bound-fn*
- (bound-fn* f)
Returns a function, which will install the same bindings in effect as in the thread at the time bound-fn* was called and then call f with any given arguments. This may be used to define a helper function which runs on a different thread, but needs the same bindings in place.
© Rich Hickey. All rights reserved. Eclipse Public License 1.0
2 Examples
(def ^:dynamic *some-var* nil) (defn f [] (println *some-var*)) ;; run f without a new binding user=> (f) nil nil ;; run f with a new binding user=> (binding [*some-var* "hello"] (f)) hello nil ;; run f in a thread with a new binding user=> (binding [*some-var* "goodbye"] (.start (Thread. f))) nil nil ;; run a bound f in a thread with a new binding user=> (binding [*some-var* "goodbye"] (.start (Thread. (bound-fn* f)))) goodbye nil
;; Capture thread local bindings so the lazy sequence can realize outside ;; the binding block (def ^:dynamic *a* nil) (binding [*a* 1] (map #(+ % *a*) (range 10))) ;; NullPointerException clojure.lang.Numbers.ops (Numbers.java:1013) (binding [*a* 1] (map (bound-fn* #(+ % *a*)) (range 10))) ;; (1 2 3 4 5 6 7 8 9 10)