noahlz

trait Huggable {
  self: Pet =>

  def hug() :Unit = println("Dawww...!")
}

class Pet

class Puppy extends Pet with Huggable

noahlz

package app;

object Bar {
  implicit val b: Bar = new Bar(5)
}

class Bar(val x: Int) {
  def doStuff() {
    println(x)
  }

noahlz

// See: http://nurkiewicz.blogspot.com/2012/04/secret-powers-of-foldleft-in-scala.html
def transformString(s: String, fns: List[Function1[String,String]]) :String = 
  (s /: fns) { (s: String, f: Function1[String,String]) => f apply s }

val toUpper = (s: String) => s.toUpperCase
val reverse = (s: String) => s.reverse
val disenvowel = (s: String) => s filterNot { Set('a','e','i','o','u') contains _ }

// scala> transformString("blah",List(disenvowel))
// res175: String = blh

noahlz

// Reference: http://www.cforcoding.com/2012/01/interview-programming-problems-done.html

object PascalsTriangle {
  
  def nextrow(prev: List[Int]) :Stream[List[Int]] =  {

    val curr = collection.mutable.ArrayBuffer(1)

    for(i <- 1 until prev.length) {
      curr += prev(i - 1) + prev(i) 

noahlz

Free excerpt from TypeSafe (pdf): Scala for the Impatient

Class Setters

I discovered the special syntax for a field setter:

class Person {
  private var privateAge = 0 // Make private and rename
  def age = privateAge
 def age_ = (newValue: Int) {

noahlz

[noahlz:stringly]$ git checkout master
Switched to branch 'master'
[noahlz:stringly]$ git log -6 --oneline
d230ce9 merge branch develop [no ci]
908e62b only build master
0416e6c Added a few words about Perforate to the readme.
621565e only build master
5832d26 Added a few words about Perforate to the readme.
3ca1764 Merge branch 'issues/6/upgrade-perforate'
[noahlz:stringly]$ git reset --soft HEAD~3

noahlz

====== Benching (Character/isLetter ^char c) ====== 
WARNING: Final GC required 3.956775511289807 % of runtime
amd64 Linux 3.2.0-48-generic 2 cpu(s)
Java HotSpot(TM) 64-Bit Server VM 23.21-b01
Runtime arguments: -XX:+TieredCompilation -XX:TieredStopAtLevel=1 -Dclojure.compile.path=/tmp/oneoff/classes -Doneoff.version=0.1 -Dfile.encoding=UTF-8 -Dclojure.debug=false
Evaluation count : 5580540 in 60 samples of 93009 calls.
      Execution time sample mean : 11.046857 µs
             Execution time mean : 11.046903 µs
Execution time sample std-deviation : 24.758483 ns
    Execution time std-deviation : 24.947300 ns

noahlz

user=> (set! *warn-on-reflection* true)
true
user=> (defn is-letter? [c] (Character/isLetter c))
Reflection warning, NO_SOURCE_PATH:1:22 - call to isLetter can't be resolved.
#'user/is-letter?

user=> (defn is-letter? [^char c] (Character/isLetter c))
user=> CompilerException java.lang.IllegalArgumentException: Only long and double primitives are supported, compiling:(NO_SOURCE_PATH:1:1) 

;; Ugh...no.

noahlz

Apache Maven 3.0.5 (r01de14724cdef164cd33c7c8c2fe155faf9602da; 2013-02-19 08:51:28-0500)
Maven home: /home/nzucker/java/maven-latest
Java version: 1.6.0_31, vendor: Sun Microsystems Inc.
Java home: /home/nzucker/java/jdk1.6.0_31/jre
Default locale: en_US, platform encoding: UTF-8
OS name: "linux", version: "2.6.18-194.el5", arch: "amd64", family: "unix"
[INFO] Error stacktraces are turned on.
[DEBUG] Reading global settings from /home/nzucker/java/maven-latest/conf/settings.xml
[DEBUG] Reading user settings from /home/nzucker/.m2/settings.xml
[DEBUG] Using local repository at /home/nzucker/.m2/repository

noahlz

user=> (concat '(1 2 3) '(4 5 6))
(1 2 3 4 5 6)

user=> (conj '(1 2 3) '(4 5 6))
((4 5 6) 1 2 3)

user=> (cons '(1 2 3) '(4 5 6))
((1 2 3) 4 5 6)

user=> (list '(1 2 3) '(4 5 6))