| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0 |
| * |
| * 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 freemarker.core; |
| |
| |
| import freemarker.template.SimpleCollection; |
| import freemarker.template.TemplateCollectionModel; |
| import freemarker.template.TemplateException; |
| import freemarker.template.TemplateHashModelEx; |
| import freemarker.template.TemplateModel; |
| import freemarker.template.TemplateScalarModel; |
| import freemarker.template.TemplateSequenceModel; |
| |
| /** {@code exp!defExp}, {@code (exp)!defExp} and the same two with {@code (exp)!}. */ |
| class DefaultToExpression extends Expression { |
| |
| private static final TemplateCollectionModel EMPTY_COLLECTION = new SimpleCollection(new java.util.ArrayList(0)); |
| |
| static private class EmptyStringAndSequence |
| implements TemplateScalarModel, TemplateSequenceModel, TemplateHashModelEx { |
| public String getAsString() { |
| return ""; |
| } |
| public TemplateModel get(int i) { |
| return null; |
| } |
| public TemplateModel get(String s) { |
| return null; |
| } |
| public int size() { |
| return 0; |
| } |
| public boolean isEmpty() { |
| return true; |
| } |
| public TemplateCollectionModel keys() { |
| return EMPTY_COLLECTION; |
| } |
| public TemplateCollectionModel values() { |
| return EMPTY_COLLECTION; |
| } |
| |
| } |
| |
| static final TemplateModel EMPTY_STRING_AND_SEQUENCE = new EmptyStringAndSequence(); |
| |
| private final Expression lho, rho; |
| |
| DefaultToExpression(Expression lho, Expression rho) { |
| this.lho = lho; |
| this.rho = rho; |
| } |
| |
| @Override |
| TemplateModel _eval(Environment env) throws TemplateException { |
| TemplateModel left; |
| if (lho instanceof ParentheticalExpression) { |
| boolean lastFIRE = env.setFastInvalidReferenceExceptions(true); |
| try { |
| left = lho.eval(env); |
| } catch (InvalidReferenceException ire) { |
| left = null; |
| } finally { |
| env.setFastInvalidReferenceExceptions(lastFIRE); |
| } |
| } else { |
| left = lho.eval(env); |
| } |
| |
| if (left != null) return left; |
| else if (rho == null) return EMPTY_STRING_AND_SEQUENCE; |
| else return rho.eval(env); |
| } |
| |
| @Override |
| boolean isLiteral() { |
| return false; |
| } |
| |
| @Override |
| protected Expression deepCloneWithIdentifierReplaced_inner(String replacedIdentifier, Expression replacement, ReplacemenetState replacementState) { |
| return new DefaultToExpression( |
| lho.deepCloneWithIdentifierReplaced(replacedIdentifier, replacement, replacementState), |
| rho != null |
| ? rho.deepCloneWithIdentifierReplaced(replacedIdentifier, replacement, replacementState) |
| : null); |
| } |
| |
| @Override |
| public String getCanonicalForm() { |
| if (rho == null) { |
| return lho.getCanonicalForm() + '!'; |
| } |
| return lho.getCanonicalForm() + '!' + rho.getCanonicalForm(); |
| } |
| |
| @Override |
| String getNodeTypeSymbol() { |
| return "...!..."; |
| } |
| |
| @Override |
| int getParameterCount() { |
| return 2; |
| } |
| |
| @Override |
| Object getParameterValue(int idx) { |
| switch (idx) { |
| case 0: return lho; |
| case 1: return rho; |
| default: throw new IndexOutOfBoundsException(); |
| } |
| } |
| |
| @Override |
| ParameterRole getParameterRole(int idx) { |
| return ParameterRole.forBinaryOperatorOperand(idx); |
| } |
| |
| } |