Some enhancements of PrettyPrinter for NodeList, LiteralList.

lib/compiler/implementation/tree/prettyprint.dart

Index: lib/compiler/implementation/tree/prettyprint.dart
diff --git a/lib/compiler/implementation/tree/prettyprint.dart b/lib/compiler/implementation/tree/prettyprint.dart
index 3baa3926c40c4aa288ce0929c25eacbb451eef9e..f691e9fcc9a96558a6cbcf27cfe7209a52d3d534 100644
--- a/lib/compiler/implementation/tree/prettyprint.dart
+++ b/lib/compiler/implementation/tree/prettyprint.dart
@@ -70,7 +70,14 @@ class PrettyPrinter implements Visitor {
     sb.add("${type}");
     if (params != null) {
       // TODO(smok): Escape doublequotes in values.
-      params.forEach((k, v) => sb.add(' $k="$v"'));
+      params.forEach((k, v) {
+        sb.add(' $k=');
+        if (v !== null) {
+          sb.add('"$v"');
+        } else {
+          sb.add('null');
+        }
+      });
     }
   }
 
@@ -192,8 +199,16 @@ class PrettyPrinter implements Visitor {
     visitLiteral(node, "LiteralInt");
   }
 
+  /** Returns token string value or [null] if token is [null]. */
+  tokenToStringOrNull(Token token) => token === null ? null : token.stringValue;
+
   visitLiteralList(LiteralList node) {
-    visitNodeWithChildren(node, "LiteralList");
+    openNode("LiteralList", {
+      "constKeyword" : tokenToStringOrNull(node.constKeyword)
+    });
+    visitWithPrefix(node.type, "type:");
+    visitWithPrefix(node.elements, "elements:");
+    closeNode("LiteralList");
   }
 
   visitLiteralMap(LiteralMap node) {
@@ -225,10 +240,17 @@ class PrettyPrinter implements Visitor {
   }
 
   visitNodeList(NodeList node) {
+    var params = {
+        "delimiter" :
+            node.delimiter !== null ? node.delimiter.stringValue : null,
+        "beginToken" : tokenToStringOrNull(node.getBeginToken()),
+        "endToken" : tokenToStringOrNull(node.getEndToken())};
     if (node.nodes.toList().length == 0) {
-      openAndCloseNode("NodeList");
+      openAndCloseNode("NodeList", params);
     } else {
-      visitNodeWithChildren(node, "NodeList");
+      openNode("NodeList", params);
+      node.visitChildren(this);
+      closeNode("NodeList");
     }
   }
 
@@ -241,11 +263,12 @@ class PrettyPrinter implements Visitor {
   }
 
   visitReturn(Return node) {
-    var beginToken =
-        node.beginToken !== null ? node.beginToken.stringValue : "null";
-    var endToken = node.endToken !== null ? node.endToken.stringValue : "null";
+    var beginToken = node.getBeginToken() !== null
+        ? node.getBeginToken().stringValue : "null";
+    var endToken = node.getEndToken() !== null
+        ? node.getEndToken().stringValue : "null";
     openNode("Return", {"beginToken" : beginToken, "endToken" : endToken});
-    if (node.hasExpression) visitWithPrefix(node.expression, "expression:");
+    visitWithPrefix(node.expression, "expression:");
     closeNode("Return");
   }
 
@@ -255,6 +278,7 @@ class PrettyPrinter implements Visitor {
 
   /** Custom helper to visit given node and print its type with prefix. */
   visitWithPrefix(Node node, String prefix) {
+    if (node === null) return;
     nextTypePrefix = prefix;
     node.accept(this);
   }
@@ -265,10 +289,9 @@ class PrettyPrinter implements Visitor {
         "isPostfix" : "${node.isPostfix}",
         "isIndex" : "${node.isIndex}"
     });
-    if (node.receiver !== null) visitWithPrefix(node.receiver, "receiver:");
-    if (node.selector !== null) visitWithPrefix(node.selector, "selector:");
-    if (node.argumentsNode !== null)
-        visitWithPrefix(node.argumentsNode, "argumentsNode:");
+    visitWithPrefix(node.receiver, "receiver:");
+    visitWithPrefix(node.selector, "selector:");
+    visitWithPrefix(node.argumentsNode, "argumentsNode:");
   }
 
   visitSend(Send node) {
@@ -278,8 +301,7 @@ class PrettyPrinter implements Visitor {
 
   visitSendSet(SendSet node) {
     openSendNodeWithFields(node, "SendSet");
-    if (node.assignmentOperator !== null)
-        visitWithPrefix(node.assignmentOperator, "assignmentOperator:");
+    visitWithPrefix(node.assignmentOperator, "assignmentOperator:");
     closeNode("SendSet");
   }
 
@@ -324,7 +346,14 @@ class PrettyPrinter implements Visitor {
   }
 
   visitVariableDefinitions(VariableDefinitions node) {
-    visitNodeWithChildren(node, "VariableDefinitions");
+    openNode("VariableDefinitions", {
+      "beginToken" : "${node.getBeginToken().stringValue}",
+      "endToken" : "${node.getEndToken().stringValue}"
+    });
+    visitWithPrefix(node.type, "type:");
+    visitWithPrefix(node.modifiers, "modifiers:");
+    visitWithPrefix(node.definitions, "definitions:");
+    closeNode("VariableDefinitions");
   }
 
   visitWhile(While node) {