match: simplify brittle predicate construction In match.__init__(), we create the matchfn predicate by and-ing together the individual predicates for includes, excludes (negated) and patterns. Instead of the current set of nested if/else blocks, we can simplify by adding the predicates to a list and defining the overall predicate in a generic way based on the components. We can still optimize it for the 0-length and 1-length cases. This way, there is no combinatorial explosion to deal with if new component predicates are added, and there is less risk of getting the overall predicate wrong.