# Iterators for Map.
interface MapIterator[K, V]
	# The current item.
	# Require `is_ok`.
	fun item: V is abstract

	# The key of the current item.
	# Require `is_ok`.
	fun key: K is abstract

	# Jump to the next item.
	# Require `is_ok`.
	fun next is abstract

	# Is there a current item ?
	fun is_ok: Bool is abstract

	# Set a new `item` at `key`.
	#fun item=(item: E) is abstract

	# Pre-iteration hook.
	#
	# Used to inform `self` that the iteration is starting.
	# Specific iterators can use this to prepare some resources.
	#
	# Is automatically invoked at the beginning of `for` structures.
	#
	# Do nothing by default.
	fun start do end

	# Post-iteration hook.
	#
	# Used to inform `self` that the iteration is over.
	# Specific iterators can use this to free some resources.
	#
	# Is automatically invoked at the end of `for` structures.
	#
	# Do nothing by default.
	fun finish do end
end