Literal.cs source code in C# .NET

Source code for the .NET framework in C#

                        

Code:

/ 4.0 / 4.0 / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / DataEntity / System / Data / Common / EntitySql / AST / Literal.cs / 1305376 / Literal.cs

                            //---------------------------------------------------------------------- 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// 
// @owner  [....]
// @backupOwner [....] 
//--------------------------------------------------------------------- 

namespace System.Data.Common.EntitySql.AST 
{
    using System;
    using System.Globalization;
    using System.Collections; 
    using System.Collections.Generic;
    using System.Diagnostics; 
    using System.Text; 

    ///  
    /// Defines literal value kind, including the eSQL untyped NULL.
    /// 
    internal enum LiteralKind
    { 
        Number,
        String, 
        UnicodeString, 
        Boolean,
        Binary, 
        DateTime,
        Time,
        DateTimeOffset,
        Guid, 
        Null
    } 
 
    /// 
    /// Represents a literal ast node. 
    /// 
    internal sealed class Literal : Node
    {
        private readonly LiteralKind _literalKind; 
        private string _originalValue;
        private bool _wasValueComputed = false; 
        private object _computedValue; 
        private Type _type;
        private static readonly Byte[] _emptyByteArray = new byte[0]; 

        /// 
        /// Initializes a literal ast node.
        ///  
        /// literal value in cql string representation
        /// literal value class 
        /// query 
        /// input position
        internal Literal(string originalValue, LiteralKind kind, string query, int inputPos) 
            : base(query, inputPos)
        {
            _originalValue = originalValue;
            _literalKind = kind; 
        }
 
        ///  
        /// Static factory to create boolean literals by value only.
        ///  
        /// 
        internal static Literal NewBooleanLiteral(bool value) { return new Literal(value); }

        private Literal(bool boolLiteral) 
            : base(null, 0)
        { 
            _wasValueComputed = true; 
            _originalValue = String.Empty;
            _computedValue = boolLiteral; 
            _type = typeof(System.Boolean);
        }

        ///  
        /// True if literal is a number.
        ///  
        internal bool IsNumber 
        {
            get 
            {
                return (_literalKind == LiteralKind.Number);
            }
        } 

        ///  
        /// True if literal is a signed number. 
        /// 
        internal bool IsSignedNumber 
        {
            get
            {
                return IsNumber && (_originalValue[0] == '-' || _originalValue[0] == '+'); 
            }
        } 
 
        /// 
        /// True if literal is a string. 
        /// 
        /// 
        /// 
        ///  
        internal bool IsString
        { 
            get 
            {
                return _literalKind == LiteralKind.String || _literalKind == LiteralKind.UnicodeString; 
            }
        }

        ///  
        /// True if literal is a unicode string.
        ///  
        ///  
        /// 
        ///  
        internal bool IsUnicodeString
        {
            get
            { 
                return _literalKind == LiteralKind.UnicodeString;
            } 
        } 

        ///  
        /// True if literal is the eSQL untyped null.
        /// 
        /// 
        ///  
        /// 
        internal bool IsNullLiteral 
        { 
            get
            { 
                return _literalKind == LiteralKind.Null;
            }
        }
 
        /// 
        /// Returns the original literal value. 
        ///  
        internal string OriginalValue
        { 
            get
            {
                return _originalValue;
            } 
        }
 
        ///  
        /// Prefix a numeric literal with a sign.
        ///  
        internal void PrefixSign(string sign)
        {
            System.Diagnostics.Debug.Assert(IsNumber && !IsSignedNumber);
            System.Diagnostics.Debug.Assert(sign[0] == '-' || sign[0] == '+', "sign symbol must be + or -"); 
            System.Diagnostics.Debug.Assert(_computedValue == null);
 
            _originalValue = sign + _originalValue; 
        }
 
        #region Computed members
        /// 
        /// Returns literal converted value.
        ///  
        /// 
        ///  
        ///  
        internal object Value
        { 
            get
            {
                ComputeValue();
 
                return _computedValue;
            } 
        } 

        ///  
        /// Returns literal value type. If value is eSQL untyped null, returns null.
        /// 
        /// 
        ///  
        /// 
        internal Type Type 
        { 
            get
            { 
                ComputeValue();

                return _type;
            } 
        }
        #endregion 
 
        private void ComputeValue()
        { 
            if (!_wasValueComputed)
            {
                _wasValueComputed = true;
 
                switch (_literalKind)
                { 
                    case LiteralKind.Number: 
                        _computedValue = ConvertNumericLiteral(ErrCtx, _originalValue);
                        break; 

                    case LiteralKind.String:
                        _computedValue = GetStringLiteralValue(_originalValue, false /* isUnicode */);
                        break; 

                    case LiteralKind.UnicodeString: 
                        _computedValue = GetStringLiteralValue(_originalValue, true /* isUnicode */); 
                        break;
 
                    case LiteralKind.Boolean:
                        _computedValue = ConvertBooleanLiteralValue(ErrCtx, _originalValue);
                        break;
 
                    case LiteralKind.Binary:
                        _computedValue = ConvertBinaryLiteralValue(ErrCtx, _originalValue); 
                        break; 

                    case LiteralKind.DateTime: 
                        _computedValue = ConvertDateTimeLiteralValue(ErrCtx, _originalValue);
                        break;

                    case LiteralKind.Time: 
                        _computedValue = ConvertTimeLiteralValue(ErrCtx, _originalValue);
                        break; 
 
                    case LiteralKind.DateTimeOffset:
                        _computedValue = ConvertDateTimeOffsetLiteralValue(ErrCtx, _originalValue); 
                        break;

                    case LiteralKind.Guid:
                        _computedValue = ConvertGuidLiteralValue(ErrCtx, _originalValue); 
                        break;
 
                    case LiteralKind.Null: 
                        _computedValue = null;
                        break; 

                    default:
                        throw EntityUtil.NotSupported(System.Data.Entity.Strings.LiteralTypeNotSupported(_literalKind.ToString()));
 
