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Number.Parsing.cs
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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.Globalization;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using Internal.Runtime.CompilerServices;
namespace System
{
// The Parse methods provided by the numeric classes convert a
// string to a numeric value. The optional style parameter specifies the
// permitted style of the numeric string. It must be a combination of bit flags
// from the NumberStyles enumeration. The optional info parameter
// specifies the NumberFormatInfo instance to use when parsing the
// string. If the info parameter is null or omitted, the numeric
// formatting information is obtained from the current culture.
//
// Numeric strings produced by the Format methods using the Currency,
// Decimal, Engineering, Fixed point, General, or Number standard formats
// (the C, D, E, F, G, and N format specifiers) are guaranteed to be parseable
// by the Parse methods if the NumberStyles.Any style is
// specified. Note, however, that the Parse methods do not accept
// NaNs or Infinities.
internal static partial class Number
{
private const int Int32Precision = 10;
private const int UInt32Precision = Int32Precision;
private const int Int64Precision = 19;
private const int UInt64Precision = 20;
private const int DoubleMaxExponent = 309;
private const int DoubleMinExponent = -324;
private const int FloatingPointMaxExponent = DoubleMaxExponent;
private const int FloatingPointMinExponent = DoubleMinExponent;
private const int SingleMaxExponent = 39;
private const int SingleMinExponent = -45;
/// <summary>Map from an ASCII char to its hex value, e.g. arr['b'] == 11. 0xFF means it's not a hex digit.</summary>
internal static ReadOnlySpan<byte> CharToHexLookup => new byte[]
{
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // 15
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // 31
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // 47
0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8, 0x9, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // 63
0xFF, 0xA, 0xB, 0xC, 0xD, 0xE, 0xF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // 79
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // 95
0xFF, 0xa, 0xb, 0xc, 0xd, 0xe, 0xf // 102
};
private static unsafe bool TryNumberToInt32(ref NumberBuffer number, ref int value)
{
number.CheckConsistency();
int i = number.Scale;
if (i > Int32Precision || i < number.DigitsCount)
{
return false;
}
byte* p = number.GetDigitsPointer();
Debug.Assert(p != null);
int n = 0;
while (--i >= 0)
{
if ((uint)n > (0x7FFFFFFF / 10))
{
return false;
}
n *= 10;
if (*p != '\0')
{
n += (*p++ - '0');
}
}
if (number.IsNegative)
{
n = -n;
if (n > 0)
{
return false;
}
}
else
{
if (n < 0)
{
return false;
}
}
value = n;
return true;
}
private static unsafe bool TryNumberToInt64(ref NumberBuffer number, ref long value)
{
number.CheckConsistency();
int i = number.Scale;
if (i > Int64Precision || i < number.DigitsCount)
{
return false;
}
byte* p = number.GetDigitsPointer();
Debug.Assert(p != null);
long n = 0;
while (--i >= 0)
{
if ((ulong)n > (0x7FFFFFFFFFFFFFFF / 10))
{
return false;
}
n *= 10;
if (*p != '\0')
{
n += (*p++ - '0');
}
}
if (number.IsNegative)
{
n = -n;
if (n > 0)
{
return false;
}
}
else
{
if (n < 0)
{
return false;
}
}
value = n;
return true;
}
private static unsafe bool TryNumberToUInt32(ref NumberBuffer number, ref uint value)
{
number.CheckConsistency();
int i = number.Scale;
if (i > UInt32Precision || i < number.DigitsCount || number.IsNegative)
{
return false;
}
byte* p = number.GetDigitsPointer();
Debug.Assert(p != null);
uint n = 0;
while (--i >= 0)
{
if (n > (0xFFFFFFFF / 10))
{
return false;
}
n *= 10;
if (*p != '\0')
{
uint newN = n + (uint)(*p++ - '0');
// Detect an overflow here...
