public ASTNode Parse(Token sourceToken, ParseContext context)
{
if (!context.Check(TokenType.Semicolon))
{
return(new ReturnNode(sourceToken, context.ParseExpression()));
}
else
{
return(new ReturnNode(sourceToken, null));
}
}
protected bool ParseDateTime(string s, DateTimePart part)
{
ParseContext context = new ParseContext(s);
bool bDatePart = ( part & DateTimePart.Date ) != 0;
bool bTimePart = ( part & DateTimePart.Time ) != 0;
int year = 0, month = 0, day = 0;
int hour = 0, minute = 0;
double second = 0;
eTZ = ETZ.Missing;
offsetTZ = 0;
if ( bDatePart )
{
// parse date
bool bNegative = context.CheckAndAdvance( '-' );
if ( (part & DateTimePart.Year ) != 0 )
{
int digits = 0;
int temp = 0;
while ( context.ReadDigitAndAdvance( ref temp, 1, 9 ) )
{
year = year * 10 + temp;
digits += 1;
temp = 0;
if (digits >= 8) // overflow
return false;
}
if ( digits < 4 ) // invalid.
return false;
if ( digits > 4 && year < 10000 )
return false;
if (bNegative)
year = -year;
}
if ( (part & ( DateTimePart.Month | DateTimePart.Day )) != 0 )
{
if ( !context.CheckAndAdvance( '-' ) ) return false;
if ( ( part & DateTimePart.Month ) != 0 )
{
if ( !context.ReadDigitAndAdvance( ref month, 10, 1 ) ) return false;
if ( !context.ReadDigitAndAdvance( ref month, 1, month < 10 ? 9 : 2 ) ) return false;
if ( month == 0 ) return false;
}
if ( ( part & DateTimePart.Day ) != 0 )
{
if ( !context.CheckAndAdvance( '-') ) return false;
int maxFirstDigit = month != 2 ? 3 : 2;
// complicate things by making them complicated.
if ( !context.ReadDigitAndAdvance( ref day, 10, maxFirstDigit ) ) return false;
if ( !context.ReadDigitAndAdvance( ref day, 1, 9 ) ) return false;
if ( day == 0 || day > 31 ) return false;
if ( ( part & DateTimePart.Month ) != 0 )
{
bool b1 = month <= 7;
bool b2 = ( month & 1 ) == 0;
// month 1, 3, 5, 7, 8, 10, 12
if ( b1 == b2 && day > 30 )
return false;
// february.
if ( month == 2 && day > 29 )
return false;
// leap years.
if ( month == 2 && ( part & DateTimePart.Year ) != 0 &&
( year % 4 != 0 || year % 100 == 0 ) && year % 400 != 0 &&
day > 28 )
return false;
}
}
}
if ( bTimePart )
{
// a 'T' must follow
if ( !context.CheckAndAdvance( 'T') ) return false;
}
}
if ( bTimePart )
{
// check format here
// hour from 0 to 2
if ( !context.ReadDigitAndAdvance( ref hour, 10, 2 ) ) return false;
if ( !context.ReadDigitAndAdvance( ref hour, 1, hour < 20 ? 9 : 4 ) ) return false;
if ( !context.CheckAndAdvance( ':' ) ) return false;
int maxFirstDigit = hour == 24 ? 0 : 5;
int maxSecondDigit = hour == 24 ? 0 : 9;
if ( !context.ReadDigitAndAdvance( ref minute, 10, maxFirstDigit ) ) return false;
if ( !context.ReadDigitAndAdvance( ref minute, 1, maxSecondDigit ) ) return false;
if ( !context.CheckAndAdvance( ':' ) ) return false;
int secondInt = 0;
if ( !context.ReadDigitAndAdvance( ref secondInt, 10, maxFirstDigit ) ) return false;
if ( !context.ReadDigitAndAdvance( ref secondInt, 1, maxSecondDigit ) ) return false;
second = secondInt;
if ( context.CheckAndAdvance( '.' ) )
{
// fraction. do whatever seems fit.
int val = 0;
int digits = 0;
while ( context.ReadDigitAndAdvance( ref val, 1, 9) )
{
val *= 10;
digits += 1;
if ( digits >= 8 ) // precision loss - ignore
break;
}
if ( digits == 0 )
return false;
second += val * Math.Pow( 10.0, -digits - 1 );
// skip any further digits.
while ( context.ReadDigitAndAdvance( ref val, 0, 9) )
;
}
}
// timezone
if ( context.CheckAndAdvance('Z') )
{
// timezone specified, it is UTC.
eTZ = ETZ.UTC;
offsetTZ = 0;
}
else if ( context.Check('+') || context.Check('-' ) )
{
// timezone offset, in hour:minute format
bool bNegative = context.Check('-');
context.Advance();
// do not check the hour part, for those who are obscure.
int temp = 0;
if ( !context.ReadDigitAndAdvance( ref temp, 600, 9 ) ) return false;
if ( !context.ReadDigitAndAdvance( ref temp, 60, 9 ) ) return false;
if ( !context.CheckAndAdvance( ':' ) ) return false;
if ( !context.ReadDigitAndAdvance( ref temp, 10, 5 ) ) return false;
if ( !context.ReadDigitAndAdvance( ref temp, 1, 9 ) ) return false;
eTZ = ETZ.Offset;
offsetTZ = bNegative ? -temp : temp;
}
if ( context.IsValid() )
return false;
// C# specific
if (year <= 0) year = 1;
if (month == 0) month = 1;
bool badjust = false;
if (hour == 24)
{
hour = 0;
badjust = true;
}
if (day == 0) day = 1;
try {
myValue = new System.DateTime(year, month, day, hour, minute, (int)second,
(int)(second * 1000) % 1000);
if (badjust)
myValue.AddDays(1);
}
catch
{
return false;
}
return true;
}
bool ParseDateTime(string s, DateTimePart part)
{
ParseContext context = new ParseContext(s);
bool bDatePart = (part & DateTimePart.Date) != 0;
bool bTimePart = (part & DateTimePart.Time) != 0;
int year = 0, month = 0, day = 0;
int hour = 0, minute = 0;
double second = 0;
timezone = NoTimezone;
if (bDatePart)
{
// parse date
bool bNegative = context.CheckAndAdvance('-');
if ((part & DateTimePart.Year) != 0)
{
int digits = 0;
int temp = 0;
while (context.ReadDigitAndAdvance(ref temp, 1, 9))
{
year = year * 10 + temp;
digits += 1;
temp = 0;
if (digits >= 8) // overflow
{
return(false);
}
}
if (digits < 4) // invalid.
