pub(crate) fn match_var_format(v: &str) -> Option<ReadStatVarFormatClass>Expand description
Classifies a SAS format string into a ReadStatVarFormatClass.
Returns Some(class) for recognized date/time/datetime formats, or None
for numeric/character formats that don’t represent temporal data.
Matching is case-insensitive and handles both numeric widths (DATE9)
and letter-width suffixes (DATEW).