if (newN < n)
{
return false;
}
n = newN;
}
}
value = n;
return true;
}
private static unsafe bool TryNumberToUInt64(ref NumberBuffer number, ref ulong value)
{
number.CheckConsistency();
int i = number.Scale;
if (i > UInt64Precision || i < number.DigitsCount || number.IsNegative)
{
return false;
}
byte* p = number.GetDigitsPointer();
Debug.Assert(p != null);
ulong n = 0;
while (--i >= 0)
{
if (n > (0xFFFFFFFFFFFFFFFF / 10))
{
return false;
}
n *= 10;
if (*p != '\0')
{
ulong newN = n + (ulong)(*p++ - '0');
// Detect an overflow here...
if (newN < n)
{
return false;
}
n = newN;
}
}
value = n;
return true;
}
internal static int ParseInt32(ReadOnlySpan<char> value, NumberStyles styles, NumberFormatInfo info)
{
ParsingStatus status = TryParseInt32(value, styles, info, out int result);
if (status != ParsingStatus.OK)
{
ThrowOverflowOrFormatException(status, TypeCode.Int32);
}
return result;
}
internal static long ParseInt64(ReadOnlySpan<char> value, NumberStyles styles, NumberFormatInfo info)
{
ParsingStatus status = TryParseInt64(value, styles, info, out long result);
if (status != ParsingStatus.OK)
{
ThrowOverflowOrFormatException(status, TypeCode.Int64);
}
return result;
}
internal static uint ParseUInt32(ReadOnlySpan<char> value, NumberStyles styles, NumberFormatInfo info)
{
ParsingStatus status = TryParseUInt32(value, styles, info, out uint result);
if (status != ParsingStatus.OK)
{
ThrowOverflowOrFormatException(status, TypeCode.UInt32);
}
return result;
}
internal static ulong ParseUInt64(ReadOnlySpan<char> value, NumberStyles styles, NumberFormatInfo info)
{
ParsingStatus status = TryParseUInt64(value, styles, info, out ulong result);
if (status != ParsingStatus.OK)
{
ThrowOverflowOrFormatException(status, TypeCode.UInt64);
}
return result;
}
private static unsafe bool TryParseNumber(ref char* str, char* strEnd, NumberStyles styles, ref NumberBuffer number, NumberFormatInfo info)
{
Debug.Assert(str != null);
Debug.Assert(strEnd != null);
Debug.Assert(str <= strEnd);
Debug.Assert((styles & NumberStyles.AllowHexSpecifier) == 0);
const int StateSign = 0x0001;
const int StateParens = 0x0002;
const int StateDigits = 0x0004;
const int StateNonZero = 0x0008;
const int StateDecimal = 0x0010;
const int StateCurrency = 0x0020;
Debug.Assert(number.DigitsCount == 0);
Debug.Assert(number.Scale == 0);
Debug.Assert(!number.IsNegative);
Debug.Assert(!number.HasNonZeroTail);
number.CheckConsistency();
string decSep; // decimal separator from NumberFormatInfo.
string groupSep; // group separator from NumberFormatInfo.
string? currSymbol = null; // currency symbol from NumberFormatInfo.
bool parsingCurrency = false;
if ((styles & NumberStyles.AllowCurrencySymbol) != 0)
{
currSymbol = info.CurrencySymbol;
// The idea here is to match the currency separators and on failure match the number separators to keep the perf of VB's IsNumeric fast.
// The values of decSep are setup to use the correct relevant separator (currency in the if part and decimal in the else part).
decSep = info.CurrencyDecimalSeparator;
groupSep = info.CurrencyGroupSeparator;
parsingCurrency = true;
}
else
{
decSep = info.NumberDecimalSeparator;
groupSep = info.NumberGroupSeparator;
}
int state = 0;
char* p = str;
char ch = p < strEnd ? *p : '\0';
char* next;
while (true)
{
// Eat whitespace unless we've found a sign which isn't followed by a currency symbol.