                }
 
                _type = IsNullLiteral ? null : _computedValue.GetType(); 
            }
        } 

        #region Conversion Helpers
        static char[] numberSuffixes = new char[] { 'U', 'u', 'L', 'l', 'F', 'f', 'M', 'm', 'D', 'd' };
        static char[] floatTokens = new char[] { '.', 'E', 'e' }; 
        private static object ConvertNumericLiteral(ErrorContext errCtx, string numericString)
        { 
            int k = numericString.IndexOfAny(numberSuffixes); 
            if (-1 != k)
            { 
                string suffix = numericString.Substring(k).ToUpperInvariant();
                string numberPart = numericString.Substring(0, numericString.Length - suffix.Length);
                switch (suffix)
                { 
                    case "U":
                        { 
                            UInt32 value; 
                            if (!UInt32.TryParse(numberPart, NumberStyles.Integer, CultureInfo.InvariantCulture, out value))
                            { 
                                throw EntityUtil.EntitySqlError(errCtx, System.Data.Entity.Strings.CannotConvertNumericLiteral(numericString, "unsigned int"));
                            }
                            return value;
                        } 
                        ;
 
                    case "L": 
                        {
                            long value; 
                            if (!Int64.TryParse(numberPart, NumberStyles.Integer, CultureInfo.InvariantCulture, out value))
                            {
                                throw EntityUtil.EntitySqlError(errCtx, System.Data.Entity.Strings.CannotConvertNumericLiteral(numericString, "long"));
                            } 
                            return value;
                        } 
                        ; 

                    case "UL": 
                    case "LU":
                        {
                            UInt64 value;
                            if (!UInt64.TryParse(numberPart, NumberStyles.Integer, CultureInfo.InvariantCulture, out value)) 
                            {
                                throw EntityUtil.EntitySqlError(errCtx, System.Data.Entity.Strings.CannotConvertNumericLiteral(numericString, "unsigned long")); 
                            } 
                            return value;
                        } 
                        ;

                    case "F":
                        { 
                            Single value;
                            if (!Single.TryParse(numberPart, NumberStyles.Float, CultureInfo.InvariantCulture, out value)) 
                            { 
                                throw EntityUtil.EntitySqlError(errCtx, System.Data.Entity.Strings.CannotConvertNumericLiteral(numericString, "float"));
                            } 
                            return value;
                        }
                        ;
 
                    case "M":
                        { 
                            Decimal value; 
                            if (!Decimal.TryParse(numberPart, NumberStyles.AllowLeadingSign | NumberStyles.AllowDecimalPoint, CultureInfo.InvariantCulture, out value))
                            { 
                                throw EntityUtil.EntitySqlError(errCtx, System.Data.Entity.Strings.CannotConvertNumericLiteral(numericString, "decimal"));
                            }
                            return value;
                        } 
                        ;
 
                    case "D": 
                        {
                            Double value; 
                            if (!Double.TryParse(numberPart, NumberStyles.Float, CultureInfo.InvariantCulture, out value))
                            {
                                throw EntityUtil.EntitySqlError(errCtx, System.Data.Entity.Strings.CannotConvertNumericLiteral(numericString, "double"));
                            } 
                            return value;
                        } 
                        ; 

                } 
            }

            //
            // If hit this point, try default conversion 
            //
            return DefaultNumericConversion(numericString, errCtx); 
        } 

        ///  
        /// Performs conversion of numeric strings that have no type suffix hint.
        /// 
        private static object DefaultNumericConversion(string numericString, ErrorContext errCtx)
        { 

            if (-1 != numericString.IndexOfAny(floatTokens)) 
            { 
                Double value;
                if (!Double.TryParse(numericString, NumberStyles.Float, CultureInfo.InvariantCulture, out value)) 
                {
                    throw EntityUtil.EntitySqlError(errCtx, System.Data.Entity.Strings.CannotConvertNumericLiteral(numericString, "double"));
                }
 
                return value;
            } 
            else 
            {
                Int32 int32Value; 
                if (Int32.TryParse(numericString, NumberStyles.Integer, CultureInfo.InvariantCulture, out int32Value))
                {
                    return int32Value;
                } 

                Int64 int64Value; 
                if (!Int64.TryParse(numericString, NumberStyles.Integer, CultureInfo.InvariantCulture, out int64Value)) 
                {
                    throw EntityUtil.EntitySqlError(errCtx, System.Data.Entity.Strings.CannotConvertNumericLiteral(numericString, "long")); 
                }

                return int64Value;
            } 

        } 
 
        /// 
        /// Converts boolean literal value. 
        /// 
        private static bool ConvertBooleanLiteralValue(ErrorContext errCtx, string booleanLiteralValue)
        {
            bool result = false; 
            if (!Boolean.TryParse(booleanLiteralValue, out result))
            { 
                throw EntityUtil.EntitySqlError(errCtx, System.Data.Entity.Strings.InvalidLiteralFormat("Boolean", booleanLiteralValue)); 
            }
            return result; 
        }

        /// 
        /// Returns the string literal value. 
        /// 
        private static string GetStringLiteralValue(string stringLiteralValue, bool isUnicode) 
        { 
            Debug.Assert(stringLiteralValue.Length >= 2);
            Debug.Assert(isUnicode == ('N' == stringLiteralValue[0]), "invalid string literal value"); 

            int startIndex = (isUnicode ? 2 : 1);
            char delimiter = stringLiteralValue[startIndex - 1];
 
            // NOTE: this is not a precondition validation. This validation is for security purposes based on the
            // paranoid assumption that all input is evil. we should not see this exception under normal 
            // conditions. 
            if (delimiter != '\'' && delimiter != '\"')
            { 
                throw EntityUtil.EntitySqlError(System.Data.Entity.Strings.MalformedStringLiteralPayload);
            }

            string result = ""; 

