org.jetbrains.kotlin.js.backend.JsConstructExpressionVisitor Maven / Gradle / Ivy
// 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.
package org.jetbrains.kotlin.js.backend;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.kotlin.js.backend.ast.*;
/**
* Searches for method invocations in constructor expressions that would not
* normally be surrounded by parentheses.
*/
public class JsConstructExpressionVisitor extends RecursiveJsVisitor {
public static boolean exec(JsExpression expression) {
if (JsPrecedenceVisitor.exec(expression) < JsPrecedenceVisitor.PRECEDENCE_NEW) {
return true;
}
JsConstructExpressionVisitor visitor = new JsConstructExpressionVisitor();
visitor.accept(expression);
return visitor.containsInvocation;
}
private boolean containsInvocation;
private JsConstructExpressionVisitor() {
}
/**
* We only look at the array expression since the index has its own scope.
*/
@Override
public void visitArrayAccess(@NotNull JsArrayAccess x) {
accept(x.getArrayExpression());
}
/**
* Array literals have their own scoping.
*/
@Override
public void visitArray(@NotNull JsArrayLiteral x) {
}
/**
* Functions have their own scoping.
*/
@Override
public void visitFunction(@NotNull JsFunction x) {
}
@Override
public void visitInvocation(@NotNull JsInvocation invocation) {
containsInvocation = true;
}
@Override
public void visitNameRef(@NotNull JsNameRef nameRef) {
if (!nameRef.isLeaf()) {
accept(nameRef.getQualifier());
}
}
/**
* New constructs bind to the nearest set of parentheses.
*/
@Override
public void visitNew(@NotNull JsNew x) {
}
/**
* Object literals have their own scope.
*/
@Override
public void visitObjectLiteral(@NotNull JsObjectLiteral x) {
}
/**
* We only look at nodes that would not normally be surrounded by parentheses.
*/
@Override
public void accept(T node) {
// Assign to Object to prevent 'inconvertible types' compile errors due
// to http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6548436
// reproducible in jdk1.6.0_02.
if (node instanceof JsExpression) {
JsExpression expression = (JsExpression) node;
int precedence = JsPrecedenceVisitor.exec(expression);
// Only visit expressions that won't automatically be surrounded by
// parentheses
if (precedence < JsPrecedenceVisitor.PRECEDENCE_NEW) {
return;
}
}
super.accept(node);
}
}