nitcc: add new PoV Node::depth

Signed-off-by: Jean Privat <jean@pryen.org>

diff --git a/lib/nitcc_runtime.nit b/lib/nitcc_runtime.nit
index 3aa2810..bf778cf 100644 (file)
--- a/lib/nitcc_runtime.nit
+++ b/lib/nitcc_runtime.nit
@@ -306,6 +306,9 @@ 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 +365,42 @@ abstract class Node
        end
 end
 
+private class DephCollection
+       super NaiveCollection[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 +601,7 @@ 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)