            // NOTE: this is not a precondition validation. This validation is for security purposes based on the 
            // paranoid assumption that all input is evil. we should not see this exception under normal 
            // conditions.
            int before = stringLiteralValue.Split(new char[] { delimiter }).Length - 1; 
            Debug.Assert(before % 2 == 0, "must have an even number of delimiters in the string literal");
            if (0 != (before % 2))
            {
                throw EntityUtil.EntitySqlError(System.Data.Entity.Strings.MalformedStringLiteralPayload); 
            }
 
            // 
            // Extract the payload and replace escaped chars that match the envelope delimiter
            // 
            result = stringLiteralValue.Substring(startIndex, stringLiteralValue.Length - (1 + startIndex));
            result = result.Replace(new String(delimiter, 2), new String(delimiter, 1));

            // NOTE: this is not a precondition validation. This validation is for security purposes based on the 
            // paranoid assumption that all input is evil. we should not see this exception under normal
            // conditions. 
            int after = result.Split(new char[] { delimiter }).Length - 1; 
            Debug.Assert(after == (before - 2) / 2);
            if ((after != ((before - 2) / 2))) 
            {
                throw EntityUtil.EntitySqlError(System.Data.Entity.Strings.MalformedStringLiteralPayload);
            }
 
            return result;
        } 
 
        /// 
        /// Converts hex string to byte array. 
        /// 
        private static byte[] ConvertBinaryLiteralValue(ErrorContext errCtx, string binaryLiteralValue)
        {
            Debug.Assert(null != binaryLiteralValue, "binaryStringLiteral must not be null"); 

            if (String.IsNullOrEmpty(binaryLiteralValue)) 
            { 
                return _emptyByteArray;
            } 

            int startIndex = 0;
            int endIndex = binaryLiteralValue.Length - 1;
            Debug.Assert(startIndex <= endIndex, "startIndex <= endIndex"); 
            int binaryStringLen = endIndex - startIndex + 1;
            int byteArrayLen = binaryStringLen / 2; 
            bool hasOddBytes = 0 != (binaryStringLen % 2); 
            if (hasOddBytes)
            { 
                byteArrayLen++;
            }

            byte[] binaryValue = new byte[byteArrayLen]; 
            int arrayIndex = 0;
            if (hasOddBytes) 
            { 
                binaryValue[arrayIndex++] = (byte)HexDigitToBinaryValue(binaryLiteralValue[startIndex++]);
            } 

            while (startIndex < endIndex)
            {
                binaryValue[arrayIndex++] = (byte)((HexDigitToBinaryValue(binaryLiteralValue[startIndex++]) << 4) | HexDigitToBinaryValue(binaryLiteralValue[startIndex++])); 
            }
 
            return binaryValue; 
        }
 
        /// 
        /// Parse single hex char.
        /// PRECONDITION - hexChar must be a valid hex digit.
        ///  
        private static int HexDigitToBinaryValue(char hexChar)
        { 
            if (hexChar >= '0' && hexChar <= '9') return (int)(hexChar - '0'); 
            if (hexChar >= 'A' && hexChar <= 'F') return (int)(hexChar - 'A') + 10;
            if (hexChar >= 'a' && hexChar <= 'f') return (int)(hexChar - 'a') + 10; 
            Debug.Assert(false, "Invalid Hexadecimal Digit");
            throw EntityUtil.ArgumentOutOfRange("hexadecimal digit is not valid");
        }
 

        static readonly char[] _datetimeSeparators = new char[] { ' ', ':', '-', '.' }; 
        static readonly char[] _dateSeparators = new char[] { '-' }; 
        static readonly char[] _timeSeparators = new char[] { ':', '.' };
        static readonly char[] _datetimeOffsetSeparators = new char[] { ' ', ':', '-', '.', '+', '-' }; 

        /// 
        /// Converts datetime literal value.
        ///  
        private static DateTime ConvertDateTimeLiteralValue(ErrorContext errCtx, string datetimeLiteralValue)
        { 
            string[] datetimeParts = datetimeLiteralValue.Split(_datetimeSeparators, StringSplitOptions.RemoveEmptyEntries); 

            Debug.Assert(datetimeParts.Length >= 5, "datetime literal value must have at least 5 parts"); 

            int year;
            int month;
            int day; 
            GetDateParts(datetimeLiteralValue, datetimeParts, out year, out month, out day);
            int hour; 
            int minute; 
            int second;
            int ticks; 
            GetTimeParts(datetimeLiteralValue, datetimeParts, 3, out hour, out minute, out second, out ticks);

            Debug.Assert(year >= 1 && year <= 9999);
            Debug.Assert(month >= 1 && month <= 12); 
            Debug.Assert(day >= 1 && day <= 31);
            Debug.Assert(hour >= 0 && hour <= 24); 
            Debug.Assert(minute >= 0 && minute <= 59); 
            Debug.Assert(second >= 0 && second <= 59);
            Debug.Assert(ticks >= 0 && ticks <= 9999999); 
            DateTime dateTime = new DateTime(year, month, day, hour, minute, second, 0);
            dateTime = dateTime.AddTicks(ticks);
            return dateTime;
        } 

        private static DateTimeOffset ConvertDateTimeOffsetLiteralValue(ErrorContext errCtx, string datetimeLiteralValue) 
        { 
            string[] datetimeParts = datetimeLiteralValue.Split(_datetimeOffsetSeparators, StringSplitOptions.RemoveEmptyEntries);
 
            Debug.Assert(datetimeParts.Length >= 7, "datetime literal value must have at least 7 parts");

            int year;
            int month; 
            int day;
            GetDateParts(datetimeLiteralValue, datetimeParts, out year, out month, out day); 
            int hour; 
            int minute;
            int second; 
            int ticks;
            //Copy the time parts into a different array since the last two parts will be handled in this method.
            string[] timeParts = new String[datetimeParts.Length - 2];
            Array.Copy(datetimeParts, timeParts, datetimeParts.Length - 2); 
            GetTimeParts(datetimeLiteralValue, timeParts, 3, out hour, out minute, out second, out ticks);
 
