gberenfield

Clojure Destructuring Tutorial and Cheat Sheet

(Related blog post)

Simply put, destructuring in Clojure is a way extract values from a datastructure and bind them to symbols, without having to explicitly traverse the datstructure. It allows for elegant and concise Clojure code.

Vectors

gberenfield

Business Models

Advertising

Models	Examples
Display ads	Yahoo!
Search ads	Google

gberenfield

[:~/clojure/git/lib-noir on master]
λ rm -r ~/.m2/repository/leinjacker                                                                                                                                                                                                                                     1 ↵ ✭
[:~/clojure/git/lib-noir on master]
λ lein clean                                                                                                                                                                                                                                                                ✭
Retrieving leinjacker/leinjacker/0.4.1/leinjacker-0.4.1.pom from clojars
Retrieving leinjacker/leinjacker/0.3.2/leinjacker-0.3.2.pom from clojars
Retrieving leinjacker/leinjacker/0.2.0/leinjacker-0.2.0.pom from clojars
Retrieving leinjacker/leinjacker/0.3.2/leinjacker-0.3.2.jar from clojars
[:~/clojure/git/lib-noir on master]
λ lein deps                                                                         

gberenfield

[:~/clojure/git/lib-noir on master]
λ lein clean                                                                                                                                                                                                                                                            1 ↵ ✭
[:~/clojure/git/lib-noir on master]
λ lein deps                                                                                                                                                                                                                                                                 ✭
[:~/clojure/git/lib-noir on master]
λ lein doc                                                                                                                                                                                                                                                                  ✭
Exception in thread "main" java.lang.AssertionError: Assert failed: (vector? (:dependencies project []))
 

gberenfield

λ lein deps                                                                                                                                                                                                                                                                 ✭
Retrieving codox/codox/0.6.4/codox-0.6.4.pom from clojars
Retrieving codox/codox.leiningen/0.6.4/codox.leiningen-0.6.4.pom from clojars
Retrieving codox/codox/0.6.4/codox-0.6.4.jar from clojars
Retrieving codox/codox.leiningen/0.6.4/codox.leiningen-0.6.4.jar from clojars
[:~/clojure/git/lib-noir on master]
λ lein doc                                                                                                                                                                                                                                                                  ✭
Exception in thread "main" java.lang.AssertionError: Assert failed: (vector? (:dependencies project []))
  at leinjacker.deps$add_if_missing.invoke(deps.clj:43)
	at leiningen.d

gberenfield

(ns codelesson.week4-1
  (:require clojure.string)
  (:import (org.slf4j.impl.StaticLoggerBinder))
  (:import (javax.swing JFrame JPanel JButton JLabel JTextField JTextArea JScrollPane))
  (:import java.awt.event.ActionListener)
  (:import (javax.swing.event DocumentListener))
  (:import (java.awt GridBagLayout GridBagConstraints Dimension))
  (:import (java.util.concurrent TimeUnit)))

(def fees { :checking {:interest 0.02 :overdraft 0.10}

gberenfield

(ns codelesson.week3-2)

(def fees { :checking {:interest 0.02 :overdraft 0.10}
            :savings {:interest 0.04 :overdraft 0.075}
            :money-market {:interest 0.06 :overdraft 0.05}})
(def overall-overdraft (atom 100000))
(def accounts (atom []))

(defn random-account-type []
  (rand-nth [:checking :savings :money-market]))

gberenfield

(ns codelesson.week3-1
  (:require [clojure.string])
  (:gen-class))

(defn merge-with-padding [x y]
  " merge arrays x & y and padding the shorter of the two with nils "
  (let [cx (count x) cy (count y)]
    (if (not= cx cy)
      (if (< cx cy)
        (map #(vector %1 %2) (concat x (take (- cy cx) (repeat nil) )) y)

gberenfield

    # Because we have some old legacy users in the database, we need to override Devises method for checking if a password is valid.
    # We first ask Devise if the password is valid, and if it throws an InvalidHash exception, we know that we're dealing with a
    # legacy user, so we check the password against the SHA1 algorithm that was used to hash the password in the old database.  
    #SOURCES OF SOLUTION:
    # http://stackoverflow.com/questions/6113375/converting-existing-password-hash-to-devise
    # https://github.com/binarylogic/authlogic/blob/master/lib/authlogic/crypto_providers/sha512.rb
    # https://github.com/plataformatec/devise/blob/master/lib/devise/encryptors/authlogic_sha512.rb
    
    alias :devise_valid_password? :valid_password?
    def valid_password?(password)

gberenfield

(ns codelesson.week1-3)

(defn debugme [cp cd rp rd]
    (prn cp  cd )
    (prn rp)
    (prn rd)
    (println "-------------"))

(defn nomore [a b]
  (and (empty? a) (empty? b)))