content: /*
   * Copyright 1999-2012 Alibaba Group.
   *  
   * 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.
   */
  /**
   * (created at 2011-1-25)
   */
  package com.alibaba.cobar.parser.ast.fragment;
  
  import com.alibaba.cobar.parser.ast.ASTNode;
  import com.alibaba.cobar.parser.ast.expression.primary.ParamMarker;
  import com.alibaba.cobar.parser.visitor.SQLASTVisitor;
  
  /**
   * @author <a href="mailto:shuo.qius@alibaba-inc.com">QIU Shuo</a>
   */
  public class Limit implements ASTNode {
      /** when it is null, to sql generated must ignore this number */
      private final Number offset;
      private final Number size;
      private final ParamMarker offsetP;
      private final ParamMarker sizeP;
  
      public Limit(Number offset, Number size) {
          if (offset == null)
              throw new IllegalArgumentException();
          if (size == null)
              throw new IllegalArgumentException();
          this.offset = offset;
          this.size = size;
          this.offsetP = null;
          this.sizeP = null;
      }
  
      public Limit(Number offset, ParamMarker sizeP) {
          if (offset == null)
              throw new IllegalArgumentException();
          if (sizeP == null)
              throw new IllegalArgumentException();
          this.offset = offset;
          this.size = null;
          this.offsetP = null;
          this.sizeP = sizeP;
      }
  
      public Limit(ParamMarker offsetP, Number size) {
          if (offsetP == null)
              throw new IllegalArgumentException();
          if (size == null)
              throw new IllegalArgumentException();
          this.offset = null;
          this.size = size;
          this.offsetP = offsetP;
          this.sizeP = null;
      }
  
      public Limit(ParamMarker offsetP, ParamMarker sizeP) {
          if (offsetP == null)
              throw new IllegalArgumentException();
          if (sizeP == null)
              throw new IllegalArgumentException();
          this.offset = null;
          this.size = null;
          this.offsetP = offsetP;
          this.sizeP = sizeP;
      }
  
      /**
       * @return {@link ParamMarker} or {@link Number}
       */
      public Object getOffset() {
          return offset == null ? offsetP : offset;
      }
  
      /**
       * @return {@link ParamMarker} or {@link Number}
       */
      public Object getSize() {
          return size == null ? sizeP : size;
      }
  
      @Override
      public void accept(SQLASTVisitor visitor) {
          visitor.visit(this);
      }
  }
  