            Debug.Assert(year >= 1 && year <= 9999); 
            Debug.Assert(month >= 1 && month <= 12);
            Debug.Assert(day >= 1 && day <= 31); 
            Debug.Assert(hour >= 0 && hour <= 24);
            Debug.Assert(minute >= 0 && minute <= 59);
            Debug.Assert(second >= 0 && second <= 59);
            Debug.Assert(ticks >= 0 && ticks <= 9999999); 
            int offsetHours = Int32.Parse(datetimeParts[datetimeParts.Length - 2], NumberStyles.Integer, CultureInfo.InvariantCulture);
            int offsetMinutes = Int32.Parse(datetimeParts[datetimeParts.Length - 1], NumberStyles.Integer, CultureInfo.InvariantCulture); 
            TimeSpan offsetTimeSpan = new TimeSpan(offsetHours, offsetMinutes, 0); 

            //If DateTimeOffset had a negative offset, we should negate the timespan 
            if (datetimeLiteralValue.IndexOf('+') == -1)
            {
                offsetTimeSpan = offsetTimeSpan.Negate();
            } 
            DateTime dateTime = new DateTime(year, month, day, hour, minute, second, 0);
            dateTime = dateTime.AddTicks(ticks); 
 
            try
            { 
                return new DateTimeOffset(dateTime, offsetTimeSpan);
            }
            catch (ArgumentOutOfRangeException e)
            { 
                throw EntityUtil.EntitySqlError(errCtx, System.Data.Entity.Strings.InvalidDateTimeOffsetLiteral(datetimeLiteralValue), e);
            } 
        } 

        ///  
        /// Converts time literal value.
        /// 
        private static TimeSpan ConvertTimeLiteralValue(ErrorContext errCtx, string datetimeLiteralValue)
        { 
            string[] datetimeParts = datetimeLiteralValue.Split(_datetimeSeparators, StringSplitOptions.RemoveEmptyEntries);
 
            Debug.Assert(datetimeParts.Length >= 2, "time literal value must have at least 2 parts"); 

            int hour; 
            int minute;
            int second;
            int ticks;
            GetTimeParts(datetimeLiteralValue, datetimeParts, 0, out hour, out minute, out second, out ticks); 

            Debug.Assert(hour >= 0 && hour <= 24); 
            Debug.Assert(minute >= 0 && minute <= 59); 
            Debug.Assert(second >= 0 && second <= 59);
            Debug.Assert(ticks >= 0 && ticks <= 9999999); 
            TimeSpan ts = new TimeSpan(hour, minute, second);
            ts = ts.Add(new TimeSpan(ticks));
            return ts;
        } 

        private static void GetTimeParts(string datetimeLiteralValue, string[] datetimeParts, int timePartStartIndex, out int hour, out int minute, out int second, out int ticks) 
        { 
            hour = Int32.Parse(datetimeParts[timePartStartIndex], NumberStyles.Integer, CultureInfo.InvariantCulture);
            if (hour > 23) 
            {
                throw EntityUtil.EntitySqlError(System.Data.Entity.Strings.InvalidHour(datetimeParts[timePartStartIndex], datetimeLiteralValue));
            }
            minute = Int32.Parse(datetimeParts[++timePartStartIndex], NumberStyles.Integer, CultureInfo.InvariantCulture); 
            if (minute > 59)
            { 
                throw EntityUtil.EntitySqlError(System.Data.Entity.Strings.InvalidMinute(datetimeParts[timePartStartIndex], datetimeLiteralValue)); 
            }
            second = 0; 
            ticks = 0;
            timePartStartIndex++;
            if (datetimeParts.Length > timePartStartIndex)
            { 
                second = Int32.Parse(datetimeParts[timePartStartIndex], NumberStyles.Integer, CultureInfo.InvariantCulture);
                if (second > 59) 
                { 
                    throw EntityUtil.EntitySqlError(System.Data.Entity.Strings.InvalidSecond(datetimeParts[timePartStartIndex], datetimeLiteralValue));
                } 
                timePartStartIndex++;
                if (datetimeParts.Length > timePartStartIndex)
                {
                    //We need fractional time part to be seven digits 
                    string ticksString = datetimeParts[timePartStartIndex].PadRight(7, '0');
                    ticks = Int32.Parse(ticksString, NumberStyles.Integer, CultureInfo.InvariantCulture); 
                } 

            } 
        }

        private static void GetDateParts(string datetimeLiteralValue, string[] datetimeParts, out int year, out int month, out int day)
        { 
            year = Int32.Parse(datetimeParts[0], NumberStyles.Integer, CultureInfo.InvariantCulture);
            if (year < 1 || year > 9999) 
            { 
                throw EntityUtil.EntitySqlError(System.Data.Entity.Strings.InvalidYear(datetimeParts[0], datetimeLiteralValue));
            } 
            month = Int32.Parse(datetimeParts[1], NumberStyles.Integer, CultureInfo.InvariantCulture);
            if (month < 1 || month > 12)
            {
                throw EntityUtil.EntitySqlError(System.Data.Entity.Strings.InvalidMonth(datetimeParts[1], datetimeLiteralValue)); 
            }
            day = Int32.Parse(datetimeParts[2], NumberStyles.Integer, CultureInfo.InvariantCulture); 
            if (day < 1) 
            {
                throw EntityUtil.EntitySqlError(System.Data.Entity.Strings.InvalidDay(datetimeParts[2], datetimeLiteralValue)); 
            }
            if (day > DateTime.DaysInMonth(year, month))
            {
                throw EntityUtil.EntitySqlError(System.Data.Entity.Strings.InvalidDayInMonth(datetimeParts[2], datetimeParts[1], datetimeLiteralValue)); 
            }
        } 
 
