content: /*
   * 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 org.apache.calcite.linq4j.tree;
  
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  import java.lang.reflect.Type;
  import java.util.Objects;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * Represents an expression that has a unary operator.
   */
  public class UnaryExpression extends Expression {
    public final Expression expression;
  
    UnaryExpression(ExpressionType nodeType, Type type, Expression expression) {
      super(nodeType, type);
      this.expression = requireNonNull(expression, "expression");
    }
  
    @Override public Expression accept(Shuttle shuttle) {
      shuttle = shuttle.preVisit(this);
      Expression expression = this.expression.accept(shuttle);
      return shuttle.visit(this, expression);
    }
  
    @Override public <R> R accept(Visitor<R> visitor) {
      return visitor.visit(this);
    }
  
    @Override void accept(ExpressionWriter writer, int lprec, int rprec) {
      switch (nodeType) {
      case Convert:
        if (!writer.requireParentheses(this, lprec, rprec)) {
          writer.append("(").append(type).append(") ");
          expression.accept(writer, nodeType.rprec, rprec);
        }
        return;
      case ConvertChecked:
        // This is ugly, but Java does not seem to have any facilities
        // to perform checked cast between scalar types!
        // So we use the existing linq4j Primitive.numberValue method
        // which does overflow checking.
        if (!writer.requireParentheses(this, lprec, rprec)) {
          // Generate Java code that looks like e.g.,
          // ((Number)org.apache.calcite.linq4j.tree.Primitive.of(int.class)
          //     .numberValueRoundDown(literal_value)).intValue();
          writer.append("((Number)")
              .append("org.apache.calcite.linq4j.tree.Primitive.of(")
              .append(type)
              .append(".class)")
              .append(".numberValueRoundDown(");
          expression.accept(writer, nodeType.rprec, rprec);
          writer.append(")).").append(type).append("Value()");
        }
        return;
      default:
        break;
      }
      if (nodeType.postfix) {
        expression.accept(writer, lprec, nodeType.rprec);
        writer.append(nodeType.op);
      } else {
        writer.append("(");
        writer.append(nodeType.op);
        expression.accept(writer, nodeType.lprec, rprec);
        writer.append(")");
      }
    }
  
    @Override public boolean equals(@Nullable Object o) {
      if (this == o) {
        return true;
      }
      if (o == null || getClass() != o.getClass()) {
        return false;
      }
      if (!super.equals(o)) {
        return false;
      }
  
      UnaryExpression that = (UnaryExpression) o;
      return expression.equals(that.expression);
    }
  
    @Override public int hashCode() {
      return Objects.hash(nodeType, type, expression);
    }
  }
  