We propose to implement a DSL and asociated API for expressing job selectors in a way similar to what we have for execution policies. This will significantly improve the expressiveness of job selectors, without having to resort to scripted job selectors for complex selection functions.

This DSL would include a number of predicates and operators:

• boolean predicates: and, or, xor, not
• comparison operators for Comparable metadata values: ==, !=, <, <=, >, >=, between (including or excluding upper and lower bounds)
• contains, one of, regex matching
• any other predicate that we migth find useful or convenient