[local-time-devel] arbitrary precision for fraction of a second

[Daniel Herring]

On Wed, 14 Jul 2010, david thompson wrote:

> My understanding is that the ISO 8601 spec permits an arbitrary number
> of digits following the decimal point when a decimal fraction of an
> hour, minute, or second is specified.
>
> This works fine:
>>  (LOCAL-TIME:PARSE-TIMESTRING "2010-07-12T16:07:08.123742200")
> @2010-07-12T09:07:08.123742-07:00
>
> This doesn't:
>> (LOCAL-TIME:PARSE-TIMESTRING "2010-07-12T16:07:08.1237422004")
>
> Is the constraint on the number of digits LOCAL-TIME permits following
> the decimal character specified in the LOCAL-TIME documentation?

PARSE-TIMESTRING is layered on top of %SPLIT-TIMESTRING, which has the 
following docstring.
"Based on http://www.ietf.org/rfc/rfc3339.txt including the function names 
used. Returns (values year month day hour minute second nsec offset-hour 
offset-minute). On parsing failure, signals INVALID-TIMESTRING if 
FAIL-ON-ERROR is NIL, otherwise returns NIL."

Does that RFC make any restrictions on the precision?

Anyway, the issue you are hitting is that TIME-SECOND within 
%SPLIT-TIMESTRING is reading 1237422004 as an integer and failing to 
convert it into an integer number of nanoseconds.  Instead of silently 
truncating the 4, the function signals an error.

Later,
Daniel