/*
// Licensed to Julian Hyde under one or more contributor license
// agreements. See the NOTICE file distributed with this work for
// additional information regarding copyright ownership.
//
// Julian Hyde 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 net.hydromatic.linq4j.expressions;

import java.lang.reflect.Modifier;
import java.lang.reflect.Type;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * Represents a named parameter expression.
 */
public class ParameterExpression extends Expression {
  private static final AtomicInteger SEQ = new AtomicInteger();

  public final int modifier;
  public final String name;

  public ParameterExpression(Type type) {
    this(0, type, "p" + SEQ.getAndIncrement());
  }

  public ParameterExpression(int modifier, Type type, String name) {
    super(ExpressionType.Parameter, type);
    this.modifier = modifier;
    this.name = name;
  }

  @Override
  public Expression accept(Visitor visitor) {
    return visitor.visit(this);
  }

  public Object evaluate(Evaluator evaluator) {
    return evaluator.peek(this);
  }

  @Override
  void accept(ExpressionWriter writer, int lprec, int rprec) {
    writer.append(name);
  }

  String declString() {
    return declString(type);
  }

  String declString(Type type) {
    final String modifiers = Modifier.toString(modifier);
    return modifiers
        + (modifiers.isEmpty() ? "" : " ")
        + Types.className(type)
        + " "
        + name;
  }
}

// End ParameterExpression.java