Function xrust::evaluate::evaluate

pub fn evaluate<'a>(
    dc: &'a DynamicContext<'a>, 
    ctxt: Option<Sequence<'a>>, 
    posn: Option<usize>, 
    c: &'a Vec<Constructor<'a>>
) -> Result<Sequence<'a>, Error>

Evaluate a sequence constructor, given a dynamic context.

The dynamic context consists of the supplied context, as well as the context item. The context item, which is optional, consists of a Sequence and an index to an item. If the context sequence is supplied, then the index (posn) must also be supplied and be a valid index for the sequence.