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

diff --git a/lib/neo4j/graph/sequential_id.nit b/lib/neo4j/graph/sequential_id.nit
index 3b3559a..939ed88 100644
--- a/lib/neo4j/graph/sequential_id.nit
+++ b/lib/neo4j/graph/sequential_id.nit
@@ -36,6 +36,14 @@ private import pipeline
 # assert b["id"] == 2
 # assert c["id"] == 4
 # assert nodes.to_a == [a, b, c]
+# assert nodes.length == 3
+#
+# nodes.compact
+# assert a["id"] == 1
+# assert b["id"] == 2
+# assert c["id"] == 3
+# assert nodes.to_a == [a, b, c]
+# assert nodes.length == 3
 # ~~~
 class SequentialNodeCollection
 	super NeoNodeCollection
@@ -44,16 +52,27 @@ class SequentialNodeCollection
 
 	private var nodes = new Array[nullable NeoNode]
 
+	redef var length = 0
+
 	redef fun iterator do return new NullSkipper[NeoNode](self.nodes.iterator)
 
+	redef fun [](id) do return nodes[id].as(NeoNode)
+
 	redef fun get_or_null(id) do
 		if id < 0 or id > nodes.length then return null
 		return nodes[id]
 	end
 
+	redef fun has_id(id) do
+		return id >= 0 and id < nodes.length and nodes[id] isa NeoNode
+	end
+
+	redef fun enlarge(cap) do nodes.enlarge(cap)
+
 	redef fun register(node) do
 		nodes.add node
 		id_of(node) = nodes.length
+		length += 1
 	end
 
 	redef fun add(node) do
@@ -65,15 +84,33 @@ class SequentialNodeCollection
 			sys.stderr.write "The local ID must be greater or equal to 0. Got {id}.\n"
 		end
 		# Pad with nulls.
+		nodes.enlarge(id)
 		var delta = id - nodes.length
 		while delta > 0 do
 			nodes.add null
 			delta -= 1
 		end
 		nodes[id] = node
+		length += 1
 	end
 
 	redef fun remove_at(id) do
 		nodes[id] = null
+		length -= 1
+	end
+
+	redef fun clear do
+		nodes.clear
+		length = 0
+	end
+
+	redef fun compact do
+		var i = iterator
+
+		nodes = new Array[nullable NeoNode]
+		for n in i do
+			nodes.add n
+			id_of(n) = nodes.length
+		end
 	end
 end