// "-Kr 1231.47" is legal but "- 1231.47" is not.
if (!IsWhite(ch) || (styles & NumberStyles.AllowLeadingWhite) == 0 || ((state & StateSign) != 0 && ((state & StateCurrency) == 0 && info.NumberNegativePattern != 2)))
{
if ((((styles & NumberStyles.AllowLeadingSign) != 0) && (state & StateSign) == 0) && ((next = MatchChars(p, strEnd, info.PositiveSign)) != null || ((next = MatchChars(p, strEnd, info.NegativeSign)) != null && (number.IsNegative = true))))
{
state |= StateSign;
p = next - 1;
}
else if (ch == '(' && ((styles & NumberStyles.AllowParentheses) != 0) && ((state & StateSign) == 0))
{
state |= StateSign | StateParens;
number.IsNegative = true;
}
else if (currSymbol != null && (next = MatchChars(p, strEnd, currSymbol)) != null)
{
state |= StateCurrency;
currSymbol = null;
// We already found the currency symbol. There should not be more currency symbols. Set
// currSymbol to NULL so that we won't search it again in the later code path.
p = next - 1;
}
else
{
break;
}
}
ch = ++p < strEnd ? *p : '\0';
}
int digCount = 0;
int digEnd = 0;
int maxDigCount = number.Digits.Length - 1;
while (true)
{
if (IsDigit(ch))
{
state |= StateDigits;
if (ch != '0' || (state & StateNonZero) != 0)
{
if (digCount < maxDigCount)
{
number.Digits[digCount++] = (byte)(ch);
if ((ch != '0') || (number.Kind != NumberBufferKind.Integer))
{
digEnd = digCount;
}
}
else if (ch != '0')
{
// For decimal and binary floating-point numbers, we only
// need to store digits up to maxDigCount. However, we still
// need to keep track of whether any additional digits past
// maxDigCount were non-zero, as that can impact rounding
// for an input that falls evenly between two representable
// results.
number.HasNonZeroTail = true;
}
if ((state & StateDecimal) == 0)
{
number.Scale++;
}
state |= StateNonZero;
}
else if ((state & StateDecimal) != 0)
{
number.Scale--;
}
}
else if (((styles & NumberStyles.AllowDecimalPoint) != 0) && ((state & StateDecimal) == 0) && ((next = MatchChars(p, strEnd, decSep)) != null || (parsingCurrency && (state & StateCurrency) == 0) && (next = MatchChars(p, strEnd, info.NumberDecimalSeparator)) != null))
{
state |= StateDecimal;
p = next - 1;
}
else if (((styles & NumberStyles.AllowThousands) != 0) && ((state & StateDigits) != 0) && ((state & StateDecimal) == 0) && ((next = MatchChars(p, strEnd, groupSep)) != null || (parsingCurrency && (state & StateCurrency) == 0) && (next = MatchChars(p, strEnd, info.NumberGroupSeparator)) != null))
{
p = next - 1;
}
else
{
break;
}
ch = ++p < strEnd ? *p : '\0';
}
bool negExp = false;
number.DigitsCount = digEnd;
number.Digits[digEnd] = (byte)('\0');
if ((state & StateDigits) != 0)
{
if ((ch == 'E' || ch == 'e') && ((styles & NumberStyles.AllowExponent) != 0))
{
char* temp = p;
ch = ++p < strEnd ? *p : '\0';
if ((next = MatchChars(p, strEnd, info._positiveSign)) != null)
{
ch = (p = next) < strEnd ? *p : '\0';
}
else if ((next = MatchChars(p, strEnd, info._negativeSign)) != null)
{
ch = (p = next) < strEnd ? *p : '\0';
