Function piece_up_to_next 

pub fn piece_up_to_next(
    model: &mut NamedModel,
    namer: &Namer,
    tool: SolidId,
    stops: &[SolidId],
    (start, end): (&str, &str),
    params: RemeshParams,
) -> GeopResult<Reach<SolidId>>

The first piece of tool its face start reaches outside stops — up to the next face of any of them — as a solid of its own, named namer’s root, stops left as they are: what a new body going up to the next face is. Reach::RunsOn, as boolean_up_to_next does, if nothing stops the tool before its face end.

The tool is cut by a copy of the solids it stops at, so that only the copy is imprinted and consumed.