        /// 
        /// Converts guid literal value. 
        /// 
        private static Guid ConvertGuidLiteralValue(ErrorContext errCtx, string guidLiteralValue)
        {
            return new Guid(guidLiteralValue); 
        }
        #endregion 
    } 
}

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

namespace System.Data.Common.EntitySql.AST 
{
    using System;
    using System.Globalization;
    using System.Collections; 
    using System.Collections.Generic;
    using System.Diagnostics; 
    using System.Text; 

    ///  
    /// Defines literal value kind, including the eSQL untyped NULL.
    /// 
    internal enum LiteralKind
    { 
        Number,
        String, 
        UnicodeString, 
        Boolean,
        Binary, 
        DateTime,
        Time,
        DateTimeOffset,
        Guid, 
        Null
    } 
 
    /// 
    /// Represents a literal ast node. 
    /// 
    internal sealed class Literal : Node
    {
        private readonly LiteralKind _literalKind; 
        private string _originalValue;
        private bool _wasValueComputed = false; 
        private object _computedValue; 
        private Type _type;
        private static readonly Byte[] _emptyByteArray = new byte[0]; 

        /// 
        /// Initializes a literal ast node.
        ///  
        /// literal value in cql string representation
        /// literal value class 
        /// query 
        /// input position
        internal Literal(string originalValue, LiteralKind kind, string query, int inputPos) 
            : base(query, inputPos)
        {
            _originalValue = originalValue;
            _literalKind = kind; 
        }
 
        ///  
        /// Static factory to create boolean literals by value only.
        ///  
        /// 
        internal static Literal NewBooleanLiteral(bool value) { return new Literal(value); }

        private Literal(bool boolLiteral) 
            : base(null, 0)
        { 
            _wasValueComputed = true; 
            _originalValue = String.Empty;
            _computedValue = boolLiteral; 
            _type = typeof(System.Boolean);
        }

        ///  
        /// True if literal is a number.
        ///  
        internal bool IsNumber 
        {
            get 
            {
                return (_literalKind == LiteralKind.Number);
            }
        } 

        ///  
        /// True if literal is a signed number. 
        /// 
        internal bool IsSignedNumber 
        {
            get
            {
                return IsNumber && (_originalValue[0] == '-' || _originalValue[0] == '+'); 
            }
        } 
 
        /// 
        /// True if literal is a string. 
        /// 
        /// 
        /// 
        ///  
        internal bool IsString
        { 
            get 
            {
                return _literalKind == LiteralKind.String || _literalKind == LiteralKind.UnicodeString; 
            }
        }

        ///  
        /// True if literal is a unicode string.
        ///  
        ///  
        /// 
        ///  
        internal bool IsUnicodeString
        {
            get
            { 
                return _literalKind == LiteralKind.UnicodeString;
            } 
        } 

        ///  
        /// True if literal is the eSQL untyped null.
        /// 
        /// 
        ///  
        /// 
        internal bool IsNullLiteral 
        { 
            get
            { 
                return _literalKind == LiteralKind.Null;
            }
        }
 
        /// 
        /// Returns the original literal value. 
        ///  
        internal string OriginalValue
        { 
            get
            {
                return _originalValue;
            } 
        }
 
        ///  
        /// Prefix a numeric literal with a sign.
        ///  
        internal void PrefixSign(string sign)
        {
            System.Diagnostics.Debug.Assert(IsNumber && !IsSignedNumber);
            System.Diagnostics.Debug.Assert(sign[0] == '-' || sign[0] == '+', "sign symbol must be + or -"); 
            System.Diagnostics.Debug.Assert(_computedValue == null);
 
            _originalValue = sign + _originalValue; 
        }
 
        #region Computed members
        /// 
        /// Returns literal converted value.
        ///  
        /// 
        ///  
        ///  
        internal object Value
        { 
            get
            {
                ComputeValue();
 
                return _computedValue;
            } 
        } 

        ///  
        /// Returns literal value type. If value is eSQL untyped null, returns null.
        /// 
        /// 
        ///  
        /// 
        internal Type Type 
        { 
            get
            { 
                ComputeValue();

                return _type;
            } 
        }
        #endregion 
 
        private void ComputeValue()
        { 
            if (!_wasValueComputed)
            {
                _wasValueComputed = true;
 
                switch (_literalKind)
                { 
                    case LiteralKind.Number: 
                        _computedValue = ConvertNumericLiteral(ErrCtx, _originalValue);
                        break; 

                    case LiteralKind.String:
                        _computedValue = GetStringLiteralValue(_originalValue, false /* isUnicode */);
                        break; 

                    case LiteralKind.UnicodeString: 
                        _computedValue = GetStringLiteralValue(_originalValue, true /* isUnicode */); 
                        break;
 
                    case LiteralKind.Boolean:
                        _computedValue = ConvertBooleanLiteralValue(ErrCtx, _originalValue);
                        break;
 
                    case LiteralKind.Binary:
                        _computedValue = ConvertBinaryLiteralValue(ErrCtx, _originalValue); 
                        break; 

                    case LiteralKind.DateTime: 
                        _computedValue = ConvertDateTimeLiteralValue(ErrCtx, _originalValue);
                        break;

                    case LiteralKind.Time: 
                        _computedValue = ConvertTimeLiteralValue(ErrCtx, _originalValue);
                        break; 
 
                    case LiteralKind.DateTimeOffset:
                        _computedValue = ConvertDateTimeOffsetLiteralValue(ErrCtx, _originalValue); 
                        break;

                    case LiteralKind.Guid:
                        _computedValue = ConvertGuidLiteralValue(ErrCtx, _originalValue); 
                        break;
 
                    case LiteralKind.Null: 
                        _computedValue = null;
                        break; 

                    default:
                        throw EntityUtil.NotSupported(System.Data.Entity.Strings.LiteralTypeNotSupported(_literalKind.ToString()));
 
                }
 
                _type = IsNullLiteral ? null : _computedValue.GetType(); 
            }
        } 

