import org.apache.calcite.sql.SqlBinaryOperator; //导入依赖的package包/类
private void popOpStackAndBuildFilter() {
  // Parsing a special expression; handled holistically by the parent
  if (holisticExpression > 0) {
    return;
  }
  OpState currentOp = opStack.pop();
  int size = currentOp.getChildren().size();
  RexNode newFilter = null;
  if (size >= 1) {
    if (size == 1 && currentOp.getOp() instanceof SqlBinaryOperator) {
      /* The only operator for which we allow partial pushes is AND.
       * For all other operators we clear the children if one of the
       * children is a no push.
       */
      newFilter = currentOp.getChildren().get(0);
    } else {
      newFilter = builder.makeCall(currentOp.getOp(), currentOp.getChildren());
    }
  }

  if (newFilter != null) {
    // add this new filter to my parent boolean operator's children
    if (!opStack.isEmpty()) {
      OpState parentOp = opStack.peek();
      parentOp.addChild(newFilter);
    } else {
      resultCondition = newFilter;
    }
  }
}
 

import org.apache.calcite.sql.SqlBinaryOperator; //导入依赖的package包/类
private void popOpStackAndBuildFilter() {
  // Parsing a special expression; handled holistically by the parent
  if (holisticExpression > 0) {
    return;
  }
  OpState currentOp = opStack.pop();
  int size = currentOp.getChildren().size();
  RexNode newFilter = null;
  if (size >= 1) {
    if (size == 1 && currentOp.getOp() instanceof SqlBinaryOperator) {
      /* The only operator for which we allow partial pushes is AND.
       * For all other operators we clear the children if one of the
       * children is a no push.
       */
      if (currentOp.getOp().getKind() == SqlKind.AND) {
        newFilter = currentOp.getChildren().get(0);
        for (OpState opState : opStack) {
          if (opState.getOp().getKind() == SqlKind.NOT) {
            //AND under NOT should not get pushed
            newFilter = null;
          }
        }

      }
    } else {
      newFilter = builder.makeCall(currentOp.getOp(), currentOp.getChildren());
    }
  }

  if (newFilter != null) {
    // add this new filter to my parent boolean operator's children
    if (!opStack.isEmpty()) {
      OpState parentOp = opStack.peek();
      parentOp.addChild(newFilter);
    } else {
      resultCondition = newFilter;
    }
  }
}
 

import org.apache.calcite.sql.SqlBinaryOperator; //导入依赖的package包/类
public static Operator getOperator(SqlBinaryOperator sqlBinaryOperator) {
    Operator operator = operatorTable.get(sqlBinaryOperator);
    if (operator == null) {
        throw new UnsupportedOperationException("Operator " + sqlBinaryOperator.getName() + " is not supported");
    }
    return operator;
}
 

import org.apache.calcite.sql.SqlBinaryOperator; //导入依赖的package包/类
private static ImmutableMap<SqlBinaryOperator, Operator> buildTable() {
    return ImmutableMap.<SqlBinaryOperator, Operator>builder()
    .put(SqlStdOperatorTable.GREATER_THAN, Operator.GREATER_THAN)
    .put(SqlStdOperatorTable.LESS_THAN, Operator.LESS_THAN)
    .put(SqlStdOperatorTable.GREATER_THAN_OR_EQUAL, Operator.GREATER_THAN_EQUALS_TO)
    .put(SqlStdOperatorTable.LESS_THAN_OR_EQUAL, Operator.LESS_THAN_EQUALS_TO)
    .put(SqlStdOperatorTable.EQUALS, Operator.EQUALS)
    .put(SqlStdOperatorTable.NOT_EQUALS, Operator.NOT_EQUAL)
    .put(SqlStdOperatorTable.AND, Operator.AND)
    .put(SqlStdOperatorTable.OR, Operator.OR)
    .build();
}
 

