: Set[ MType ] = new HashSet[ MType ]

	# set of imported casts and as, cached to avoid repetitions
	var casts: Set[ MExplicitCast ] = new HashSet[ MExplicitCast ]

	# Utility function, must be called only when all other maps are filled
	private var all_cached: nullable Set[NitniCallback] = null
	fun all: Set[NitniCallback]
	do
		var cached = all_cached
		if cached != null then return cached

		var set = new HashSet[NitniCallback]
		set.add_all(callbacks)
		set.add_all(supers)
		set.add_all(types)
		set.add_all(casts)
		
		self.all_cached = set
		return set
	end

	# Integrate content from the `other` set into this one
	fun join(other: ForeignCallbackSet)
	do
		callbacks.add_all( other.callbacks )
		supers.add_all( other.supers )
		types.add_all( other.types )
		casts.add_all( other.casts )
	end
end