        #region Conversion Helpers
        static char[] numberSuffixes = new char[] { 'U', 'u', 'L', 'l', 'F', 'f', 'M', 'm', 'D', 'd' };
        static char[] floatTokens = new char[] { '.', 'E', 'e' }; 
        private static object ConvertNumericLiteral(ErrorContext errCtx, string numericString)
        { 
            int k = numericString.IndexOfAny(numberSuffixes); 
            if (-1 != k)
            { 
                string suffix = numericString.Substring(k).ToUpperInvariant();
                string numberPart = numericString.Substring(0, numericString.Length - suffix.Length);
                switch (suffix)
                { 
                    case "U":
                        { 
                            UInt32 value; 
                            if (!UInt32.TryParse(numberPart, NumberStyles.Integer, CultureInfo.InvariantCulture, out value))
                            { 
                                throw EntityUtil.EntitySqlError(errCtx, System.Data.Entity.Strings.CannotConvertNumericLiteral(numericString, "unsigned int"));
                            }
                            return value;
                        } 
                        ;
 
                    case "L": 
                        {
                            long value; 
                            if (!Int64.TryParse(numberPart, NumberStyles.Integer, CultureInfo.InvariantCulture, out value))
                            {
                                throw EntityUtil.EntitySqlError(errCtx, System.Data.Entity.Strings.CannotConvertNumericLiteral(numericString, "long"));
                            } 
                            return value;
                        } 
                        ; 

                    case "UL": 
                    case "LU":
                        {
                            UInt64 value;
                            if (!UInt64.TryParse(numberPart, NumberStyles.Integer, CultureInfo.InvariantCulture, out value)) 
                            {
                                throw EntityUtil.EntitySqlError(errCtx, System.Data.Entity.Strings.CannotConvertNumericLiteral(numericString, "unsigned long")); 
                            } 
                            return value;
                        } 
                        ;

                    case "F":
                        { 
                            Single value;
                            if (!Single.TryParse(numberPart, NumberStyles.Float, CultureInfo.InvariantCulture, out value)) 
                            { 
                                throw EntityUtil.EntitySqlError(errCtx, System.Data.Entity.Strings.CannotConvertNumericLiteral(numericString, "float"));
                            } 
                            return value;
                        }
                        ;
 
                    case "M":
                        { 
                            Decimal value; 
                            if (!Decimal.TryParse(numberPart, NumberStyles.AllowLeadingSign | NumberStyles.AllowDecimalPoint, CultureInfo.InvariantCulture, out value))
                            { 
                                throw EntityUtil.EntitySqlError(errCtx, System.Data.Entity.Strings.CannotConvertNumericLiteral(numericString, "decimal"));
                            }
                            return value;
                        } 
                        ;
 
                    case "D": 
                        {
                            Double value; 
                            if (!Double.TryParse(numberPart, NumberStyles.Float, CultureInfo.InvariantCulture, out value))
                            {
                                throw EntityUtil.EntitySqlError(errCtx, System.Data.Entity.Strings.CannotConvertNumericLiteral(numericString, "double"));
                            } 
                            return value;
                        } 
                        ; 

                } 
            }

            //
            // If hit this point, try default conversion 
            //
            return DefaultNumericConversion(numericString, errCtx); 
        } 

        ///  
        /// Performs conversion of numeric strings that have no type suffix hint.
        /// 
        private static object DefaultNumericConversion(string numericString, ErrorContext errCtx)
        { 

            if (-1 != numericString.IndexOfAny(floatTokens)) 
            { 
                Double value;
                if (!Double.TryParse(numericString, NumberStyles.Float, CultureInfo.InvariantCulture, out value)) 
                {
                    throw EntityUtil.EntitySqlError(errCtx, System.Data.Entity.Strings.CannotConvertNumericLiteral(numericString, "double"));
                }
 
                return value;
            } 
            else 
            {
                Int32 int32Value; 
                if (Int32.TryParse(numericString, NumberStyles.Integer, CultureInfo.InvariantCulture, out int32Value))
                {
                    return int32Value;
                } 

                Int64 int64Value; 
                if (!Int64.TryParse(numericString, NumberStyles.Integer, CultureInfo.InvariantCulture, out int64Value)) 
                {
                    throw EntityUtil.EntitySqlError(errCtx, System.Data.Entity.Strings.CannotConvertNumericLiteral(numericString, "long")); 
                }

                return int64Value;
            } 

        } 
 
        /// 
        /// Converts boolean literal value. 
        /// 
        private static bool ConvertBooleanLiteralValue(ErrorContext errCtx, string booleanLiteralValue)
        {
            bool result = false; 
            if (!Boolean.TryParse(booleanLiteralValue, out result))
            { 
                throw EntityUtil.EntitySqlError(errCtx, System.Data.Entity.Strings.InvalidLiteralFormat("Boolean", booleanLiteralValue)); 
            }
            return result; 
        }

        /// 
        /// Returns the string literal value. 
        /// 
        private static string GetStringLiteralValue(string stringLiteralValue, bool isUnicode) 
        { 
            Debug.Assert(stringLiteralValue.Length >= 2);
            Debug.Assert(isUnicode == ('N' == stringLiteralValue[0]), "invalid string literal value"); 

            int startIndex = (isUnicode ? 2 : 1);
            char delimiter = stringLiteralValue[startIndex - 1];
 
            // NOTE: this is not a precondition validation. This validation is for security purposes based on the
            // paranoid assumption that all input is evil. we should not see this exception under normal 
            // conditions. 
            if (delimiter != '\'' && delimiter != '\"')
            { 
                throw EntityUtil.EntitySqlError(System.Data.Entity.Strings.MalformedStringLiteralPayload);
            }

            string result = ""; 

