UnaryNode.cs source code in C# .NET

                        Code:
                         / DotNET / DotNET / 8.0 / untmp / whidbey / REDBITS / ndp / fx / src / Data / System / Data / Filter / UnaryNode.cs / 1 / UnaryNode.cs
                        
                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// [....] 
// [....]
// [....] 
//----------------------------------------------------------------------------- 

namespace System.Data { 
    using System;
    using System.Collections.Generic;
    using System.Diagnostics;
    using System.Data.Common; 
    using System.Data.SqlTypes;
 
 
    internal sealed class UnaryNode : ExpressionNode {
        internal readonly int op; 

        internal ExpressionNode right;

        internal UnaryNode(DataTable table, int op, ExpressionNode right) : base(table) { 
            this.op = op;
            this.right = right; 
        } 

        internal override void Bind(DataTable table, List list) { 
            BindTable(table);
            right.Bind(table, list);
        }
 
        internal override object Eval() {
            return Eval(null, DataRowVersion.Default); 
        } 

        internal override object Eval(DataRow row, DataRowVersion version) { 
            return EvalUnaryOp(op, right.Eval(row, version));
        }

        internal override object Eval(int[] recordNos) { 
            return right.Eval(recordNos);
        } 
 
        private object EvalUnaryOp(int op, object vl) {
            object value = DBNull.Value; 

            if (DataExpression.IsUnknown(vl))
                return DBNull.Value;
 
            StorageType storageType;
            switch (op) { 
                case Operators.Noop: 
                    return vl;
                case Operators.UnaryPlus: 
                    storageType = DataStorage.GetStorageType(vl.GetType());
                    if (ExpressionNode.IsNumericSql(storageType)) {
                        return vl;
                    } 
                    throw ExprException.TypeMismatch(this.ToString());
 
                case Operators.Negative: 
                    // the have to be better way for doing this..
                    storageType = DataStorage.GetStorageType(vl.GetType()); 
                    if (ExpressionNode.IsNumericSql(storageType)) {
                        switch(storageType) {
                        case StorageType.Byte:
                            value = -(Byte) vl; 
                            break;
                        case StorageType.Int16: 
                            value = -(Int16) vl; 
                            break;
                        case StorageType.Int32: 
                            value = -(Int32) vl;
                            break;
                        case StorageType.Int64:
                            value = -(Int64) vl; 
                            break;
                        case StorageType.Single: 
                            value = -(Single) vl; 
                            break;
                        case StorageType.Double: 
                            value = -(Double) vl;
                            break;
                        case StorageType.Decimal:
                            value = -(Decimal) vl; 
                            break;
                        case StorageType.SqlDecimal: 
                            value = -(SqlDecimal) vl; 
                            break;
                        case StorageType.SqlDouble: 
                            value = -(SqlDouble) vl;
                            break;
                        case StorageType.SqlSingle:
                            value = -(SqlSingle) vl; 
                            break;
                        case StorageType.SqlMoney: 
                            value = -(SqlMoney) vl; 
                            break;
                        case StorageType.SqlInt64: 
                            value = -(SqlInt64) vl;
                            break;
                        case StorageType.SqlInt32:
                            value = -(SqlInt32) vl; 
                            break;
                        case StorageType.SqlInt16: 
                            value = -(SqlInt16) vl; 
                            break;
                        default: 
                            Debug.Assert(false, "Missing a type conversion");
                            value = DBNull.Value;
                            break;
                        } 
                        return value;
                    } 
 
                    throw ExprException.TypeMismatch(this.ToString());
 
                case Operators.Not:
                    if (vl is SqlBoolean){
                            if (((SqlBoolean)vl).IsFalse){
                                return SqlBoolean.True; 
                            }
                            else if (((SqlBoolean)vl).IsTrue) { 
                                      return SqlBoolean.False; 
                            }
                            throw ExprException.UnsupportedOperator(op);  // or should the result of not SQLNull  be SqlNull ? 
                    }
                    else{
                          if (DataExpression.ToBoolean(vl) != false)
                             return false; 
                          return true;
                    } 
 
                default:
                    throw ExprException.UnsupportedOperator(op); 
            }
        }

        internal override bool IsConstant() { 
            return(right.IsConstant());
        } 
 
        internal override bool IsTableConstant() {
            return(right.IsTableConstant()); 
        }

        internal override bool HasLocalAggregate() {
            return(right.HasLocalAggregate()); 
        }
 
        internal override bool HasRemoteAggregate() { 
            return(right.HasRemoteAggregate());
        } 

        internal override bool DependsOn(DataColumn column) {
            return(right.DependsOn(column));
        } 

 
        internal override ExpressionNode Optimize() { 
            right = right.Optimize();
 
            if (this.IsConstant()) {
                object val = this.Eval();

                return new ConstNode(table, ValueType.Object,  val, false); 
            }
            else 
                return this; 
        }
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
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UnaryNode.cs source code in C# .NET

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