Predicate dispatch
| Polymorphism |
|---|
| Ad hoc polymorphism |
| Parametric polymorphism |
| Subtyping |
In computer programming, predicate dispatch is a generalisation of multiple dispatch ("multimethods") that allows the method to call to be selected at runtime based on arbitrary decidable logical predicates and/or pattern matching attached to a method declaration.[1][2]
Raku supports predicate dispatch using "where" clauses that can execute arbitrary code against any function or method parameter.[3]
Julia has a package for it with PatternDispatch.jl but otherwise natively supports multiple dispatch.
Experimental implementations have been created for Common LISP,[4][5] and for Java (JPred[2]).
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
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- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value). (To view documents see Help:FTP)
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
External links
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