lib/standard: introduce *Iterator::finish

Signed-off-by: Jean Privat <jean@pryen.org>

diff --git a/lib/standard/collection/abstract_collection.nit b/lib/standard/collection/abstract_collection.nit
index d2cdb2c..843f8eb 100644 (file)
--- a/lib/standard/collection/abstract_collection.nit
+++ b/lib/standard/collection/abstract_collection.nit
@@ -152,6 +152,16 @@ interface Iterator[E]
 
        # Iterate over `self`
        fun iterator: Iterator[E] do return self
+
+       # 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
 
 # A collection that contains only one item.
@@ -526,6 +536,16 @@ interface MapIterator[K: Object, V]
 
        # Set a new `item` at `key`.
        #fun item=(item: E) is abstract
+
+       # 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
 
 # Iterator on a 'keys' point of view of a map