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

diff --git a/src/parser/xss/nodes.xss b/src/parser/xss/nodes.xss
index 3d59406..8b0d044 100644
--- a/src/parser/xss/nodes.xss
+++ b/src/parser/xss/nodes.xss
@@ -35,7 +35,7 @@ $ end template
 $ template make_nodes()
 redef class PNode
 	# Parent of the node in the AST
-	readable writable attr _parent: PNode 
+	readable writable attr _parent: nullable PNode
 
 	# Remove a child from the AST
 	meth remove_child(child: PNode)
@@ -44,7 +44,7 @@ redef class PNode
 	end
 
 	# Replace a child with an other node in the AST
-	meth replace_child(old_child: PNode, new_child: PNode) is abstract
+	meth replace_child(old_child: PNode, new_child: nullable PNode) is abstract
 
 	# Replace itself with an other node in the AST
 	meth replace_with(node: PNode)
@@ -65,6 +65,9 @@ redef class PNode
 	# Give a human readable location of the node.
 	meth locate: String is abstract
 
+	# Return only the line number of the node
+	meth line_number: Int is abstract
+
 	# Debug method: output a message prefixed with the location.
 	meth printl(str: String)
 	do
@@ -75,26 +78,31 @@ end
 redef class Token
 	redef meth visit_all(v: Visitor) do end
 	redef meth visit_all_reverse(v: Visitor) do end
-	redef meth replace_child(old_child: PNode, new_child: PNode) do end
+	redef meth replace_child(old_child: PNode, new_child: nullable PNode) do end
 
 	redef meth locate: String
 	do
 		return "{filename}:{line},{pos}"
 	end
+
+	redef meth line_number do return line
 end
 
 redef class Prod
 	# The first token of the production node
-	readable writable attr _first_token: Token 
+	readable writable attr _first_token: nullable Token
 
 	# The last token of the production node
-	readable writable attr _last_token: Token 
+	readable writable attr _last_token: nullable Token
 
 	redef meth locate: String
 	do
 		if first_token == null then
 			return "????"
 		end
+		if last_token == null then
+			return "{first_token.locate}--????"
+		end
 		var lastpos = last_token.pos + last_token.text.length - 1
 		if first_token.line == last_token.line then
 			return "{first_token.locate}--{lastpos}"
@@ -104,11 +112,20 @@ redef class Prod
 	end
 
 	redef meth replace_with(n: PNode)
+        do
+                super
+                assert n isa Prod
+                n.first_token = first_token
+                n.last_token = last_token
+        end
+
+	redef meth line_number
 	do
-		super
-		assert n isa Prod
-		n.first_token = first_token
-		n.last_token = last_token
+		if first_token != null then
+			return first_token.line
+		else
+			return 0
+		end
 	end
 end
 
@@ -117,7 +134,7 @@ class Visitor
         # Ask the visitor to visit a given node.
         # Usually automatically called by visit_all* methods.
         # Concrete visitors should redefine this method.
-        meth visit(e: PNode) is abstract
+        meth visit(e: nullable PNode) is abstract
 end
 
 $ end template