PrettyPrinter: add an ability to prefix node fields, so instead of:

lib/compiler/implementation/tree/prettyprint.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /**
  * Pretty-prints Node tree in XML-like format.
  *
  * TODO(smok): Add main() to run from command-line to print out tree for given
  * .dart file.
  */
 class PrettyPrinter implements Visitor {
 
   /** String used to represent one level of indent. */
   static final String INDENT = "  ";
 
   StringBuffer sb;
   int depth;
+  // Prefix for the next openNode() invocation for that type.

[Anton Muhin, 2012/06/14 20:32:37]

nit: /** Prefix for the next [:openNode():] invocation for that type */

And what that type means?

[Roman, 2012/06/14 20:47:32]

Done. Reformulated. It's the type of the node to print out.

+  String nextPrefix;
 
   PrettyPrinter() : sb = new StringBuffer(), depth = 0;
 
   /**
    * Adds given string to result string.
    */
   void add(SourceString string) {
     string.printOn(sb);
   }
 
@@ skipping 26 matching lines @@
    */
   void closeNode(String type, [Map params]) {
     depth--;
     addCurrentIndent();
     sb.add("</");
     addTypeWithParams(type, params);
     sb.add(">\n");
   }
 
   void addTypeWithParams(String type, [Map params]) {
+    if (nextPrefix != null) {

[Anton Muhin, 2012/06/14 20:32:37]

nit: !==

[Roman, 2012/06/14 20:47:32]

Done.

+      sb.add("$nextPrefix");

[Anton Muhin, 2012/06/14 20:32:37]

I think simple sb.add(nextPrefix) should work as well.

[Roman, 2012/06/14 20:47:32]

Done.

+      nextPrefix = null;

[Anton Muhin, 2012/06/14 20:32:37]

is it okay to reset it that early, do we want to have the matching closing tag?

[Roman, 2012/06/14 20:47:32]

It may be nice, but not so necessary. And we would have to keep the stack of
current prefixes, I would like to avoid that :)

+    }
     sb.add("${type}");
     if (params != null) {
       // TODO(smok): Escape doublequotes in values.
       params.forEach((k, v) => sb.add(' $k="$v"'));
     }
   }
 
   void addCurrentIndent() {
     for (int i = 0; i < depth; i++) {
       sb.add(INDENT);
@@ skipping 161 matching lines @@
   }
 
   visitReturn(Return node) {
     visitNodeWithChildren(node, "Return");
   }
 
   visitScriptTag(ScriptTag node) {
     visitNodeWithChildren(node, "ScriptTag");
   }
 
+  openSendNodeWithFields(Send node, String type) {
+    openNode(type,

[Anton Muhin, 2012/06/14 20:32:37]

nit: somewhat weird formatting, I'd rather do it like:

openNode(type, {
  "isPrefix": ...,
  "isPostfix": ..
...

[Roman, 2012/06/14 20:47:32]

Done.

+        {"isPrefix" : "${node.isPrefix}", "isPostfix" : "${node.isPostfix}",
+            "isIndex" : "${node.isIndex}"});
+    if (node.receiver !== null) {
+      nextPrefix = "receiver:";

[Anton Muhin, 2012/06/14 20:32:37]

you may want to introduce withPrefix helper, something like:

withPrefix(prefix, action) {
  nextPrefix = prefix;
  action();
}

[Roman, 2012/06/14 20:47:32]

Done.

+      node.receiver.accept(this);
+    }
+    if (node.selector !== null) {
+      nextPrefix = "selector:";
+      node.selector.accept(this);
+    }
+    if (node.argumentsNode !== null) {
+      nextPrefix = "argumentsNode:";
+      node.argumentsNode.accept(this);
+    }
+  }
+
   visitSend(Send node) {
-    visitNodeWithChildren(node, "Send");
+    openSendNodeWithFields(node, "Send");
+    closeNode("Send");
   }
 
   visitSendSet(SendSet node) {
-    visitNodeWithChildren(node, "SendSet");
+    openSendNodeWithFields(node, "SendSet");
+    if (node.assignmentOperator !== null) {
+      nextPrefix = "assignmentOperator:";
+      node.assignmentOperator.accept(this);
+    }
+    closeNode("SendSet");
   }
 
   visitStringInterpolation(StringInterpolation node) {
     visitNodeWithChildren(node, "StringInterpolation");
   }
 
   visitStringInterpolationPart(StringInterpolationPart node) {
     visitNodeWithChildren(node, "StringInterpolationPart");
   }
 
@@ skipping 30 matching lines @@
   }
 
   visitVariableDefinitions(VariableDefinitions node) {
     visitNodeWithChildren(node, "VariableDefinitions");
   }
 
   visitWhile(While node) {
     visitNodeWithChildren(node, "While");
   }
 }