IdentifierService.cs source code in C# .NET

                        Code:
                         / Dotnetfx_Win7_3.5.1 / Dotnetfx_Win7_3.5.1 / 3.5.1 / DEVDIV / depot / DevDiv / releases / Orcas / NetFXw7 / ndp / fx / src / DataEntity / System / Data / Common / Utils / Boolean / IdentifierService.cs / 1 / IdentifierService.cs
                        
                        
                            //---------------------------------------------------------------------- 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// 
// @owner [....]
// @backupOwner [....] 
//--------------------------------------------------------------------- 

using System; 
using System.Collections.Generic;
using System.Text;
using System.Diagnostics;
using System.Collections.ObjectModel; 
using System.Globalization;
using System.Linq; 
 
namespace System.Data.Common.Utils.Boolean
{ 
    /// 
    /// Services related to different identifier types for Boolean expressions.
    /// 
    internal abstract class IdentifierService 
    {
        #region Static members 
        internal static readonly IdentifierService Instance = GetIdentifierService(); 
        private static IdentifierService GetIdentifierService()
        { 
            Type identifierType = typeof(T_Identifier);
            if (identifierType.IsGenericType &&
                identifierType.GetGenericTypeDefinition() == typeof(DomainConstraint<,>))
            { 
                // initialize a domain constraint literal service
                Type[] genericArguments = identifierType.GetGenericArguments(); 
                Type variableType = genericArguments[0]; 
                Type elementType = genericArguments[1];
                return (IdentifierService)Activator.CreateInstance( 
                    typeof(DomainConstraintIdentifierService<,>).MakeGenericType(identifierType, variableType, elementType));
            }
            else
            { 
                // initialize a generic literal service for all other identifier types
                return new GenericIdentifierService(); 
            } 
        }
        #endregion 

        #region Constructors
        private IdentifierService()
        { 
        }
        #endregion 
 
        #region Service methods
        ///  
        /// Returns negation of the given literal.
        /// 
        internal abstract Literal NegateLiteral(Literal literal);
 
        /// 
        /// Creates a new conversion context. 
        ///  
        internal abstract ConversionContext CreateConversionContext();
 
        /// 
        /// Performs local simplification appropriate to the current identifier.
        /// 
        internal abstract BoolExpr LocalSimplify(BoolExpr expression); 
        #endregion
 
        private class GenericIdentifierService : IdentifierService 
        {
            internal override Literal NegateLiteral(Literal literal) 
            {
                // just invert the sign
                return new Literal(literal.Term, !literal.IsTermPositive);
            } 

            internal override ConversionContext CreateConversionContext() 
            { 
                return new GenericConversionContext();
            } 

            internal override BoolExpr LocalSimplify(BoolExpr expression)
            {
                return expression.Accept(Simplifier.Instance); 
            }
        } 
 
        private class DomainConstraintIdentifierService : IdentifierService>
        { 
            internal override Literal> NegateLiteral(Literal> literal)
            {
                // negate the literal by inverting the range, rather than changing the sign
                // of the literal 
                TermExpr> term = new TermExpr>(
                    literal.Term.Identifier.InvertDomainConstraint()); 
                return new Literal>(term, literal.IsTermPositive); 
            }
 
            internal override ConversionContext> CreateConversionContext()
            {
                return new DomainConstraintConversionContext();
            } 

            internal override BoolExpr> LocalSimplify(BoolExpr> expression) 
            { 
                expression = NegationPusher.EliminateNot(expression);
                return expression.Accept(Simplifier>.Instance); 
            }
        }
    }
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
//---------------------------------------------------------------------- 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// 
// @owner [....]
// @backupOwner [....] 
//--------------------------------------------------------------------- 

using System; 
using System.Collections.Generic;
using System.Text;
using System.Diagnostics;
using System.Collections.ObjectModel; 
using System.Globalization;
using System.Linq; 
 
namespace System.Data.Common.Utils.Boolean
{ 
    /// 
    /// Services related to different identifier types for Boolean expressions.
    /// 
    internal abstract class IdentifierService 
    {
        #region Static members 
        internal static readonly IdentifierService Instance = GetIdentifierService(); 
        private static IdentifierService GetIdentifierService()
        { 
            Type identifierType = typeof(T_Identifier);
            if (identifierType.IsGenericType &&
                identifierType.GetGenericTypeDefinition() == typeof(DomainConstraint<,>))
            { 
                // initialize a domain constraint literal service
                Type[] genericArguments = identifierType.GetGenericArguments(); 
                Type variableType = genericArguments[0]; 
                Type elementType = genericArguments[1];
                return (IdentifierService)Activator.CreateInstance( 
                    typeof(DomainConstraintIdentifierService<,>).MakeGenericType(identifierType, variableType, elementType));
            }
            else
            { 
                // initialize a generic literal service for all other identifier types
                return new GenericIdentifierService(); 
            } 
        }
        #endregion 

        #region Constructors
        private IdentifierService()
        { 
        }
        #endregion 
 
        #region Service methods
        ///  
        /// Returns negation of the given literal.
        /// 
        internal abstract Literal NegateLiteral(Literal literal);
 
        /// 
        /// Creates a new conversion context. 
        ///  
        internal abstract ConversionContext CreateConversionContext();
 
        /// 
        /// Performs local simplification appropriate to the current identifier.
        /// 
        internal abstract BoolExpr LocalSimplify(BoolExpr expression); 
        #endregion
 
        private class GenericIdentifierService : IdentifierService 
        {
            internal override Literal NegateLiteral(Literal literal) 
            {
                // just invert the sign
                return new Literal(literal.Term, !literal.IsTermPositive);
            } 

            internal override ConversionContext CreateConversionContext() 
            { 
                return new GenericConversionContext();
            } 

            internal override BoolExpr LocalSimplify(BoolExpr expression)
            {
                return expression.Accept(Simplifier.Instance); 
            }
        } 
 
        private class DomainConstraintIdentifierService : IdentifierService>
        { 
            internal override Literal> NegateLiteral(Literal> literal)
            {
                // negate the literal by inverting the range, rather than changing the sign
                // of the literal 
                TermExpr> term = new TermExpr>(
                    literal.Term.Identifier.InvertDomainConstraint()); 
                return new Literal>(term, literal.IsTermPositive); 
            }
 
            internal override ConversionContext> CreateConversionContext()
            {
                return new DomainConstraintConversionContext();
            } 

            internal override BoolExpr> LocalSimplify(BoolExpr> expression) 
            { 
                expression = NegationPusher.EliminateNot(expression);
                return expression.Accept(Simplifier>.Instance); 
            }
        }
    }
} 

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

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