NameNode.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / Data / System / Data / Filter / NameNode.cs / 1305376 / NameNode.cs
                        
                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// [....] 
// [....]
// [....] 
//----------------------------------------------------------------------------- 

namespace System.Data { 
    using System;
    using System.ComponentModel;
    using System.Collections.Generic;
    using System.Diagnostics; 
    using System.Globalization;
 
    internal sealed class NameNode : ExpressionNode { 
        internal char open = '\0';
        internal char close = '\0'; 
        internal string name;
        internal bool found;
        internal bool type = false;
        internal DataColumn column; 

        internal NameNode(DataTable table, char[] text, int start, int pos) : base(table) { 
            this.name = ParseName(text, start, pos); 
        }
 
        internal NameNode(DataTable table, string name) : base(table) {
            this.name = name;
        }
 
        internal override bool IsSqlColumn{
            get{ 
                return column.IsSqlType; 
            }
        } 

        internal override void Bind(DataTable table, List list) {
            BindTable(table);
            if (table == null) 
                throw ExprException.UnboundName(name);
 
            try { 
                this.column = table.Columns[name];
            } 
            catch (Exception e) {
                found = false;
                //
                if (!Common.ADP.IsCatchableExceptionType(e)) { 
                    throw;
                } 
                throw ExprException.UnboundName(name); 
            }
 
            if (column == null)
                throw ExprException.UnboundName(name);

            name = column.ColumnName; 
            found = true;
 
            // add column to the dependency list, do not add duplicate columns 
            Debug.Assert(column != null, "Failed to bind column " + name);
 
            int i;
            for (i = 0; i < list.Count; i++) {
                // walk the list, check if the current column already on the list
                DataColumn dataColumn = list[i]; 
                if (column == dataColumn) {
                    break; 
                } 
            }
            if (i >= list.Count) { 
                list.Add(column);
            }
        }
 
        internal override object Eval() {
            // can not eval column without ROW value; 
            throw ExprException.EvalNoContext(); 
        }
 
        internal override object Eval(DataRow row, DataRowVersion version) {
            if (!found) {
                throw ExprException.UnboundName(name);
            } 

            if (row == null) { 
                if(IsTableConstant()) // this column is TableConstant Aggregate Function 
                    return column.DataExpression.Evaluate();
                else { 
                    throw ExprException.UnboundName(name);
                }
            }
 
            return column[row.GetRecordFromVersion(version)];
        } 
 
        internal override object Eval(int[] records) {
            throw ExprException.ComputeNotAggregate(this.ToString()); 
        }

        internal override bool IsConstant() {
            return false; 
        }
 
        internal override bool IsTableConstant() { 
            if (column != null && column.Computed) {
                return this.column.DataExpression.IsTableAggregate(); 
            }
            return false;
        }
 
        internal override bool HasLocalAggregate() {
            if (column != null && column.Computed) { 
                return this.column.DataExpression.HasLocalAggregate(); 
            }
            return false; 
        }

        internal override bool HasRemoteAggregate() {
            if (column != null && column.Computed) { 
                return this.column.DataExpression.HasRemoteAggregate();
            } 
            return false; 
        }
 
        internal override bool DependsOn(DataColumn column) {
            if (this.column == column)
                return true;
 
            if (this.column.Computed) {
                return this.column.DataExpression.DependsOn(column); 
            } 

            return false; 
        }

        internal override ExpressionNode Optimize() {
            return this; 
        }
 
        ///  
        ///     Parses given name and checks it validity
        ///  
        internal static string ParseName(char[] text, int start, int pos) {
            char esc = '\0';
            string charsToEscape = "";
            int saveStart = start; 
            int savePos = pos;
 
            if (text[start] == '`') { 
                Debug.Assert(text[checked((int)pos-1)] == '`', "Invalid identifyer bracketing, pos = " + pos.ToString(CultureInfo.InvariantCulture) + ", end = " + text[checked((int)pos-1)].ToString(CultureInfo.InvariantCulture));
                start = checked((int)start+1); 
                pos = checked((int)pos-1);
                esc = '\\';
                charsToEscape = "`";
            } 
            else if (text[start] == '[') {
                Debug.Assert(text[checked((int)pos-1)] == ']', "Invalid identifyer bracketing of name " + new string(text, start, pos-start) + " pos = " + pos.ToString(CultureInfo.InvariantCulture) + ", end = " + text[checked((int)pos-1)].ToString(CultureInfo.InvariantCulture)); 
                start = checked((int)start+1); 
                pos = checked((int)pos-1);
                esc = '\\'; 
                charsToEscape = "]\\";
            }

            if (esc != '\0') { 
                // scan the name in search for the ESC
                int posEcho = start; 
 
                for (int i = start; i < pos; i++) {
                    if (text[i] == esc) { 
                        if (i+1 < pos && charsToEscape.IndexOf(text[i+1]) >= 0) {
                            i++;
                        }
                    } 
                    text[posEcho] = text[i];
                    posEcho++; 
                } 
                pos = posEcho;
            } 

            if (pos == start)
                throw ExprException.InvalidName(new string(text, saveStart, savePos - saveStart));
 
            return new string(text, start, pos - start);
        } 
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
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NameNode.cs source code in C# .NET

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