negExp = true;
}
if (IsDigit(ch))
{
int exp = 0;
do
{
exp = exp * 10 + (ch - '0');
ch = ++p < strEnd ? *p : '\0';
if (exp > 1000)
{
exp = 9999;
while (IsDigit(ch))
{
ch = ++p < strEnd ? *p : '\0';
}
}
} while (IsDigit(ch));
if (negExp)
{
exp = -exp;
}
number.Scale += exp;
}
else
{
p = temp;
ch = p < strEnd ? *p : '\0';
}
}
while (true)
{
if (!IsWhite(ch) || (styles & NumberStyles.AllowTrailingWhite) == 0)
{
if ((styles & NumberStyles.AllowTrailingSign) != 0 && ((state & StateSign) == 0) && ((next = MatchChars(p, strEnd, info.PositiveSign)) != null || (((next = MatchChars(p, strEnd, info.NegativeSign)) != null) && (number.IsNegative = true))))
{
state |= StateSign;
p = next - 1;
}
else if (ch == ')' && ((state & StateParens) != 0))
{
state &= ~StateParens;
}
else if (currSymbol != null && (next = MatchChars(p, strEnd, currSymbol)) != null)
{
currSymbol = null;
p = next - 1;
}
else
{
break;
}
}
ch = ++p < strEnd ? *p : '\0';
}
if ((state & StateParens) == 0)
{
if ((state & StateNonZero) == 0)
{
if (number.Kind != NumberBufferKind.Decimal)
{
number.Scale = 0;
}
if ((number.Kind == NumberBufferKind.Integer) && (state & StateDecimal) == 0)
{
number.IsNegative = false;
}
}
str = p;
return true;
}
}
str = p;
return false;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
internal static ParsingStatus TryParseInt32(ReadOnlySpan<char> value, NumberStyles styles, NumberFormatInfo info, out int result)
{
if ((styles & ~NumberStyles.Integer) == 0)
{
// Optimized path for the common case of anything that's allowed for integer style.
return TryParseInt32IntegerStyle(value, styles, info, out result);
}
if ((styles & NumberStyles.AllowHexSpecifier) != 0)
{
result = 0;
return TryParseUInt32HexNumberStyle(value, styles, out Unsafe.As<int, uint>(ref result));
}
return TryParseInt32Number(value, styles, info, out result);
}
private static unsafe ParsingStatus TryParseInt32Number(ReadOnlySpan<char> value, NumberStyles styles, NumberFormatInfo info, out int result)
{
result = 0;
byte* pDigits = stackalloc byte[Int32NumberBufferLength];
NumberBuffer number = new NumberBuffer(NumberBufferKind.Integer, pDigits, Int32NumberBufferLength);
if (!TryStringToNumber(value, styles, ref number, info))
{
return ParsingStatus.Failed;
}
if (!TryNumberToInt32(ref number, ref result))
{
return ParsingStatus.Overflow;
}
return ParsingStatus.OK;
}
/// <summary>Parses int limited to styles that make up NumberStyles.Integer.</summary>
internal static ParsingStatus TryParseInt32IntegerStyle(ReadOnlySpan<char> value, NumberStyles styles, NumberFormatInfo info, out int result)
{
Debug.Assert((styles & ~NumberStyles.Integer) == 0, "Only handles subsets of Integer format");
if (value.IsEmpty)
goto FalseExit;
int index = 0;
int num = value[0];
// Skip past any whitespace at the beginning.
if ((styles & NumberStyles.AllowLeadingWhite) != 0 && IsWhite(num))
{
do
{
index++;
if ((uint)index >= (uint)value.Length)
goto FalseExit;
num = value[index];
}
while (IsWhite(num));
}
// Parse leading sign.
