prefer-method
- (prefer-method multifn dispatch-val-x dispatch-val-y)
Causes the multimethod to prefer matches of dispatch-val-x over dispatch-val-y when there is a conflict
© Rich Hickey. All rights reserved. Eclipse Public License 1.0
1 Example
(def m {:os ::osx}) (defmulti ex :os) (defmethod ex ::unix [_] "unix") (derive ::osx ::unix) (ex m) ;;=> "unix" (defmethod ex ::bsd [_] "bsd") (derive ::osx ::bsd) ;; which one to choose ::unix or ::bsd ?? -> Conflict!!! (ex m) ;;=> IllegalArgumentException Multiple methods in multimethod 'ex' match... (prefer-method ex ::unix ::bsd) (ex m) ;;=> "unix"