X-Git-Url: http://nitlanguage.org

diff --git a/lib/standard/collection/abstract_collection.nit b/lib/standard/collection/abstract_collection.nit
index 5501290..7320e83 100644
--- a/lib/standard/collection/abstract_collection.nit
+++ b/lib/standard/collection/abstract_collection.nit
@@ -188,7 +188,7 @@ class Container[E]
 	init(e: E) do item = e
 
 	# The stored item
-	var item: E writable
+	var item: E is writable
 end
 
 # This iterator is quite stupid since it is used for only one item.
@@ -202,7 +202,7 @@ private class ContainerIterator[E]
 
 	redef var is_ok: Bool = true
 
-	var _container: Container[E]
+	private var container: Container[E]
 end
 
 # Items can be removed from this collection
@@ -781,7 +781,9 @@ interface Sequence[E]
 	#     var a = [1,2,3]
 	#     a.append([7..9])
 	#     assert a  == [1,2,3,7,8,9]
-	fun append(coll: Collection[E]) do for i in coll do push(i)
+	#
+	# Alias of `add_all`
+	fun append(coll: Collection[E]) do add_all(coll)
 
 	# Remove the last item.
 	#
@@ -801,6 +803,15 @@ interface Sequence[E]
 	#     assert a  == [20,10,1,2,3]
 	fun unshift(e: E) is abstract
 
+	# Add all items of `coll` before the first one.
+	#
+	#     var a = [1,2,3]
+	#     a.prepend([7..9])
+	#     assert a  == [7,8,9,1,2,3]
+	#
+	# Alias of `insert_at(coll, 0)`
+	fun prepend(coll: Collection[E]) do insert_all(coll, 0)
+
 	# Remove the first item.
 	# The second item thus become the first.
 	#
@@ -833,10 +844,30 @@ interface Sequence[E]
 	#     a.insert(100, 2)
 	#     assert a      ==  [10, 20, 100, 30, 40]
 	#
-	# REQUIRE `index >= 0 and index < length`
+	# REQUIRE `index >= 0 and index <= length`
 	# ENSURE `self[index] == item`
 	fun insert(item: E, index: Int) is abstract
 
+	# Insert all elements at a given position, following elements are shifted.
+	#
+	#     var a = [10, 20, 30, 40]
+	#     a.insert_all([100..102], 2)
+	#     assert a      ==  [10, 20, 100, 101, 102, 30, 40]
+	#
+	# REQUIRE `index >= 0 and index <= length`
+	# ENSURE `self[index] == coll.first`
+	fun insert_all(coll: Collection[E], index: Int)
+	do
+		assert index >= 0 and index < length
+		if index == length then
+			add_all(coll)
+		end
+		for c in coll do
+			insert(c, index)
+			index += 1
+		end
+	end
+
 	# Remove the item at `index` and shift all following elements
 	#
 	#     var a = [10,20,30]
@@ -898,7 +929,7 @@ private class CoupleMapIterator[K: Object, E]
 		_iter.next
 	end
 
-	var _iter: Iterator[Couple[K,E]]
+	private var iter: Iterator[Couple[K,E]]
 
 	init(i: Iterator[Couple[K,E]]) do _iter = i
 end
@@ -909,10 +940,10 @@ end
 class Couple[F, S]
 
 	# The first element of the couple.
-	var first: F writable
+	var first: F is writable
 
 	# The second element of the couple.
-	var second: S writable
+	var second: S is writable
 
 	# Create a new instance with a first and a second object.
 	init(f: F, s: S)