clojure-util

General helpful aspects for clojure projects (caching, I/O, ...)

##ConsoleProgress##

tired of logging the progress in consecutive lines wasting console space. do you want to implementing logging schemes implying only small I/O load. This class gives you a progress bar in the console that is only updated when necessary and does a time tracing as well. Line feed is done after the progress went to 100 percent.

• Clojure example

(import '[org.lambdaroyal.util ConsoleProgress])

(def p (ConsoleProgress. \-))

(loop [i 0]
    (if
        (> i 100) nil
        (do
            (.showProgress p "I'm waitin" i)
            (Thread/sleep 5)
            (recur (inc i)))))

gives you (in the end)

[----------] 100% I'm waitin 579ms

• Java Example

ConsoleProgress progress = new org.lambdaroyal.util.ConsoleProgress("*");
progress.showProgress("task1", 0);
progress.showProgress("task2", 0);
progress.showProgress("task12",11);
progress.showProgress("task12", 100);

##Localcache##

Returns a memoized version of the application of the provided function. This version is associated with the provided key. Repeatedly arguments for the same key return the previously computed application or block until the function application returns.

• Clojure example

(require '[org.lambdaroyal.util.localcache :as cache])

(defn long-running-random-generator [x]
    (do
        (Thread/sleep 1000)
        (rand-int x)))

;;this is the first call - nothing is cached so far        
(cache/cache :foo long-running-random-generator 5)

;;this is the second call with the same signature (parameter) - returns immediately
(cache/cache :foo long-running-random-generator 5)

;;this is the third call - with another parameter set - so the function is applied and the result provided into the cache
(cache/cache :foo long-running-random-generator 10)