int sign = 1;
if ((styles & NumberStyles.AllowLeadingSign) != 0)
{
if (info.HasInvariantNumberSigns)
{
if (num == '-')
{
sign = -1;
index++;
if ((uint)index >= (uint)value.Length)
goto FalseExit;
num = value[index];
}
else if (num == '+')
{
index++;
if ((uint)index >= (uint)value.Length)
goto FalseExit;
num = value[index];
}
}
else
{
value = value.Slice(index);
index = 0;
string positiveSign = info.PositiveSign, negativeSign = info.NegativeSign;
if (!string.IsNullOrEmpty(positiveSign) && value.StartsWith(positiveSign))
{
index += positiveSign.Length;
if ((uint)index >= (uint)value.Length)
goto FalseExit;
num = value[index];
}
else if (!string.IsNullOrEmpty(negativeSign) && value.StartsWith(negativeSign))
{
sign = -1;
index += negativeSign.Length;
if ((uint)index >= (uint)value.Length)
goto FalseExit;
num = value[index];
}
}
}
bool overflow = false;
int answer = 0;
if (IsDigit(num))
{
// Skip past leading zeros.
if (num == '0')
{
do
{
index++;
if ((uint)index >= (uint)value.Length)
goto DoneAtEnd;
num = value[index];
} while (num == '0');
if (!IsDigit(num))
goto HasTrailingChars;
}
// Parse most digits, up to the potential for overflow, which can't happen until after 9 digits.
answer = num - '0'; // first digit
index++;
for (int i = 0; i < 8; i++) // next 8 digits can't overflow
{
if ((uint)index >= (uint)value.Length)
goto DoneAtEnd;
num = value[index];
if (!IsDigit(num))
goto HasTrailingChars;
index++;
answer = 10 * answer + num - '0';
}
if ((uint)index >= (uint)value.Length)
goto DoneAtEnd;
num = value[index];
if (!IsDigit(num))
goto HasTrailingChars;
index++;
// Potential overflow now processing the 10th digit.
overflow = answer > int.MaxValue / 10;
answer = answer * 10 + num - '0';
overflow |= (uint)answer > int.MaxValue + (((uint)sign) >> 31);
if ((uint)index >= (uint)value.Length)
goto DoneAtEndButPotentialOverflow;
// At this point, we're either overflowing or hitting a formatting error.
// Format errors take precedence for compatibility.
num = value[index];
while (IsDigit(num))
{
overflow = true;
index++;
if ((uint)index >= (uint)value.Length)
goto OverflowExit;
num = value[index];
}
goto HasTrailingChars;
}
goto FalseExit;
DoneAtEndButPotentialOverflow:
if (overflow)
{
goto OverflowExit;
}
DoneAtEnd:
result = answer * sign;
ParsingStatus status = ParsingStatus.OK;
Exit:
return status;
FalseExit: // parsing failed
result = 0;
status = ParsingStatus.Failed;
goto Exit;
OverflowExit:
result = 0;
status = ParsingStatus.Overflow;
goto Exit;
HasTrailingChars: // we've successfully parsed, but there are still remaining characters in the span
// Skip past trailing whitespace, then past trailing zeros, and if anything else remains, fail.
if (IsWhite(num))
{
if ((styles & NumberStyles.AllowTrailingWhite) == 0)
goto FalseExit;
for (index++; index < value.Length; index++)
{
if (!IsWhite(value[index]))
break;
}
if ((uint)index >= (uint)value.Length)
goto DoneAtEndButPotentialOverflow;
}
if (!TrailingZeros(value, index))
goto FalseExit;
goto DoneAtEndButPotentialOverflow;
}
/// <summary>Parses long inputs limited to styles that make up NumberStyles.Integer.</summary>
internal static ParsingStatus TryParseInt64IntegerStyle(ReadOnlySpan<char> value, NumberStyles styles, NumberFormatInfo info, out long result)
{
Debug.Assert((styles & ~NumberStyles.Integer) == 0, "Only handles subsets of Integer format");
if (value.IsEmpty)
goto FalseExit;
int index = 0;
int num = value[0];
// Skip past any whitespace at the beginning.
if ((styles & NumberStyles.AllowLeadingWhite) != 0 && IsWhite(num))
{
do
{
index++;
if ((uint)index >= (uint)value.Length)
goto FalseExit;
num = value[index];
}
while (IsWhite(num));
}
// Parse leading sign.
