---

yaml
---
r: 128669
b: refs/heads/try
c: 8a80e0f
h: refs/heads/master
i:
  128667: 74b54bc
v: v3

Author: pnkfelix

[refs]

@@ -2,7 +2,7 @@
 refs/heads/master: 07d86b46a949a94223da714e35b343243e4ecce4
 refs/heads/snap-stage1: e33de59e47c5076a89eadeb38f4934f58a3618a6
 refs/heads/snap-stage3: a86d9ad15e339ab343a12513f9c90556f677b9ca
-refs/heads/try: a9b1a3b40f29795d5f049e342ec4a494e83125e9
+refs/heads/try: 8a80e0fdab93cb6fb9eeb592857b8eeb35d14f15
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b
 refs/heads/try2: 147ecfdd8221e4a4d4e090486829a06da1e0ca3c

branches/try/src/libsyntax/ast_map/mod.rs

@@ -21,6 +21,7 @@ use util::small_vector::SmallVector;
 use std::cell::RefCell;
 use std::fmt;
 use std::gc::{Gc, GC};
+use std::io::IoResult;
 use std::iter;
 use std::slice;
 
@@ -819,6 +820,34 @@ pub fn map_decoded_item<F: FoldOps>(map: &Map,
     ii
 }
 
+pub trait NodePrinter {
+    fn print_node(&mut self, node: &Node) -> IoResult<()>;
+}
+
+impl<'a> NodePrinter for pprust::State<'a> {
+    fn print_node(&mut self, node: &Node) -> IoResult<()> {
+        match *node {
+            NodeItem(a)        => self.print_item(&*a),
+            NodeForeignItem(a) => self.print_foreign_item(&*a),
+            NodeTraitMethod(a) => self.print_trait_method(&*a),
+            NodeMethod(a)      => self.print_method(&*a),
+            NodeVariant(a)     => self.print_variant(&*a),
+            NodeExpr(a)        => self.print_expr(&*a),
+            NodeStmt(a)        => self.print_stmt(&*a),
+            NodePat(a)         => self.print_pat(&*a),
+            NodeBlock(a)       => self.print_block(&*a),
+            NodeLifetime(a)    => self.print_lifetime(&*a),
+
+            // these cases do not carry enough information in the
+            // ast_map to reconstruct their full structure for pretty
+            // printing.
+            NodeLocal(_)       => fail!("cannot print isolated Local"),
+            NodeArg(_)         => fail!("cannot print isolated Arg"),
+            NodeStructCtor(_)  => fail!("cannot print isolated StructCtor"),
+        }
+    }
+}
+
 fn node_id_to_string(map: &Map, id: NodeId) -> String {
     match map.find(id) {
         Some(NodeItem(item)) => {