/* * Copyright 2012, the Dart project authors. * * Licensed under the Eclipse Public License v1.0 (the "License"); you may not use this file except * in compliance with the License. You may obtain a copy of the License at * * http://www.eclipse.org/legal/epl-v10.html * * Unless required by applicable law or agreed to in writing, software distributed under the License * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express * or implied. See the License for the specific language governing permissions and limitations under * the License. */ package com.google.dart.engine.ast; /** * Instances of the class {@code StringLiteral} represent a string literal expression. * * <pre> * stringLiteral ::= * {@link SimpleStringLiteral simpleStringLiteral} * | {@link AdjacentStrings adjacentStrings} * | {@link StringInterpolation stringInterpolation} * </pre> * * @coverage dart.engine.ast */ public abstract class StringLiteral extends Literal { /** * Return the value of the string literal, or {@code null} if the string is not a constant string * without any string interpolation. * * @return the value of the string literal */ public String getStringValue() { StringBuilder builder = new StringBuilder(); try { appendStringValue(builder); } catch (IllegalArgumentException exception) { return null; } return builder.toString(); } /** * Append the value of the given string literal to the given string builder. * * @param builder the builder to which the string's value is to be appended * @throws IllegalArgumentException if the string is not a constant string without any string * interpolation */ protected abstract void appendStringValue(StringBuilder builder) throws IllegalArgumentException; }