int sign = 1;
if ((styles & NumberStyles.AllowLeadingSign) != 0)
{
if (info.HasInvariantNumberSigns)
{
if (num == '-')
{
sign = -1;
index++;
if ((uint)index >= (uint)value.Length)
goto FalseExit;
num = value[index];
}
else if (num == '+')
{
index++;
if ((uint)index >= (uint)value.Length)
goto FalseExit;
num = value[index];
}
}
else
{
value = value.Slice(index);
index = 0;
string positiveSign = info.PositiveSign, negativeSign = info.NegativeSign;
if (!string.IsNullOrEmpty(positiveSign) && value.StartsWith(positiveSign))
{
index += positiveSign.Length;
if ((uint)index >= (uint)value.Length)
goto FalseExit;
num = value[index];
}
else if (!string.IsNullOrEmpty(negativeSign) && value.StartsWith(negativeSign))
{
sign = -1;
index += negativeSign.Length;
if ((uint)index >= (uint)value.Length)
goto FalseExit;
num = value[index];
}
}
}
bool overflow = false;
long answer = 0;
if (IsDigit(num))
{
// Skip past leading zeros.
if (num == '0')
{
do
{
index++;
if ((uint)index >= (uint)value.Length)
goto DoneAtEnd;
num = value[index];
} while (num == '0');
if (!IsDigit(num))
goto HasTrailingChars;
}
// Parse most digits, up to the potential for overflow, which can't happen until after 18 digits.
answer = num - '0'; // first digit
index++;
for (int i = 0; i < 17; i++) // next 17 digits can't overflow
{
if ((uint)index >= (uint)value.Length)
goto DoneAtEnd;
num = value[index];
if (!IsDigit(num))
goto HasTrailingChars;
index++;
answer = 10 * answer + num - '0';
}
if ((uint)index >= (uint)value.Length)
goto DoneAtEnd;
num = value[index];
if (!IsDigit(num))
goto HasTrailingChars;
index++;
// Potential overflow now processing the 19th digit.
overflow = answer > long.MaxValue / 10;
answer = answer * 10 + num - '0';
overflow |= (ulong)answer > (ulong)long.MaxValue + (((uint)sign) >> 31);
if ((uint)index >= (uint)value.Length)
goto DoneAtEndButPotentialOverflow;
// At this point, we're either overflowing or hitting a formatting error.
// Format errors take precedence for compatibility.
num = value[index];
while (IsDigit(num))
{
overflow = true;
index++;
if ((uint)index >= (uint)value.Length)
goto OverflowExit;
num = value[index];
}
goto HasTrailingChars;
}
goto FalseExit;
DoneAtEndButPotentialOverflow:
if (overflow)
{
goto OverflowExit;
}
DoneAtEnd:
result = answer * sign;
ParsingStatus status = ParsingStatus.OK;
Exit:
return status;
FalseExit: // parsing failed
result = 0;
status = ParsingStatus.Failed;
goto Exit;
OverflowExit:
result = 0;
status = ParsingStatus.Overflow;
goto Exit;
HasTrailingChars: // we've successfully parsed, but there are still remaining characters in the span
// Skip past trailing whitespace, then past trailing zeros, and if anything else remains, fail.
if (IsWhite(num))
{
if ((styles & NumberStyles.AllowTrailingWhite) == 0)
goto FalseExit;
for (index++; index < value.Length; index++)
{
if (!IsWhite(value[index]))
break;
}
if ((uint)index >= (uint)value.Length)
goto DoneAtEndButPotentialOverflow;
}
if (!TrailingZeros(value, index))
goto FalseExit;
goto DoneAtEndButPotentialOverflow;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
internal static ParsingStatus TryParseInt64(ReadOnlySpan<char> value, NumberStyles styles, NumberFormatInfo info, out long result)
{
if ((styles & ~NumberStyles.Integer) == 0)
{
// Optimized path for the common case of anything that's allowed for integer style.
