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

diff --git a/lib/core/collection/abstract_collection.nit b/lib/core/collection/abstract_collection.nit
index aca4fdc..5f9af05 100644
--- a/lib/core/collection/abstract_collection.nit
+++ b/lib/core/collection/abstract_collection.nit
@@ -177,6 +177,21 @@ interface Collection[E]
 		for e in self do if self.count(e) != other.count(e) then return false
 		return true
 	end
+
+	# Does the collection contain at least one element of `other`?
+	#
+	#     assert [1,3,4,2].has_any([1..10])    == true
+	#     assert [1,3,4,2].has_any([5..10])    == false
+	#
+	# Note that the default implementation is general and correct for any lawful Collections.
+	# It is memory-efficient but relies on `has` so may be CPU-inefficient for some kind of collections.
+	fun has_any(other: Collection[nullable Object]): Bool
+	do
+		for o in other do
+			if has(o) then return true
+		end
+		return false
+	end
 end
 
 # Iterators generate a series of elements, one at a time.
@@ -394,6 +409,7 @@ end
 #      assert s.has(b)      ==  true
 interface Set[E]
 	super SimpleCollection[E]
+	super Cloneable
 
 	redef fun has_only(item)
 	do
@@ -456,6 +472,8 @@ interface Set[E]
 		return nhs
 	end
 
+	redef fun clone do return union(self)
+
 	# Returns a new instance of `Set`.
 	#
 	# Depends on the subclass, mainly used for copy services
@@ -794,6 +812,44 @@ interface SequenceRead[E]
 	# REQUIRE `index >= 0 and index < length`
 	fun [](index: Int): E is abstract
 
+	# Return the index-th element but wrap
+	#
+	# Whereas `self[]` requires the index to exists, the `modulo` accessor automatically
+	# wraps overbound and underbouds indexes.
+	#
+	# ~~~
+	# var a = [10,20,30]
+	# assert a.modulo(1) == 20
+	# assert a.modulo(3) == 10
+	# assert a.modulo(-1) == 30
+	# assert a.modulo(-10) == 30
+	# ~~~
+	#
+	# REQUIRE `not_empty`
+	# ENSURE `result == self[modulo_index(index)]`
+	fun modulo(index: Int): E do return self[modulo_index(index)]
+
+	# Returns the real index for a modulo index.
+	#
+	# ~~~
+	# var a = [10,20,30]
+	# assert a.modulo_index(1) == 1
+	# assert a.modulo_index(3) == 0
+	# assert a.modulo_index(-1) == 2
+	# assert a.modulo_index(-10) == 2
+	# ~~~
+	#
+	# REQUIRE `not_empty`
+	fun modulo_index(index: Int): Int
+	do
+		var length = self.length
+		if index >= 0 then
+			return index % length
+		else
+			return length - (-1 - index) % length - 1
+		end
+	end
+
 	# Get the last item.
 	# Is equivalent with `self[length-1]`.
 	#
@@ -853,18 +909,13 @@ interface SequenceRead[E]
 	#     assert a.last_index_of_from(20, 2)   == 1
 	#     assert a.last_index_of_from(20, 1)   == 1
 	#     assert a.last_index_of_from(20, 0)   == -1
-	fun last_index_of_from(item: nullable Object, pos: Int): Int
-	do
-		var res = -1
-		var p = 0
-		var i = iterator
-		while i.is_ok do
-			if p>pos then break
-			if i.item == item then res = p
-			i.next
-			p += 1
+	fun last_index_of_from(item: nullable Object, pos: Int): Int do
+		var i = pos
+		while i >= 0 do
+			if self[i] == item then return i
+			i -= 1
 		end
-		return res
+		return -1
 	end
 
 	# Two sequences are equals if they have the same items in the same order.
@@ -1049,6 +1100,24 @@ interface Sequence[E]
 	# REQUIRE `index >= 0 and index <= length`
 	fun []=(index: Int, item: E) is abstract
 
+	# Set the index-th element but wrap
+	#
+	# Whereas `self[]=` requires the index to exists, the `modulo` accessor automatically
+	# wraps overbound and underbouds indexes.
+	#
+	# ~~~
+	# var a = [10,20,30]
+	# a.modulo(1) = 200
+	# a.modulo(3) = 100
+	# a.modulo(-1) = 300
+	# a.modulo(-10) = 301
+	# assert a == [100, 200, 301]
+	# ~~~
+	#
+	# REQUIRE `not_empty`
+	# ENSURE `self[modulo_index(index)] == value`
+	fun modulo=(index: Int, value: E) do self[modulo_index(index)] = value
+
 	# Insert an element at a given position, following elements are shifted.
 	#
 	#     var a = [10, 20, 30, 40]