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

diff --git a/lib/trees/bintree.nit b/lib/trees/bintree.nit
index b689700..6b6b91c 100644
--- a/lib/trees/bintree.nit
+++ b/lib/trees/bintree.nit
@@ -93,6 +93,7 @@ class BinTreeMap[K: Comparable, E]
 		return res.value
 	end
 
+	# Search `key` in `from` and its children nodes.
 	protected fun search_down(from: N, key: K): nullable N do
 		var cmp = key <=> from.key
 		if cmp == 0 then return from
@@ -115,6 +116,7 @@ class BinTreeMap[K: Comparable, E]
 		return min_from(root.as(not null)).value
 	end
 
+	# Get the left-most child from `node`.
 	protected fun min_from(node: N): N do
 		if node.left == null then return node
 		return min_from(node.left.as(not null))
@@ -131,6 +133,7 @@ class BinTreeMap[K: Comparable, E]
 		return max_from(root.as(not null)).value
 	end
 
+	# Get the right-most child from `node`.
 	protected fun max_from(node: N): N do
 		if node.right == null then return node
 		return max_from(node.right.as(not null))
@@ -148,6 +151,7 @@ class BinTreeMap[K: Comparable, E]
 		insert_node(new BinTreeNode[K, E](key, item))
 	end
 
+	# Add `node` in the tree.
 	protected fun insert_node(node: N) do
 		len += 1
 		if root == null then
@@ -244,11 +248,13 @@ class BinTreeMap[K: Comparable, E]
 
 	# Perform left rotation on `node`
 	#
+	# ~~~raw
 	#     N             Y
 	#    / \     >     / \
 	#   a   Y         N   c
 	#      / \   <   / \
 	#     b   c     a   b
+	# ~~~
 	#
 	protected fun rotate_left(node: N) do
 		var y = node.right
@@ -270,11 +276,13 @@ class BinTreeMap[K: Comparable, E]
 
 	# Perform right rotation on `node`
 	#
+	# ~~~raw
 	#     N             Y
 	#    / \     >     / \
 	#   a   Y         N   c
 	#      / \   <   / \
 	#     b   c     a   b
+	# ~~~
 	#
 	protected fun rotate_right(node: N) do
 		var y = node.left
@@ -307,6 +315,7 @@ class BinTreeMap[K: Comparable, E]
 		return sorted
 	end
 
+	# Sort the tree from `node` and place results in `sorted`.
 	protected fun sort_down(node: N, sorted: Array[E]) do
 		if node.left != null then sort_down(node.left.as(not null), sorted)
 		sorted.add(node.value)
@@ -319,6 +328,7 @@ class BinTreeMap[K: Comparable, E]
 		return "[{print_tree(root)}]"
 	end
 
+	# Print the tree starting from `node`.
 	protected fun print_tree(node: N): String do
 		var s = new FlatBuffer
 		s.append(node.to_s)
@@ -329,14 +339,15 @@ class BinTreeMap[K: Comparable, E]
 
 	redef fun show_dot do
 		assert not_empty: root != null
-		var f = new OProcess("dot", "-Txlib")
+		var f = new ProcessWriter("dot", "-Txlib")
 		f.write "digraph \{\n"
 		dot_down(root.as(not null), f)
 		f.write "\}\n"
 		f.close
 	end
 
-	protected fun dot_down(node: N, f: OProcess) do
+	# Translate the tree in dot format starting from `node`.
+	protected fun dot_down(node: N, f: ProcessWriter) do
 		if node.left != null then dot_down(node.left.as(not null), f)
 		f.write node.to_dot
 		if node.right != null then dot_down(node.right.as(not null), f)
@@ -367,41 +378,37 @@ end
 class BinTreeNode[K: Comparable, E]
 	super TreeNode[K, E]
 
-	private var prev: nullable BinTreeNode[K, E]
-	private var next: nullable BinTreeNode[K, E]
+	private var prev: nullable BinTreeNode[K, E] = null
+	private var next: nullable BinTreeNode[K, E] = null
 
-	redef type SELF: BinTreeNode[K, E]
-
-	init(key: K, item: E) do
-		super(key, item)
-	end
+	redef type N: BinTreeNode[K, E]
 
-	private var left_node: nullable SELF = null
+	private var left_node: nullable N = null
 
 	# `left` tree node child (null if node has no left child)
-	fun left: nullable SELF do return left_node
+	fun left: nullable N do return left_node
 
 	# set `left` child for this node (or null if left no child)
 	# ENSURE: node.key < key (only if node != null)
-	fun left=(node: nullable SELF) do
+	fun left=(node: nullable N) do
 		#assert node != null implies node.key < key
 		left_node = node
 	end
 
-	private var right_node: nullable SELF = null
+	private var right_node: nullable N = null
 
 	# `right` tree node child (null if node has no right child)
-	fun right: nullable SELF do return right_node
+	fun right: nullable N do return right_node
 
 	# set `right` child for this node (or null if right no child)
 	# ENSURE: node.key < key (only if node != null)
-	fun right=(node: nullable SELF) do
+	fun right=(node: nullable N) do
 		#assert node != null implies node.key > key
 		right_node = node
 	end
 
 	# `parent` of the `parent` of this node (null if root)
-	fun grandparent: nullable SELF do
+	fun grandparent: nullable N do
 		if parent == null then
 			return null
 		else
@@ -411,7 +418,7 @@ class BinTreeNode[K: Comparable, E]
 
 	# Other child of the `grandparent`
 	# `left` or `right` depends on the position of the current node against its parent
-	fun uncle: nullable SELF do
+	fun uncle: nullable N do
 		var g = grandparent
 		if g == null then
 			return null
@@ -426,7 +433,7 @@ class BinTreeNode[K: Comparable, E]
 
 	# Other child of the parent
 	# `left` or `right` depends on the position of the current node against its parent
-	fun sibling: nullable SELF do
+	fun sibling: nullable N do
 		if parent == null then
 			return null
 		else if self == parent.left then
@@ -444,11 +451,10 @@ end
 private class BinTreeMapIterator[K: Comparable, E]
 	super MapIterator[K, E]
 
-	var current: nullable BinTreeNode[K, E]
+	var tree: BinTreeMap[K, E]
+	var current: nullable BinTreeNode[K, E] = null
 
-	init(tree: BinTreeMap[K, E]) do
-		current = tree.first_node
-	end
+	init do current = tree.first_node
 
 	redef fun is_ok do return not current == null
 	redef fun next do current = current.next