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.sql;
  
  import org.apache.calcite.linq4j.Ord;
  import org.apache.calcite.sql.type.SqlOperandTypeChecker;
  import org.apache.calcite.sql.type.SqlOperandTypeInference;
  import org.apache.calcite.sql.type.SqlReturnTypeInference;
  
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  /**
   * A generalization of a binary operator to involve several (two or more)
   * arguments, and keywords between each pair of arguments.
   *
   * <p>For example, the <code>BETWEEN</code> operator is ternary, and has syntax
   * <code><i>exp1</i> BETWEEN <i>exp2</i> AND <i>exp3</i></code>.
   */
  public class SqlInfixOperator extends SqlSpecialOperator {
    //~ Instance fields --------------------------------------------------------
  
    private final String[] names;
  
    //~ Constructors -----------------------------------------------------------
  
    protected SqlInfixOperator(
        String[] names,
        SqlKind kind,
        int precedence,
        @Nullable SqlReturnTypeInference returnTypeInference,
        @Nullable SqlOperandTypeInference operandTypeInference,
        @Nullable SqlOperandTypeChecker operandTypeChecker) {
      super(
          names[0],
          kind,
          precedence,
          true,
          returnTypeInference,
          operandTypeInference,
          operandTypeChecker);
      assert names.length > 1;
      this.names = names;
    }
  
    //~ Methods ----------------------------------------------------------------
  
    @Override public void unparse(
        SqlWriter writer,
        SqlCall call,
        int leftPrec,
        int rightPrec) {
      assert call.operandCount() == names.length + 1;
      final boolean needWhitespace = needsSpace();
      for (Ord<SqlNode> operand : Ord.zip(call.getOperandList())) {
        if (operand.i > 0) {
          writer.setNeedWhitespace(needWhitespace);
          writer.keyword(names[operand.i - 1]);
          writer.setNeedWhitespace(needWhitespace);
        }
        operand.e.unparse(writer, leftPrec, getLeftPrec());
      }
    }
  }
  