ExpressionReferenceExplorer.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.Collections.Generic;

using Deveel.Data.Sql.Expressions;

namespace Deveel.Data.Sql.Query {
    static class ExpressionReferenceExplorer {
        public static IEnumerable<ObjectName> AllReferences(this SqlExpression expression) {
            var discover = new ReferenceDiscover();
            discover.Visit(expression);
            return discover.References.ToArray();
        }

        #region ReferenceDiscover

        class ReferenceDiscover : SqlExpressionVisitor {
            public ReferenceDiscover() {
                References = new List<ObjectName>();
            }

            public List<ObjectName> References { get; private set; }

            public override SqlExpression VisitReference(SqlReferenceExpression reference) {
                References.Add(reference.ReferenceName);
                return base.VisitReference(reference);
            }

            public override SqlExpression VisitConstant(SqlConstantExpression constant) {
                var value = constant.Value;
                // TODO: if this is an array ...

                return base.VisitConstant(constant);
            }
        }

        #endregion
    }
}