overly-simplistic-almost-monadic-error-handling.clj

(defn e-bind [f]
  (fn [v]
    (let [[e *v] (try [true (f v)] (catch Exception e [false (.toString e)]))]
          (if e *v (handler e *v f)))))

;; presumably this would do something constructive, and
;; probably expect more preceding state from preceding computations
;; in a domonad form

(defn handler [s x f] 
  (println "input was" s) 
  (println "exception was" x) 
  (println "next fn was " f)
  (println (str "... recovering"))
  (f #(println :safe-continuation)))

((e-bind #(%)) #(println "foo"))
=>
foo

((e-bind #(%)) nil)
=>
input was false
exception was java.lang.NullPointerException
next fn was  #<user$eval__8118$fn__8120 user$eval__8118$fn__8120@7abccf9a>
... recovering
:safe-continuation