public ParseResult <Period> Parse(string text)
{
if (text is null)
{
return(ParseResult <Period> .ArgumentNull("text"));
}
if (text.Length == 0)
{
return(ParseResult <Period> .ValueStringEmpty);
}
ValueCursor valueCursor = new ValueCursor(text);
valueCursor.MoveNext();
if (valueCursor.Current != 'P')
{
return(ParseResult <Period> .MismatchedCharacter(valueCursor, 'P'));
}
bool inDate = true;
PeriodBuilder builder = new PeriodBuilder();
PeriodUnits unitsSoFar = 0;
while (valueCursor.MoveNext())
{
if (inDate && valueCursor.Current == 'T')
{
inDate = false;
continue;
}
var failure = valueCursor.ParseInt64 <Period>(out long unitValue);
if (failure != null)
{
return(failure);
}
if (valueCursor.Length == valueCursor.Index)
{
return(ParseResult <Period> .EndOfString(valueCursor));
}
// Various failure cases:
// - Repeated unit (e.g. P1M2M)
// - Time unit is in date part (e.g. P5M)
// - Date unit is in time part (e.g. PT1D)
// - Unit is in incorrect order (e.g. P5D1Y)
// - Unit is invalid (e.g. P5J)
// - Unit is missing (e.g. P5)
PeriodUnits unit;
switch (valueCursor.Current)
{
case 'Y': unit = PeriodUnits.Years; break;
case 'M': unit = inDate ? PeriodUnits.Months : PeriodUnits.Minutes; break;
case 'W': unit = PeriodUnits.Weeks; break;
case 'D': unit = PeriodUnits.Days; break;
case 'H': unit = PeriodUnits.Hours; break;
case 'S': unit = PeriodUnits.Seconds; break;
case 's': unit = PeriodUnits.Milliseconds; break;
case 't': unit = PeriodUnits.Ticks; break;
case 'n': unit = PeriodUnits.Nanoseconds; break;
default: return(InvalidUnit(valueCursor, valueCursor.Current));
}
if ((unit & unitsSoFar) != 0)
{
return(RepeatedUnit(valueCursor, valueCursor.Current));
}
// This handles putting months before years, for example. Less significant units
// have higher integer representations.
if (unit < unitsSoFar)
{
return(MisplacedUnit(valueCursor, valueCursor.Current));
}
// The result of checking "there aren't any time units in this unit" should be
// equal to "we're still in the date part".
if ((unit & PeriodUnits.AllTimeUnits) == 0 != inDate)
{
return(MisplacedUnit(valueCursor, valueCursor.Current));
}
builder[unit] = unitValue;
unitsSoFar |= unit;
}
return(ParseResult <Period> .ForValue(builder.Build()));
}
// TODO(misc): Tidy this up a *lot*.
public ParseResult <Period> Parse(string text)
{
if (text is null)
{
return(ParseResult <Period> .ArgumentNull("text"));
}
if (text.Length == 0)
{
return(ParseResult <Period> .ValueStringEmpty);
}
ValueCursor valueCursor = new ValueCursor(text);
valueCursor.MoveNext();
if (valueCursor.Current != 'P')
{
return(ParseResult <Period> .MismatchedCharacter(valueCursor, 'P'));
}
bool inDate = true;
PeriodBuilder builder = new PeriodBuilder();
PeriodUnits unitsSoFar = 0;
while (valueCursor.MoveNext())
{
if (inDate && valueCursor.Current == 'T')
{
inDate = false;
continue;
}
bool negative = valueCursor.Current == '-';
var failure = valueCursor.ParseInt64 <Period>(out long unitValue);
if (failure != null)
{
return(failure);
}
if (valueCursor.Length == valueCursor.Index)
{
return(ParseResult <Period> .EndOfString(valueCursor));
}
// Various failure cases:
// - Repeated unit (e.g. P1M2M)
// - Time unit is in date part (e.g. P5M)
// - Date unit is in time part (e.g. PT1D)
// - Unit is in incorrect order (e.g. P5D1Y)
// - Unit is invalid (e.g. P5J)
// - Unit is missing (e.g. P5)
PeriodUnits unit;
switch (valueCursor.Current)
{
case 'Y': unit = PeriodUnits.Years; break;
case 'M': unit = inDate ? PeriodUnits.Months : PeriodUnits.Minutes; break;
case 'W': unit = PeriodUnits.Weeks; break;
case 'D': unit = PeriodUnits.Days; break;
case 'H': unit = PeriodUnits.Hours; break;
case 'S': unit = PeriodUnits.Seconds; break;
case ',':
case '.': unit = PeriodUnits.Nanoseconds; break; // Special handling below
default: return(InvalidUnit(valueCursor, valueCursor.Current));
}
if ((unit & unitsSoFar) != 0)
{
return(RepeatedUnit(valueCursor, valueCursor.Current));
}
// This handles putting months before years, for example. Less significant units
// have higher integer representations.
