pub fn parse_marker(value: &OsStr) -> Option<StartMarker>Expand description
What:
Take a marker value apart.
Option<StartMarker> is “the marker,
or nothing when the text is not one”.
Why:
A variable some other program set to other text must not stop a wrapper,
so anything that is not exactly three
fields of the right kinds is no marker.
In TS you’d write (pseudocode):
function parseMarker(value: string): StartMarker | undefined;