            // NOTE: this is not a precondition validation. This validation is for security purposes based on the 
            // paranoid assumption that all input is evil. we should not see this exception under normal 
            // conditions.
            int before = stringLiteralValue.Split(new char[] { delimiter }).Length - 1; 
            Debug.Assert(before % 2 == 0, "must have an even number of delimiters in the string literal");
            if (0 != (before % 2))
            {
                throw EntityUtil.EntitySqlError(System.Data.Entity.Strings.MalformedStringLiteralPayload); 
            }
 
            // 
            // Extract the payload and replace escaped chars that match the envelope delimiter
            // 
            result = stringLiteralValue.Substring(startIndex, stringLiteralValue.Length - (1 + startIndex));
            result = result.Replace(new String(delimiter, 2), new String(delimiter, 1));

            // NOTE: this is not a precondition validation. This validation is for security purposes based on the 
            // paranoid assumption that all input is evil. we should not see this exception under normal
            // conditions. 
            int after = result.Split(new char[] { delimiter }).Length - 1; 
            Debug.Assert(after == (before - 2) / 2);
            if ((after != ((before - 2) / 2))) 
            {
                throw EntityUtil.EntitySqlError(System.Data.Entity.Strings.MalformedStringLiteralPayload);
            }
 
            return result;
        } 
 
        /// 
        /// Converts hex string to byte array. 
        /// 
        private static byte[] ConvertBinaryLiteralValue(ErrorContext errCtx, string binaryLiteralValue)
        {
            Debug.Assert(null != binaryLiteralValue, "binaryStringLiteral must not be null"); 

            if (String.IsNullOrEmpty(binaryLiteralValue)) 
            { 
                return _emptyByteArray;
            } 

            int startIndex = 0;
            int endIndex = binaryLiteralValue.Length - 1;
            Debug.Assert(startIndex <= endIndex, "startIndex <= endIndex"); 
            int binaryStringLen = endIndex - startIndex + 1;
            int byteArrayLen = binaryStringLen / 2; 
            bool hasOddBytes = 0 != (binaryStringLen % 2); 
            if (hasOddBytes)
            { 
                byteArrayLen++;
            }

            byte[] binaryValue = new byte[byteArrayLen]; 
            int arrayIndex = 0;
            if (hasOddBytes) 
            { 
                binaryValue[arrayIndex++] = (byte)HexDigitToBinaryValue(binaryLiteralValue[startIndex++]);
            } 

            while (startIndex < endIndex)
            {
                binaryValue[arrayIndex++] = (byte)((HexDigitToBinaryValue(binaryLiteralValue[startIndex++]) << 4) | HexDigitToBinaryValue(binaryLiteralValue[startIndex++])); 
            }
 
            return binaryValue; 
        }
 
        /// 
        /// Parse single hex char.
        /// PRECONDITION - hexChar must be a valid hex digit.
        ///  
        private static int HexDigitToBinaryValue(char hexChar)
        { 
            if (hexChar >= '0' && hexChar <= '9') return (int)(hexChar - '0'); 
            if (hexChar >= 'A' && hexChar <= 'F') return (int)(hexChar - 'A') + 10;
            if (hexChar >= 'a' && hexChar <= 'f') return (int)(hexChar - 'a') + 10; 
            Debug.Assert(false, "Invalid Hexadecimal Digit");
            throw EntityUtil.ArgumentOutOfRange("hexadecimal digit is not valid");
        }
 

        static readonly char[] _datetimeSeparators = new char[] { ' ', ':', '-', '.' }; 
        static readonly char[] _dateSeparators = new char[] { '-' }; 
        static readonly char[] _timeSeparators = new char[] { ':', '.' };
        static readonly char[] _datetimeOffsetSeparators = new char[] { ' ', ':', '-', '.', '+', '-' }; 

        /// 
        /// Converts datetime literal value.
        ///  
        private static DateTime ConvertDateTimeLiteralValue(ErrorContext errCtx, string datetimeLiteralValue)
        { 
            string[] datetimeParts = datetimeLiteralValue.Split(_datetimeSeparators, StringSplitOptions.RemoveEmptyEntries); 

            Debug.Assert(datetimeParts.Length >= 5, "datetime literal value must have at least 5 parts"); 

            int year;
            int month;
            int day; 
            GetDateParts(datetimeLiteralValue, datetimeParts, out year, out month, out day);
            int hour; 
            int minute; 
            int second;
            int ticks; 
            GetTimeParts(datetimeLiteralValue, datetimeParts, 3, out hour, out minute, out second, out ticks);

            Debug.Assert(year >= 1 && year <= 9999);
            Debug.Assert(month >= 1 && month <= 12); 
            Debug.Assert(day >= 1 && day <= 31);
            Debug.Assert(hour >= 0 && hour <= 24); 
            Debug.Assert(minute >= 0 && minute <= 59); 
            Debug.Assert(second >= 0 && second <= 59);
            Debug.Assert(ticks >= 0 && ticks <= 9999999); 
            DateTime dateTime = new DateTime(year, month, day, hour, minute, second, 0);
            dateTime = dateTime.AddTicks(ticks);
            return dateTime;
        } 

        private static DateTimeOffset ConvertDateTimeOffsetLiteralValue(ErrorContext errCtx, string datetimeLiteralValue) 
        { 
            string[] datetimeParts = datetimeLiteralValue.Split(_datetimeOffsetSeparators, StringSplitOptions.RemoveEmptyEntries);
 
            Debug.Assert(datetimeParts.Length >= 7, "datetime literal value must have at least 7 parts");

            int year;
            int month; 
            int day;
            GetDateParts(datetimeLiteralValue, datetimeParts, out year, out month, out day); 
            int hour; 
            int minute;
            int second; 
            int ticks;
            //Copy the time parts into a different array since the last two parts will be handled in this method.
            string[] timeParts = new String[datetimeParts.Length - 2];
            Array.Copy(datetimeParts, timeParts, datetimeParts.Length - 2); 
            GetTimeParts(datetimeLiteralValue, timeParts, 3, out hour, out minute, out second, out ticks);
 
