martintrojer

(ns cljpuzzle.core
  (:use [clojure.math.combinatorics]))

(defn solve-logic-puzzle []
  (let [people [:amaya :bailey :jamari :jason :landon]]
    (first
      (for [[fortune time cosmopolitan us-weekly vogue] (permutations people) ; magazines
            [asiago blue-cheese mascarpone mozzarella muenster] (permutations people) ; cheeses
            ; We bind the reservations in two steps, so we have a name for the overall order
            reservations (permutations people)

martintrojer

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

(defn evaluate [env [sym x y]]
  (match [sym]
    ['Number]   x
    ['Add]      (+ (evaluate env x) (evaluate env y))
    ['Multiply] (* (evaluate env x) (evaluate env y))
    ['Variable] (env x)))
    
(def environment {"a" 3, "b" 4, "c" 5})

martintrojer

(defn re?
  ([p]
     (fn [s] (re-find (re-pattern p) (str s))))
  ([p s] ((re? p) s)))

(defn mapentry-matches? [pat [k v]]
  (or (re? pat (-> k str string/lower-case))
      (re? pat (-> v str string/lower-case))))

;; filter keys and values in json-like nested maps and vectors

martintrojer

(def pool (java.util.concurrent.Executors/newFixedThreadPool 2))
(def l1 (java.util.concurrent.CountDownLatch. 1))
(def l2 (java.util.concurrent.CountDownLatch. 1))

(defn worker [] (.await l1) (println "l1") (.await l2) (println "done!"))
(dotimes [_ 4] (.submit pool worker))

(.countDown l1)
;; l1
;; l1

martintrojer

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

(defn evaluate [env [sym x y]]
  (match [sym]
    ['Number]   x
    ['Add]      (+ (evaluate env x) (evaluate env y))
    ['Multiply] (* (evaluate env x) (evaluate env y))
    ['Variable] (env x)))
    
(def environment {"a" 3, "b" 4, "c" 5})

martintrojer

def sqrtStream(x: Double): Stream[Double] = {
  def improve(guess: Double) = (guess + x / guess) / 2
  lazy val guesses: Stream[Double] = 1 #:: (guesses map improve)
  guesses
}

sqrtStream(4).take(10).toList

martintrojer

import scala.io.Source

object mnem {
  val in = Source.fromURL("http://lamp.epfl.ch/files/content/sites/lamp/files/teaching/progfun/linuxwords.txt")

  val words = in.getLines.toList filter (word => word forall (c => c.isLetter))

  val mnem = Map(
  	'2' -> "ABC", '3' -> "DEF", 4 -> "GHI", '5' -> "JKL",
  	'6' -> "MNO", '7' -> "PQRS", '8' -> "TUV", 9 -> "WXYZ")

martintrojer

(defne not-membero [x l]
  ([_ []])
  ([_ [h . t]]
    (!= x h)
    (not-membero x t)))

(defne subseto [s1 s2]
  ([() _])
  ([[x . xs] _]
    (membero x s2)

martintrojer

(ns cl-graph
  (:refer-clojure :exclude [==])
  (:use clojure.core.logic))

;; Directed Acyclic Graphs

(defrel edge a b)

;;    a
;;    |

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(ns graph-cl
  (:refer-clojure :exclude [==])
  (:use clojure.core.logic))

(defrel edge a b)

(fact edge :b :a)
(fact edge :c :a)
(fact edge :d :b)
(fact edge :d :c)