clojure.core/add-tap

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Type: function Added: Clojure 1.10 Examples: 2 Runnable: 0

([f])

adds f, a fn of one argument, to the tap set. This function will be called with anything sent via tap>. This function may (briefly) block (e.g. for streams), and will never impede calls to tap>, but blocking indefinitely may cause tap values to be dropped. Remember f in order to remove-tap

Examples

by earthfail on 2022-08-19 . May have evaluation errors. ▶

;; log to a file (defn log [x] (spit "event.log" (str x \newline) :append true)) ;; add log function to tap (add-tap log) ;;_=> returns nil (add-tap println) (tap> "hello") ;; prints hello ;; returns true if successful ;; event.log: ;; hello\n (tap> "clojure") ;; prints clojure ;; returns true ;; event.log: ;; hello\n ;; clojure\n ;; the tap set is a hash-set so adding the same function twice has no effect (add-tap println) (tap> "<3") ;; prints <3 ;; returns true ;; event.log: ;; hello\n ;; clojure\n ;; <3\n

by djblue on 2022-08-26 . May have evaluation errors. ▶

;; Your tap target function can do interesting things when it receives a value ;; before printing it (require '[clojure.datafy :refer [datafy]]) (add-tap (comp prn datafy))

See also

• clojure.core/tap> (1)
• clojure.core/remove-tap
• clojure.datafy/datafy (0)

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