AST nodes for function-typed parameters.

dart/frog/leg/tree/unparser.dart

 // Copyright (c) 2011, 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.
 
 class Unparser implements Visitor {
   StringBuffer sb;
   final bool printDebugInfo;
 
   Unparser([this.printDebugInfo = false]);
 
@@ skipping 134 matching lines @@
   visitOperator(Operator node) {
     visitIdentifier(node);
   }
 
   visitReturn(Return node) {
     add(node.beginToken.value);
     if (node.hasExpression) {
       sb.add(' ');
       visit(node.expression);
     }
-    add(node.endToken.value);
+    if (node.endToken !== null) add(node.endToken.value);
   }
 
 
   unparseSendPart(Send node) {
     if (node.isPrefix) {
       visit(node.selector);
     }
     if (node.receiver !== null) {
       visit(node.receiver);
       if (node.selector is !Operator) sb.add('.');
@@ skipping 186 matching lines @@
       sb.add(' ');
     }
     visit(node.name);
     if (node.typeParameters !== null) {
       visit(node.typeParameters);
     }
     visit(node.formals);
     add(node.endToken.value);
   }
 }