content: /*
   * Copyright 2010-2025 Hyland Software, Inc. and its affiliates.
   *
   * Licensed 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 org.activiti.core.el.juel.tree.impl.ast;
  
  import jakarta.el.ELContext;
  import jakarta.el.ELException;
  import org.activiti.core.el.juel.misc.BooleanOperations;
  import org.activiti.core.el.juel.misc.NumberOperations;
  import org.activiti.core.el.juel.misc.TypeConverter;
  import org.activiti.core.el.juel.tree.Bindings;
  
  public class AstUnary extends AstRightValue {
  
      public interface Operator {
          public Object eval(Bindings bindings, ELContext context, AstNode node);
      }
  
      public abstract static class SimpleOperator implements Operator {
  
          public Object eval(Bindings bindings, ELContext context, AstNode node) {
              return apply(bindings, node.eval(bindings, context));
          }
  
          protected abstract Object apply(TypeConverter converter, Object o);
      }
  
      public static final Operator EMPTY = new SimpleOperator() {
          @Override
          public Object apply(TypeConverter converter, Object o) {
              return BooleanOperations.empty(converter, o);
          }
  
          @Override
          public String toString() {
              return "empty";
          }
      };
      public static final Operator NEG = new SimpleOperator() {
          @Override
          public Object apply(TypeConverter converter, Object o) {
              return NumberOperations.neg(converter, o);
          }
  
          @Override
          public String toString() {
              return "-";
          }
      };
      public static final Operator NOT = new SimpleOperator() {
          @Override
          public Object apply(TypeConverter converter, Object o) {
              return !converter.convert(o, Boolean.class);
          }
  
          @Override
          public String toString() {
              return "!";
          }
      };
  
      private final Operator operator;
      private final AstNode child;
  
      public AstUnary(AstNode child, Operator operator) {
          this.child = child;
          this.operator = operator;
      }
  
      public Operator getOperator() {
          return operator;
      }
  
      @Override
      public Object eval(Bindings bindings, ELContext context) throws ELException {
          return operator.eval(bindings, context, child);
      }
  
      @Override
      public String toString() {
          return "'" + operator.toString() + "'";
      }
  
      @Override
      public void appendStructure(StringBuilder b, Bindings bindings) {
          b.append(operator);
          b.append(' ');
          child.appendStructure(b, bindings);
      }
  
      public int getCardinality() {
          return 1;
      }
  
      public AstNode getChild(int i) {
          return i == 0 ? child : null;
      }
  }
  