pbalduino

$ cat /usr/share/calendar/calendar.lotr
/*
 * Lord Of The Rings
 *
 * $FreeBSD: src/usr.bin/calendar/calendars/calendar.lotr,v 1.2 2003/10/09 00:31:48 grog Exp $
 */

#ifndef _calendar_lotr_
#define _calendar_lotr_

pbalduino

mas que beleza
mão colando na mesa
quente demais

pbalduino

(defn foo [x]
  {:pre [(> x 10)]}
  (println x))
; output: 'user/foo

(foo 2)
; output: AssertionError Assert failed: (> x 10)  user/foo (NO_SOURCE_FILE:1)

(foo 11)
; output: 11

pbalduino

(defn start-thread [f]
  (.start (Thread. f)))

(let
    [sum    (future (apply + (range 1e7)))
     answer (promise)]
     
    (println "0. Started...")

    (start-thread

pbalduino

(defn len [x]
  (.length x))
 
(defn len2 [^String x]
  (.length x))

(time (reduce + (map len (repeat 1000000 "asdf"))))
; "Elapsed time: 8711.592674 msecs"

(time (reduce + (map len2 (repeat 1000000 "asdf"))))

pbalduino

(defn sleep []
  (Thread/sleep 1000))

(defn fast-computation [x]
  (* x 2))

(defn heavy-computation [x]
  (sleep)
  (* x 2))

pbalduino

; First we create a function. Let's try Fibonacci

(defn fib [n] 
  (if  (or (zero? n) (= n 1)) 
    1 
    (+  (fib (dec n) )  (fib (- n 2))))) 

; Se let's measure the time needed to run the function

(do

pbalduino

; without memoization

(defn fib [n]
  (if  (or (zero? n) (= n 1)) 
    1 
    (+  (fib (dec n) )  (fib (- n 2)))))

(time (fib 90))
; spent more than 30 minutes and I quit

pbalduino

(use '[clojure.core.match :only (match)])

(doseq [n (range 1 101)]
  (println
    (match [(mod n 3) (mod n 5)]
      [0 0] "FizzBuzz"
      [0 _] "Fizz"
      [_ 0] "Buzz"
      :else n)))

pbalduino

(ns euler.euler04-1)

(defn peel 
  "Peel a string like a banana, removing first and last character"
  [str]
  (butlast (rest str)))

(defn palindrome? 
  "Returns true or false if name is a palindrome.
   This recursive approach is slightly faster than compare with its reverse."