if (unit < unitsSoFar)
{
return(MisplacedUnit(valueCursor, valueCursor.Current));
}
// The result of checking "there aren't any time units in this unit" should be
// equal to "we're still in the date part".
if ((unit & PeriodUnits.AllTimeUnits) == 0 != inDate)
{
return(MisplacedUnit(valueCursor, valueCursor.Current));
}
// Seen a . or , which need special handling.
if (unit == PeriodUnits.Nanoseconds)
{
// Check for already having seen seconds, e.g. PT5S0.5
if ((unitsSoFar & PeriodUnits.Seconds) != 0)
{
return(MisplacedUnit(valueCursor, valueCursor.Current));
}
builder.Seconds = unitValue;
if (!valueCursor.MoveNext())
{
return(ParseResult <Period> .MissingNumber(valueCursor));
}
// Can cope with at most 999999999 nanoseconds
if (!valueCursor.ParseFraction(9, 9, out int totalNanoseconds, 1))
{
return(ParseResult <Period> .MissingNumber(valueCursor));
}
// Use whether or not the seconds value was negative (even if 0)
// as the indication of whether this value is negative.
if (negative)
{
totalNanoseconds = -totalNanoseconds;
}
builder.Milliseconds = (totalNanoseconds / NanosecondsPerMillisecond) % MillisecondsPerSecond;
builder.Ticks = (totalNanoseconds / NanosecondsPerTick) % TicksPerMillisecond;
builder.Nanoseconds = totalNanoseconds % NanosecondsPerTick;
if (valueCursor.Current != 'S')
{
return(ParseResult <Period> .MismatchedCharacter(valueCursor, 'S'));
}
if (valueCursor.MoveNext())
{
return(ParseResult <Period> .ExpectedEndOfString(valueCursor));
}
return(ParseResult <Period> .ForValue(builder.Build()));
}
builder[unit] = unitValue;
unitsSoFar |= unit;
}
if (unitsSoFar == 0)
{
return(ParseResult <Period> .ForInvalidValue(valueCursor, TextErrorMessages.EmptyPeriod));
}
return(ParseResult <Period> .ForValue(builder.Build()));
}
/// <summary>
/// Parses digits at the current point in the string as a signed 64-bit integer value.
/// Currently this method only supports cultures whose negative sign is "-" (and
/// using ASCII digits).
/// </summary>
/// <param name="result">The result integer value. The value of this is not guaranteed
/// to be anything specific if the return value is non-null.</param>
/// <returns>null if the digits were parsed, or the appropriate parse failure</returns>
internal ParseResult <T> ParseInt64 <T>(out long result)
{
unchecked
{
result = 0L;
int startIndex = Index;
bool negative = Current == '-';
if (negative)
{
if (!MoveNext())
{
Move(startIndex);
return(ParseResult <T> .EndOfString(this));
}
}
int count = 0;
int digit;
while (result < 922337203685477580 && (digit = GetDigit()) != -1)
{
result = result * 10 + digit;
count++;
if (!MoveNext())
{
break;
}
}
if (count == 0)
{
Move(startIndex);
return(ParseResult <T> .MissingNumber(this));
}
if (result >= 922337203685477580 && (digit = GetDigit()) != -1)
{
if (result > 922337203685477580)
{
return(BuildNumberOutOfRangeResult <T>(startIndex));
}
if (negative && digit == 8)
{
MoveNext();
result = long.MinValue;
return(null);
}
if (digit > 7)
{
return(BuildNumberOutOfRangeResult <T>(startIndex));
}
// We know we can cope with this digit...
result = result * 10 + digit;
MoveNext();
if (GetDigit() != -1)
{
// Too many digits. Die.
return(BuildNumberOutOfRangeResult <T>(startIndex));
}
}
if (negative)
{
result = -result;
}
return(null);
}
}