            Debug.Assert(year >= 1 && year <= 9999); 
            Debug.Assert(month >= 1 && month <= 12);
            Debug.Assert(day >= 1 && day <= 31); 
            Debug.Assert(hour >= 0 && hour <= 24);
            Debug.Assert(minute >= 0 && minute <= 59);
            Debug.Assert(second >= 0 && second <= 59);
            Debug.Assert(ticks >= 0 && ticks <= 9999999); 
            int offsetHours = Int32.Parse(datetimeParts[datetimeParts.Length - 2], NumberStyles.Integer, CultureInfo.InvariantCulture);
            int offsetMinutes = Int32.Parse(datetimeParts[datetimeParts.Length - 1], NumberStyles.Integer, CultureInfo.InvariantCulture); 
            TimeSpan offsetTimeSpan = new TimeSpan(offsetHours, offsetMinutes, 0); 

            //If DateTimeOffset had a negative offset, we should negate the timespan 
            if (datetimeLiteralValue.IndexOf('+') == -1)
            {
                offsetTimeSpan = offsetTimeSpan.Negate();
            } 
            DateTime dateTime = new DateTime(year, month, day, hour, minute, second, 0);
            dateTime = dateTime.AddTicks(ticks); 
 
            try
            { 
                return new DateTimeOffset(dateTime, offsetTimeSpan);
            }
            catch (ArgumentOutOfRangeException e)
            { 
                throw EntityUtil.EntitySqlError(errCtx, System.Data.Entity.Strings.InvalidDateTimeOffsetLiteral(datetimeLiteralValue), e);
            } 
        } 

        ///  
        /// Converts time literal value.
        /// 
        private static TimeSpan ConvertTimeLiteralValue(ErrorContext errCtx, string datetimeLiteralValue)
        { 
            string[] datetimeParts = datetimeLiteralValue.Split(_datetimeSeparators, StringSplitOptions.RemoveEmptyEntries);
 
            Debug.Assert(datetimeParts.Length >= 2, "time literal value must have at least 2 parts"); 

            int hour; 
            int minute;
            int second;
            int ticks;
            GetTimeParts(datetimeLiteralValue, datetimeParts, 0, out hour, out minute, out second, out ticks); 

            Debug.Assert(hour >= 0 && hour <= 24); 
            Debug.Assert(minute >= 0 && minute <= 59); 
            Debug.Assert(second >= 0 && second <= 59);
            Debug.Assert(ticks >= 0 && ticks <= 9999999); 
            TimeSpan ts = new TimeSpan(hour, minute, second);
            ts = ts.Add(new TimeSpan(ticks));
            return ts;
        } 

        private static void GetTimeParts(string datetimeLiteralValue, string[] datetimeParts, int timePartStartIndex, out int hour, out int minute, out int second, out int ticks) 
        { 
            hour = Int32.Parse(datetimeParts[timePartStartIndex], NumberStyles.Integer, CultureInfo.InvariantCulture);
            if (hour > 23) 
            {
                throw EntityUtil.EntitySqlError(System.Data.Entity.Strings.InvalidHour(datetimeParts[timePartStartIndex], datetimeLiteralValue));
            }
            minute = Int32.Parse(datetimeParts[++timePartStartIndex], NumberStyles.Integer, CultureInfo.InvariantCulture); 
            if (minute > 59)
            { 
                throw EntityUtil.EntitySqlError(System.Data.Entity.Strings.InvalidMinute(datetimeParts[timePartStartIndex], datetimeLiteralValue)); 
            }
            second = 0; 
            ticks = 0;
            timePartStartIndex++;
            if (datetimeParts.Length > timePartStartIndex)
            { 
                second = Int32.Parse(datetimeParts[timePartStartIndex], NumberStyles.Integer, CultureInfo.InvariantCulture);
                if (second > 59) 
                { 
                    throw EntityUtil.EntitySqlError(System.Data.Entity.Strings.InvalidSecond(datetimeParts[timePartStartIndex], datetimeLiteralValue));
                } 
                timePartStartIndex++;
                if (datetimeParts.Length > timePartStartIndex)
                {
                    //We need fractional time part to be seven digits 
                    string ticksString = datetimeParts[timePartStartIndex].PadRight(7, '0');
                    ticks = Int32.Parse(ticksString, NumberStyles.Integer, CultureInfo.InvariantCulture); 
                } 

            } 
        }

        private static void GetDateParts(string datetimeLiteralValue, string[] datetimeParts, out int year, out int month, out int day)
        { 
            year = Int32.Parse(datetimeParts[0], NumberStyles.Integer, CultureInfo.InvariantCulture);
            if (year < 1 || year > 9999) 
            { 
                throw EntityUtil.EntitySqlError(System.Data.Entity.Strings.InvalidYear(datetimeParts[0], datetimeLiteralValue));
            } 
            month = Int32.Parse(datetimeParts[1], NumberStyles.Integer, CultureInfo.InvariantCulture);
            if (month < 1 || month > 12)
            {
                throw EntityUtil.EntitySqlError(System.Data.Entity.Strings.InvalidMonth(datetimeParts[1], datetimeLiteralValue)); 
            }
            day = Int32.Parse(datetimeParts[2], NumberStyles.Integer, CultureInfo.InvariantCulture); 
            if (day < 1) 
            {
                throw EntityUtil.EntitySqlError(System.Data.Entity.Strings.InvalidDay(datetimeParts[2], datetimeLiteralValue)); 
            }
            if (day > DateTime.DaysInMonth(year, month))
            {
                throw EntityUtil.EntitySqlError(System.Data.Entity.Strings.InvalidDayInMonth(datetimeParts[2], datetimeParts[1], datetimeLiteralValue)); 
            }
        } 
 
        /// 
        /// Converts guid literal value. 
        /// 
        private static Guid ConvertGuidLiteralValue(ErrorContext errCtx, string guidLiteralValue)
        {
            return new Guid(guidLiteralValue); 
        }
        #endregion 
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
                        

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