First step toward fixing cascades (issue 5062)

compiler/java/com/google/dart/compiler/ast/DartCascadeExpression.java

Index: compiler/java/com/google/dart/compiler/ast/DartCascadeExpression.java
===================================================================
--- compiler/java/com/google/dart/compiler/ast/DartCascadeExpression.java	(revision 0)
+++ compiler/java/com/google/dart/compiler/ast/DartCascadeExpression.java	(revision 0)
@@ -0,0 +1,85 @@
+// 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.
+
+package com.google.dart.compiler.ast;
+
+import java.util.List;
+
+/**
+ * Instances of the class {@code DartCascadeExpression} represent a sequence of cascaded expressions:
+ * expressions that share a common target. There are three kinds of expressions that can be used in
+ * a cascade expression: {@link DartArrayAccess}, {@link DartMethodInvocation} and {@link DartPropertyAccess}.
+ * 
+ * <pre>
+ * cascadeExpression ::=
+ *     {@link DartExpression conditionalExpression} cascadeSection*
+ * 
+ * cascadeSection ::=
+ *     '..'  (cascadeSelector arguments*) (assignableSelector arguments*)* (assignmentOperator expressionWithoutCascade)?
+ * 
+ * cascadeSelector ::=
+ *     '[ ' expression '] '
+ *   | identifier
+ * </pre>
+ */
+public class DartCascadeExpression extends DartExpression {
+  /**
+   * The target of the cascade sections.
+   */
+  private DartExpression target;
+
+  /**
+   * The cascade sections sharing the common target.
+   */
+  private NodeList<DartExpression> cascadeSections = new NodeList<DartExpression>(this);

[scheglov, 2012/09/27 22:38:43]

Just "sections"?
We don't use "invocationArguments" or "constructorArguments" or "cascadeTarget".

[Brian Wilkerson, 2012/09/28 15:54:39]

I thought about that, but it seemed kind of generic. I really don't like either
name and think we should have better terminology, but that's how the grammar
refers to them. I can change it if you feel strongly about it.

+
+  /**
+   * Initialize a newly created cascade expression.
+   * 
+   * @param target the target of the cascade sections
+   * @param cascadeSections the cascade sections sharing the common target
+   */
+  public DartCascadeExpression(DartExpression target, List<DartExpression> cascadeSections) {
+    this.target = becomeParentOf(target);
+    this.cascadeSections.addAll(cascadeSections);
+  }
+
+  @Override
+  public <R> R accept(ASTVisitor<R> visitor) {
+    return visitor.visitCascadeExpression(this);
+  }
+
+  /**
+   * Return the cascade sections sharing the common target.
+   * 
+   * @return the cascade sections sharing the common target
+   */
+  public NodeList<DartExpression> getCascadeSections() {
+    return cascadeSections;
+  }
+
+  /**
+   * Return the target of the cascade sections.
+   * 
+   * @return the target of the cascade sections
+   */
+  public DartExpression getTarget() {
+    return target;
+  }
+
+  /**
+   * Set the target of the cascade sections to the given expression.
+   * 
+   * @param target the target of the cascade sections
+   */
+  public void setTarget(DartExpression target) {
+    this.target = target;
+  }
+
+  @Override
+  public void visitChildren(ASTVisitor<?> visitor) {
+    safelyVisitChild(target, visitor);
+    cascadeSections.accept(visitor);
+  }
+}