{
return(false);
}
if (digits > 4 && year < 10000)
{
return(false);
}
if (bNegative)
{
year = -year;
}
}
if ((part & (DateTimePart.Month | DateTimePart.Day)) != 0)
{
if (!context.CheckAndAdvance('-'))
{
return(false);
}
if ((part & DateTimePart.Month) != 0)
{
if (!context.ReadDigitAndAdvance(ref month, 10, 1))
{
return(false);
}
if (!context.ReadDigitAndAdvance(ref month, 1, month < 10 ? 9 : 2))
{
return(false);
}
if (month == 0)
{
return(false);
}
}
if ((part & DateTimePart.Day) != 0)
{
if (!context.CheckAndAdvance('-'))
{
return(false);
}
int maxFirstDigit = month != 2 ? 3 : 2;
// complicate things by making them complicated.
if (!context.ReadDigitAndAdvance(ref day, 10, maxFirstDigit))
{
return(false);
}
if (!context.ReadDigitAndAdvance(ref day, 1, 9))
{
return(false);
}
if (day == 0 || day > 31)
{
return(false);
}
if ((part & DateTimePart.Month) != 0)
{
bool b1 = month <= 7;
bool b2 = (month & 1) == 0;
// month 1, 3, 5, 7, 8, 10, 12
if (b1 == b2 && day > 30)
{
return(false);
}
// february.
if (month == 2 && day > 29)
{
return(false);
}
// leap years.
if (month == 2 && (part & DateTimePart.Year) != 0 &&
(year % 4 != 0 || year % 100 == 0) && year % 400 != 0 &&
day > 28)
{
return(false);
}
}
}
}
if (bTimePart)
{
// a 'T' must follow
if (!context.CheckAndAdvance('T'))
{
return(false);
}
}
}
if (bTimePart)
{
// check format here
// hour from 0 to 2
if (!context.ReadDigitAndAdvance(ref hour, 10, 2))
{
return(false);
}
if (!context.ReadDigitAndAdvance(ref hour, 1, hour < 20 ? 9 : 4))
{
return(false);
}
if (!context.CheckAndAdvance(':'))
{
return(false);
}
int maxFirstDigit = hour == 24 ? 0 : 5;
int maxSecondDigit = hour == 24 ? 0 : 9;
if (!context.ReadDigitAndAdvance(ref minute, 10, maxFirstDigit))
{
return(false);
}
if (!context.ReadDigitAndAdvance(ref minute, 1, maxSecondDigit))
{
return(false);
}
if (!context.CheckAndAdvance(':'))
{
return(false);
}
int secondInt = 0;
if (!context.ReadDigitAndAdvance(ref secondInt, 10, maxFirstDigit))
{
return(false);
}
if (!context.ReadDigitAndAdvance(ref secondInt, 1, maxSecondDigit))
{
return(false);
}
second = secondInt;
if (context.CheckAndAdvance('.'))
{
// fraction. do whatever seems fit.
int val = 0;
int digits = 0;
while (context.ReadDigitAndAdvance(ref val, 1, 9))
{
val *= 10;
digits += 1;
if (digits >= 8) // precision loss - ignore
{
break;
}
}
if (digits == 0)
{
return(false);
}
second += val * System.Math.Pow(10.0, -digits - 1);
// skip any further digits.
while (context.ReadDigitAndAdvance(ref val, 0, 9))
{
;
}
}
}
// timezone
if (context.CheckAndAdvance('Z'))
{
// timezone specified, it is UTC.
timezone = 0;
}
else if (context.Check('+') || context.Check('-'))
{
// timezone offset, in hour:minute format
bool bNegative = context.Check('-');
context.Advance();
// do not check the hour part, for those who are obscure.
int temp = 0;
if (!context.ReadDigitAndAdvance(ref temp, 600, 9))
{
return(false);
}
if (!context.ReadDigitAndAdvance(ref temp, 60, 9))
{
return(false);
}
if (!context.CheckAndAdvance(':'))
{
return(false);
}
if (!context.ReadDigitAndAdvance(ref temp, 10, 5))
{
return(false);
}
if (!context.ReadDigitAndAdvance(ref temp, 1, 9))
{
return(false);
}
timezone = (short)(bNegative ? -temp : temp);
}
if (context.IsValid())
{
return(false);
}
// C# specific
if (year <= 0)
{
year = 1;
}
if (month == 0)
{
month = 1;
}
bool badjust = false;
if (hour == 24)
{
hour = 0;
badjust = true;
}
if (day == 0)
{
day = 1;
}
if ((part & DateTimePart.Year) == 0 && month == 2 && day == 29)
{
year = 4;
}
try
{
myValue = new System.DateTime(year, month, day, hour, minute, (int)second,
(int)(second * 1000) % 1000);
if (badjust)
{
myValue.AddDays(1);
}
}
catch
{
return(false);
}
return(true);
}