return TryParseInt64IntegerStyle(value, styles, info, out result);
}
if ((styles & NumberStyles.AllowHexSpecifier) != 0)
{
result = 0;
return TryParseUInt64HexNumberStyle(value, styles, out Unsafe.As<long, ulong>(ref result));
}
return TryParseInt64Number(value, styles, info, out result);
}
private static unsafe ParsingStatus TryParseInt64Number(ReadOnlySpan<char> value, NumberStyles styles, NumberFormatInfo info, out long result)
{
result = 0;
byte* pDigits = stackalloc byte[Int64NumberBufferLength];
NumberBuffer number = new NumberBuffer(NumberBufferKind.Integer, pDigits, Int64NumberBufferLength);
if (!TryStringToNumber(value, styles, ref number, info))
{
return ParsingStatus.Failed;
}
if (!TryNumberToInt64(ref number, ref result))
{
return ParsingStatus.Overflow;
}
return ParsingStatus.OK;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
internal static ParsingStatus TryParseUInt32(ReadOnlySpan<char> value, NumberStyles styles, NumberFormatInfo info, out uint result)
{
if ((styles & ~NumberStyles.Integer) == 0)
{
// Optimized path for the common case of anything that's allowed for integer style.
return TryParseUInt32IntegerStyle(value, styles, info, out result);
}
if ((styles & NumberStyles.AllowHexSpecifier) != 0)
{
return TryParseUInt32HexNumberStyle(value, styles, out result);
}
return TryParseUInt32Number(value, styles, info, out result);
}
private static unsafe ParsingStatus TryParseUInt32Number(ReadOnlySpan<char> value, NumberStyles styles, NumberFormatInfo info, out uint result)
{
result = 0;
byte* pDigits = stackalloc byte[UInt32NumberBufferLength];
NumberBuffer number = new NumberBuffer(NumberBufferKind.Integer, pDigits, UInt32NumberBufferLength);
if (!TryStringToNumber(value, styles, ref number, info))
{
return ParsingStatus.Failed;
}
if (!TryNumberToUInt32(ref number, ref result))
{
return ParsingStatus.Overflow;
}
return ParsingStatus.OK;
}
/// <summary>Parses uint limited to styles that make up NumberStyles.Integer.</summary>
internal static ParsingStatus TryParseUInt32IntegerStyle(ReadOnlySpan<char> value, NumberStyles styles, NumberFormatInfo info, out uint result)
{
Debug.Assert((styles & ~NumberStyles.Integer) == 0, "Only handles subsets of Integer format");
if (value.IsEmpty)
goto FalseExit;
int index = 0;
int num = value[0];
// Skip past any whitespace at the beginning.
if ((styles & NumberStyles.AllowLeadingWhite) != 0 && IsWhite(num))
{
do
{
index++;
if ((uint)index >= (uint)value.Length)
goto FalseExit;
num = value[index];
}
while (IsWhite(num));
}
// Parse leading sign.
bool overflow = false;
if ((styles & NumberStyles.AllowLeadingSign) != 0)
{
if (info.HasInvariantNumberSigns)
{
if (num == '+')
{
index++;
if ((uint)index >= (uint)value.Length)
goto FalseExit;
num = value[index];
}
else if (num == '-')
{
overflow = true;
index++;
if ((uint)index >= (uint)value.Length)
goto FalseExit;
num = value[index];
}
}
else
{
value = value.Slice(index);
index = 0;
string positiveSign = info.PositiveSign, negativeSign = info.NegativeSign;
if (!string.IsNullOrEmpty(positiveSign) && value.StartsWith(positiveSign))
{
index += positiveSign.Length;
if ((uint)index >= (uint)value.Length)
goto FalseExit;
num = value[index];
}
else if (!string.IsNullOrEmpty(negativeSign) && value.StartsWith(negativeSign))
{
overflow = true;
index += negativeSign.Length;
if ((uint)index >= (uint)value.Length)
goto FalseExit;