import org.apache.calcite.sql.SqlBinaryOperator; //导入依赖的package包/类
@Override
public Expression visit(SqlCall call) {
    SqlOperator sqlOperator = call.getOperator();
    if (sqlOperator instanceof SqlBinaryOperator) {
        return visitBinaryOperator((SqlBinaryOperator) sqlOperator, call.getOperandList().get(0),
                call.getOperandList().get(1));
    } else if (sqlOperator instanceof SqlSpecialOperator) {
        return visitSqlSpecialOperator((SqlSpecialOperator) sqlOperator, call.getOperandList());
    } else if (sqlOperator instanceof SqlFunction) {
        SqlFunction sqlFunction = (SqlFunction) sqlOperator;
        if (sqlFunction instanceof SqlAggFunction) {
            return visitAggregateFunction(sqlFunction.getName(), call.getOperandList());
        } else if (sqlFunction instanceof SqlUnresolvedFunction) {
            String udfName = sqlFunction.getName().toUpperCase();
            if (catalogUdfs.containsKey(udfName)) {
                Udf udfInfo = catalogUdfs.get(udfName);
                if (udfInfo.isAggregate()) {
                    return visitUserDefinedAggregateFunction(udfInfo, call.getOperandList());
                } else {
                    return visitUserDefinedFunction(udfInfo, call.getOperandList());
                }
            } else {
                throw new UnsupportedOperationException("Unknown built-in or User defined function '" + udfName + "'");
            }
        } else {
            return visitFunction(sqlFunction.getName(), call.getOperandList());
        }
    } else {
        throw new UnsupportedOperationException("Operator " + sqlOperator.getName() + " is not supported");
    }
}
 

import org.apache.calcite.sql.SqlBinaryOperator; //导入依赖的package包/类
private boolean getFilter(SqlOperator op, List<RexNode> operands,
    StringBuilder s, List<String> fieldNames) {
  if (!valid(op.getKind())) {
    return false;
  }

  boolean like = false;
  switch (op.getKind()) {
  case NOT:
    // NOT op pre-pended
    s = s.append(" NOT ");
    break;
  case CAST:
    return asd(false, operands, s, fieldNames, 0);
  case LIKE:
    like = true;
    break;
  }

  for (int i = 0; i < operands.size(); i++) {
    if (!asd(like, operands, s, fieldNames, i)) {
      return false;
    }
    if (op instanceof SqlBinaryOperator && i == 0) {
      s.append(" ").append(op).append(" ");
    }
  }
  return true;
}
 

import org.apache.calcite.sql.SqlBinaryOperator; //导入依赖的package包/类
private Expression visitBinaryOperator(SqlBinaryOperator binaryOperator, SqlNode left, SqlNode right) {
    Operator operator = BinaryOperatorTable.getOperator(binaryOperator);
    return new BinaryExpression(operator, left.accept(this), right.accept(this));
}
 

import org.apache.calcite.sql.SqlBinaryOperator; //导入依赖的package包/类
private RexNode binary(Expression expression, SqlBinaryOperator op) {
  BinaryExpression call = (BinaryExpression) expression;
  return rexBuilder.makeCall(type(call), op,
      toRex(ImmutableList.of(call.expression0, call.expression1)));
}
 

import org.apache.calcite.sql.SqlBinaryOperator; //导入依赖的package包/类
public Expression implement(
    RexToLixTranslator translator,
    RexCall call,
    List<Expression> expressions) {
  // neither nullable:
  //   return x OP y
  // x nullable
  //   null_returns_null
  //     return x == null ? null : x OP y
  //   ignore_null
  //     return x == null ? null : y
  // x, y both nullable
  //   null_returns_null
  //     return x == null || y == null ? null : x OP y
  //   ignore_null
  //     return x == null ? y : y == null ? x : x OP y
  if (backupMethodName != null) {
    // If one or both operands have ANY type, use the late-binding backup
    // method.
    if (anyAnyOperands(call)) {
      return callBackupMethodAnyType(translator, call, expressions);
    }

    final Type type0 = expressions.get(0).getType();
    final Type type1 = expressions.get(1).getType();
    final SqlBinaryOperator op = (SqlBinaryOperator) call.getOperator();
    final Primitive primitive = Primitive.ofBoxOr(type0);
    if (primitive == null
        || type1 == BigDecimal.class
        || COMPARISON_OPERATORS.contains(op)
        && !COMP_OP_TYPES.contains(primitive)) {
      return Expressions.call(SqlFunctions.class, backupMethodName,
          expressions);
    }
  }

  final Type returnType =
      translator.typeFactory.getJavaClass(call.getType());
  return Types.castIfNecessary(returnType,
      Expressions.makeBinary(expressionType, expressions.get(0),
          expressions.get(1)));
}