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

diff --git a/lib/nitcc_runtime.nit b/lib/nitcc_runtime.nit
index 3aa2810..1342c59 100644
--- a/lib/nitcc_runtime.nit
+++ b/lib/nitcc_runtime.nit
@@ -186,12 +186,14 @@ abstract class Lexer
 				last_state = state
 			end
 			var c
+			var next
 			if pos >= length then
 				c = '\0'
+				next = null
 			else
 				c = text[pos]
+				next = state.trans(c)
 			end
-			var next = state.trans(c)
 			if next == null then
 				if pos_start < length then
 					if last_state == null then
@@ -306,6 +308,9 @@ abstract class Node
 	# A point of view on the direct children of the node
 	fun children: SequenceRead[nullable Node] is abstract
 
+	# A point of view of a depth-first visit of all non-null children
+	var depth: Collection[Node] = new DephCollection(self)
+
 	# Visit all the children of the node with the visitor `v`
 	protected fun visit_children(v: Visitor)
 	do
@@ -362,6 +367,42 @@ abstract class Node
 	end
 end
 
+private class DephCollection
+	super Collection[Node]
+	var node: Node
+	redef fun iterator do return new DephIterator([node].iterator)
+end
+
+private class DephIterator
+	super Iterator[Node]
+	var stack = new List[Iterator[nullable Node]]
+
+	init(i: Iterator[nullable Node])
+	do
+		stack.add i
+	end
+
+	redef fun is_ok do return not stack.is_empty
+	redef fun item do return stack.last.item.as(not null)
+	redef fun next
+	do
+		var i = stack.last
+		stack.push i.item.children.iterator
+		i.next
+		while is_ok do
+			if not stack.last.is_ok then
+				stack.pop
+				continue
+			end
+			if stack.last.item == null then
+				stack.last.next
+				continue
+			end
+			return
+		end
+	end
+end
+
 # A token produced by the lexer and used in a syntactic tree
 abstract class NToken
 	super Node
@@ -562,7 +603,7 @@ abstract class TestParser
 			tpv.enter_visit(n)
 			n = n.error_tree
 		else
-			print "ROOT: {n} (see {astout} and {astdotout})"
+			print "ROOT: {n}; {n.depth.length} nodes (see {astout} and {astdotout})"
 		end
 		tpv.enter_visit(n)
 		n.to_dot(astdotout)