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

diff --git a/lib/trees/bintree.nit b/lib/trees/bintree.nit
index 37d8c87..447a33f 100644
--- a/lib/trees/bintree.nit
+++ b/lib/trees/bintree.nit
@@ -36,6 +36,7 @@ import abstract_tree
 #  * delete average O(lg n) worst O(n)
 #
 # Usage:
+#
 #     var tree = new BinTreeMap[Int, String]
 #     tree[1] = "n1"
 #     assert tree.min == "n1"
@@ -64,7 +65,7 @@ class BinTreeMap[K: Comparable, E]
 	#     assert not tree.has_key(0)
 	#     assert tree.has_key(2)
 	#     assert not tree.has_key(6)
-	redef fun has_key(key: K): Bool do
+	redef fun has_key(key) do
 		if is_empty then return false
 		var res = search_down(root.as(not null), key)
 		if res != null then
@@ -85,7 +86,7 @@ class BinTreeMap[K: Comparable, E]
 	#     assert tree[1] == "n1"
 	#     assert tree.has_key(1)
 	#     assert tree[2] == "n2"
-	redef fun [](key: K): E do
+	redef fun [](key) do
 		assert not_empty: not is_empty
 		if cache_node != null and cache_node.key == key then return cache_node.value
 		var res = search_down(root.as(not null), key)
@@ -94,7 +95,8 @@ class BinTreeMap[K: Comparable, E]
 	end
 
 	# Search `key` in `from` and its children nodes.
-	protected fun search_down(from: N, key: K): nullable N do
+	protected fun search_down(from: N, key: nullable Object): nullable N do
+		if not key isa Comparable then return null
 		var cmp = key <=> from.key
 		if cmp == 0 then return from
 		if from.left != null and cmp < 0 then
@@ -339,7 +341,7 @@ 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"
@@ -347,7 +349,7 @@ class BinTreeMap[K: Comparable, E]
 	end
 
 	# Translate the tree in dot format starting from `node`.
-	protected fun dot_down(node: N, f: OProcess) do
+	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)
@@ -378,15 +380,11 @@ 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 N: BinTreeNode[K, E]
 
-	init(key: K, item: E) do
-		super(key, item)
-	end
-
 	private var left_node: nullable N = null
 
 	# `left` tree node child (null if node has no left child)
@@ -455,11 +453,10 @@ 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