SqlBinaryExpressionNode.cs

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// 
//  Copyright 2010-2015 Deveel
// 
//    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.
//

using System;
using System.Linq;
using System.Text;

namespace Deveel.Data.Sql.Parser {
    class SqlBinaryExpressionNode : SqlNode, IExpressionNode {
        private bool leftSeen;

        public IExpressionNode Left { get; private set; }

        public IExpressionNode Right { get; private set; }

        public bool IsAll { get; private set; }

        public bool IsAny { get; private set; }

        public string Operator { get; private set; }

        protected override ISqlNode OnChildNode(ISqlNode node) {
            if (node is IExpressionNode) {
                if (!leftSeen) {
                    Left = (IExpressionNode) node;
                    leftSeen = true;
                } else {
                    Right = (IExpressionNode) node;
                    leftSeen = false;
                }
            } else if (node.NodeName == "binary_op") {
                GetOperator(node);
            }

            return base.OnChildNode(node);
        }

        private void GetOperator(ISqlNode node) {
            var childNode = node.ChildNodes.First();
            if (childNode.NodeName == "binary_op_simple") {
                var op = childNode.ChildNodes.First();
                Operator = ((SqlKeyNode) op).Text;
            } else if (childNode.NodeName == "logical_op") {
                GetLogicalOp(childNode); 
            } else if (node.NodeName == "any_op" ||
                       node.NodeName == "all_op") {
                GetAnyAllOp(childNode);
            } else if (childNode.NodeName == "subquery_op") {
                GetLogicalOp(childNode);
            }
        }

        private void GetLogicalOp(ISqlNode node) {
            var sb = new StringBuilder();
            foreach (var childNode in node.ChildNodes) {
                if (childNode is SqlKeyNode) {
                    sb.Append(((SqlKeyNode) childNode).Text);
                    sb.Append(" ");
                }
            }

            Operator = sb.ToString().Trim();
        }

        private void GetAnyAllOp(ISqlNode node) {
            var sb = new StringBuilder();
            foreach (var childNode in node.ChildNodes) {
                if (childNode is SqlKeyNode) {
                    var anyOrAll = ((SqlKeyNode) childNode).Text;
                    if (String.Equals(anyOrAll, "ALL", StringComparison.OrdinalIgnoreCase)) {
                        IsAll = true;
                    } else if (String.Equals(anyOrAll, "ANY", StringComparison.OrdinalIgnoreCase)) {
                        IsAny = true;
                    }
                } else if (childNode.NodeName == "binary_op_simple") {
                    var op = childNode.ChildNodes.First();
                    sb.Append(((SqlKeyNode) op).Text);
                }
            }

            Operator = sb.ToString();
        }
    }
}