Introduce renameNodes helper to factor out common pattern.

lib/compiler/implementation/dart_backend/renamer.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.
 
 /**
  * Renames only top-level elements that would let to ambiguity if not renamed.
  * TODO(smok): Make sure that top-level fields are correctly renamed.
  */
 void renamePlaceholders(
     Compiler compiler,
@@ skipping 32 matching lines @@
     if (isDartCoreLib(compiler, library)) {
       final prefix =
           imports.putIfAbsent(library, () => generateUniqueName('p'));
       return '$prefix.$originalName';
     }
 
     return getName(library, originalName,
                    () => generateUniqueName(originalName));
   }
 
-  placeholderCollector.nullNodes.forEach((Node node) {
-    renames[node] = '';
-  });
-  placeholderCollector.unresolvedNodes.forEach((Node node) {
-    renames[node] = generateUniqueName('Unresolved');
-  });
+  renameNodes(Collection<Node> nodes, renamer) {
+    for (Node node in nodes) {
+      renames[node] = renamer(node);
+    }
+  }
+
+  renameNodes(placeholderCollector.nullNodes, (_) => '');

[Roman, 2012/08/21 08:02:44]

did you use '_' instead of 'node' to save 3 chars and not confuse reader? same
below

[Anton Muhin, 2012/08/21 09:11:10]

That's the common idiom to mark unused argument.  There is even a proposal to
make supported by language to allow (_, _, _, x) => x.

On 2012/08/21 08:02:44, Roman wrote:

+  renameNodes(placeholderCollector.unresolvedNodes,
+      (_) => generateUniqueName('Unresolved'));
   placeholderCollector.elementNodes.forEach(
       (Element element, Set<Node> nodes) {
         String renamedElement = renameElement(element);
-        nodes.forEach((Node node) {
-          renames[node] = renamedElement;
-        });
+        renameNodes(nodes, (_) => renamedElement);
   });
   placeholderCollector.localPlaceholders.forEach(
       (FunctionElement element, Set<LocalPlaceholder> localPlaceholders) {
         // TODO(smok): Check for conflicts with class fields and take usages
         // into account.
         localPlaceholders.forEach((LocalPlaceholder placeholder) {
-          placeholder.nodes.forEach((Node node) {
-            renames[node] = placeholder.identifier;
-          });
+          renameNodes(placeholder.nodes, (_) => placeholder.identifier);
         });
       });
   placeholderCollector.privateNodes.forEach(
       (LibraryElement library, Set<Identifier> nodes) {
-        nodes.forEach((Identifier node) {
-          renames[node] =
-              renamePrivateIdentifier(library, node.source.slowToString());
-        });
+        renameNodes(nodes, (node) =>
+            renamePrivateIdentifier(library, node.source.slowToString()));
   });
 }
 
 typedef String Generator(String originalName, bool isForbidden(String name));
 
 /** Always tries to return original identifier name unless it is forbidden. */
 String conservativeGenerator(
     String originalName, bool isForbidden(String name)) {
   String newName = originalName;
   while (isForbidden(newName)) {
@@ skipping 29 matching lines @@
     int length = alphabet.length;
     StringBuffer resultBuilder = new StringBuffer();
     while (index >= length) {
       resultBuilder.add(alphabet[index % length]);
       index ~/= length;
     }
     resultBuilder.add(alphabet[index]);
     return resultBuilder.toString();
   }
 }