fn determine_format_w_datetimefield(
    toks: VecDeque<TimeStrToken>,
    leading_time_precision: Option<DateTimeField>
) -> Result<Option<TimePartFormat>, String>
Expand description

Determines the format of the interval part (uses None to identify an indeterminant/ambiguous format). This is necessary because the interval string format is not LL(1); we instead parse as few tokens as possible to generate the string’s semantics.

Note that toks should not contain space