ericnormand

The Sieve of Eratosthenes is a neat way to find all of the prime numbers below some number. If you do it on paper (and I suggest you do), you can easily find all primes below 100 within a few minutes. The challenge this week is to write a version in Clojure that lets you calculate all the primes below a given number n.

The biggest challenge with this is that you might run into problems with stack overflows or speed. Make sure the algorithm can still run with n=100,000.

I'd love to see your answers. Bonus points for creative and innovative solutions. I'll share the best next week. Fire up a REPL, try it out, and send me your answers. (Please note that, unless you tell me otherwise, I will share your name in the newsletter if you send me an answer.)

ericnormand

(def feature-version "0.1")
(def build-version (or (System/getenv "BUILD_NUMBER") "HANDBUILT"))
(def release-version (str feature-version "." build-version))
(def project-name "nittygrits")

(defproject nittygrits release-version
  :uberjar-name ~(str project-name ".jar")
  :manifest {"Implementation-Version" ~release-version}

  :jar-name ~(str project-name "-" release-version ".jar")

ericnormand

// takes a function of one or more arguments
// the first argument has to be the id
function make_idempotent(f) {
  const already_performed = {};
  return function(id, ...args) {
    if(already_performed[id])
      return {status: "already performed"};
    already_performed[id] = true;
    return {

ericnormand

(ns spec-test.core
  (:require [clojure.spec.alpha :as spec]))

(defn paircat' [[a1 a2] [b1 b2]]
  [(concat a1 b1) (concat a2 b2)])

(defn paircat [& pairs]
  (reduce paircat' [[] []] pairs))

(defn mappaircat [f coll]

ericnormand

Boot

Boot is another build tool for Clojure. If you're using it, there is a ClojureScript build task called [boot-cljs].

In your boot.boot file, add this dependency (check [Clojars][clojarsboot] for the latest version):

ericnormand

#
#Fri Mar 20 11:38:40 CDT 2015
root=/Users/eric/dw/ballot-scout
classpath=/Users/eric/dw/ballot-scout/test\:/Users/eric/dw/ballot-scout/src\:/Users/eric/dw/ballot-scout/test-resources\:/Users/eric/dw/ballot-scout/config\:/Users/eric/dw/ballot-scout/resources\:/Users/eric/dw/ballot-scout/target/classes\:/Users/eric/.m2/repository/ns-tracker/ns-tracker/0.2.1/ns-tracker-0.2.1.jar\:/Users/eric/.m2/repository/com/datomic/datomic-lucene-core/3.3.0/datomic-lucene-core-3.3.0.jar\:/Users/eric/.m2/repository/org/apache/pdfbox/fontbox/1.8.8/fontbox-1.8.8.jar\:/Users/eric/.m2/repository/clj-tuple/clj-tuple/0.1.7/clj-tuple-0.1.7.jar\:/Users/eric/.m2/repository/com/fasterxml/jackson/core/jackson-databind/2.1.1/jackson-databind-2.1.1.jar\:/Users/eric/.m2/repository/org/jgroups/jgroups/3.2.12.Final/jgroups-3.2.12.Final.jar\:/Users/eric/.m2/repository/org/apache/tomcat/tomcat-juli/7.0.27/tomcat-juli-7.0.27.jar\:/Users/eric/.m2/repository/com/cemerick/piggieback/0.1.0/piggieback-0.1.0.jar\:/Users/eric/.m2/repository/com/cogni

ericnormand

#
#Fri Mar 20 11:05:40 CDT 2015
root=/Users/eric/dw/ballot-scout
classpath=/Users/eric/dw/ballot-scout/test\:/Users/eric/dw/ballot-scout/dev-src\:/Users/eric/dw/ballot-scout/src\:/Users/eric/dw/ballot-scout/dev-resources\:/Users/eric/dw/ballot-scout/env-configs/ballot-scout/dev/resources\:/Users/eric/dw/ballot-scout/dev-resources\:/Users/eric/dw/ballot-scout/config\:/Users/eric/dw/ballot-scout/resources\:/Users/eric/dw/ballot-scout/target/classes\:/Users/eric/.m2/repository/ns-tracker/ns-tracker/0.2.1/ns-tracker-0.2.1.jar\:/Users/eric/.m2/repository/com/datomic/datomic-lucene-core/3.3.0/datomic-lucene-core-3.3.0.jar\:/Users/eric/.m2/repository/org/apache/pdfbox/fontbox/1.8.8/fontbox-1.8.8.jar\:/Users/eric/.m2/repository/clj-tuple/clj-tuple/0.1.7/clj-tuple-0.1.7.jar\:/Users/eric/.m2/repository/com/fasterxml/jackson/core/jackson-databind/2.1.1/jackson-databind-2.1.1.jar\:/Users/eric/.m2/repository/org/jgroups/jgroups/3.2.12.Final/jgroups-3.2.12.Final.jar\:/Users/eric/.m2/repository/org/apache/tomcat/tomcat-juli

ericnormand

{
   "amazon-cache": {
      "mappings": {
         "listings": {
            "properties": {
               "asin": {
                  "type": "string",
                  "index": "not_analyzed"
               },
               "categories": {

ericnormand

{
   "big-feed-index": {
      "mappings": {
         "listings": {
            "properties": {
               "asin": {
                  "type": "string",
                  "index": "not_analyzed"
               },
               "categories": {

ericnormand

package edntester;


import us.bpsm.edn.Keyword;
import us.bpsm.edn.parser.Parseable;
import us.bpsm.edn.parser.Parser;
import us.bpsm.edn.parser.Parsers;
import us.bpsm.edn.printer.Printers;

import java.util.ArrayList;