tryParseRadix static method
Parses source in a given radix between 2 and 36.
Returns an Int64 with the numerical value of source.
If the numerical value of source does not fit
in a signed 64 bit integer,
the numerical value is truncated to the lowest 64 bits
of the value's binary representation,
interpreted as a 64-bit two's complement integer.
The source string must contain a sequence of base-radix
digits (using letters from a to z as digits with values 10 through
25 for radixes above 10), possibly prefixed by a - sign.
Returns null if the input is not recognized as a valid
integer numeral.
Implementation
static Int64? tryParseRadix(String source, int radix) =>
_parseRadix(source, u.validateRadix(radix), false);