Predicate dispatch
In computer programming, predicate dispatch is a method of runtime polymorphism that generalises multiple dispatch ("multi methods"),that allows method calls to be selected at runtime based on arbitrary decidable logical predicates and/or pattern matching attached to a method declaration.[1]
Julia has a package for it with PatternDispatch.jl but otherwise natively supports multiple dispatch.
Experimental implementations have been created for Common LISP,[2][3] and for Java (JPred[1]).
It allows open extension of previously declared methods at a fine-grained level, but multiple extensions with identical or overlapping predicates created by different developers may interfere with each other in unanticipated ways. In this respect it is similar to aspect-oriented programming.
References
- 1 2 Millstein, T.; Frost, C.; Ryder, J.; Warth, A. (2009). "Expressive and modular predicate dispatch for Java". ACM Transactions on Programming Languages and Systems. 31 (2): 1. doi:10.1145/1462166.1462168.
- ↑ "Predicate Dispatching in Common Lisp Object System" (PDF).
- ↑ "pcostanza/filtered-functions". GitHub. Retrieved 2016-04-07.