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@stuarthalloway
stuarthalloway / atomic_state_update.clj
Last active November 25, 2017 19:26
Update state with a pure function
;; fixed version of 'state' at http://mishadoff.com/blog/clojure-design-patterns/#episode-3-state
;; takeaway: if you call 'swap!' twice on the same atom, you are probably making a mistake
(def user {:name "Jackie Brown"
:balance 0
:subscription? false})
(def ^:const SUBSCRIPTION_COST 30)
(defn pay
@valter-silva-au
valter-silva-au / install-intellij.sh
Created August 28, 2017 12:51
How to install Intellij Community Edition with homebrew-cask
$ brew cask install caskroom/cask/intellij-idea-ce
@hadielmougy
hadielmougy / gist:5d468409e2e5d75e1f33fba92cca721b
Created March 23, 2017 14:40 — forked from dekellum/gist:4171049
powerset in clojure using sets,union
(ns powerset.core-test
(:use (clojure set test)))
(defn powerset [s]
(apply union
#{s} ;the complete set of all s
(map (fn [i] (powerset (disj s i))) s)))
(deftest test-powerset
(is (= #{#{}}
@ghoseb
ghoseb / clj_spec_playground.clj
Last active March 30, 2019 22:35
Examples of Clojure's new clojure.spec library
(ns clj-spec-playground
(:require [clojure.string :as str]
[clojure.spec :as s]
[clojure.test.check.generators :as gen]))
;;; examples of clojure.spec being used like a gradual/dependently typed system.
(defn make-user
"Create a map of inputs after splitting name."
([name email]
@jpalala
jpalala / how-to-setup-mac-elasticsearch.md
Created September 11, 2015 08:28
setting up elasticsearch on your mac with brew

Install va homebrew

If you don't have homebrew installed - get homebrew here

Then run: brew install elasticsearch

Configuration

Update the elasticsearch configuration file in /usr/local/etc/elasticsearch/elasticsearch.yml.

@staltz
staltz / introrx.md
Last active July 22, 2024 09:31
The introduction to Reactive Programming you've been missing
@roryokane
roryokane / ExampleFilter.java
Created March 17, 2014 19:13
Java generic pipe and filter classes, plus examples
package pipe_foundations.example;
import pipe_foundations.Pipe;
import pipe_foundations.SimpleFilter;
public class ExampleFilter extends SimpleFilter<Integer, String> {
public ExampleFilter(Pipe<Integer> input, Pipe<String> output) {
super(input, output);
}
@timyates
timyates / Currying.java
Last active March 7, 2020 07:11
Currying and composition in Java 8
package java8tests ;
import java.util.function.BiFunction ;
import java.util.function.Function ;
public class Currying {
public void currying() {
// Create a function that adds 2 integers
BiFunction<Integer,Integer,Integer> adder = ( a, b ) -> a + b ;
@halgari
halgari / gist:7028120
Last active January 31, 2018 12:32
Async Agents via core.async
(use 'clojure.core.async)
(defprotocol ISendable
(channel [this]))
(defn async-agent [state]
(let [c (chan Long/MAX_VALUE) ;; <<-- unbounded buffers are bad, but this matches agents
a (atom state)]
(go-loop []
(when-let [[f args] (<! c)]
@bmarcot
bmarcot / knapsack_problem.scala
Last active June 28, 2017 13:41
The Knapsack Problem, in Scala -- Keywords: dynamic programming, recursion, scala.
def knapsack_aux(x: (Int, Int), is: List[Int]): List[Int] = {
for {
w <- is.zip(is.take(x._1) ::: is.take(is.size - x._1).map(_ + x._2))
} yield math.max(w._1, w._2)
}
def knapsack_rec(xs: List[(Int, Int)], is: List[Int]): List[List[Int]] = {
xs match {
case x :: xs => knapsack_aux(x, is) :: knapsack_rec(xs, knapsack_aux(x, is))
case _ => Nil