retronym

package scalaz

import collection.generic.CanBuildFrom

class TraversableW[Coll, A](val value: Coll)(implicit ev: Coll <:< Traversable[A])  {
  def as[CC[X] <: Traversable[X]](implicit cbf1: CanBuildFrom[Coll, A, CC[A]] = null, cbfDefault: CanBuildFrom[Nothing, A, CC[A]]): CC[A] = {
    Option(cbf1) match {
      case Some(cbf) =>
        // A direct builder exists from the source collection to the target
        cbf(value).result

folone

/**
 * <b>Fixed Point Combinator is:</b>
 * Y = λf.(λx.f (x x)) (λx.f (x x))
 * 
 * <b>Proof of correctness:</b>
 * Y g  = (λf . (λx . f (x x)) (λx . f (x x))) g    (by definition of Y)
 * = (λx . g (x x)) (λx . g (x x))                  (β-reduction of λf: applied main function to g)
 * = (λy . g (y y)) (λx . g (x x))                  (α-conversion: renamed bound variable)
 * = g ((λx . g (x x)) (λx . g (x x)))              (β-reduction of λy: applied left function to right function)
 * = g (Y g)                                        (by second equality) [1]

milessabin

trait Companion[T] {
  type C
  def apply() : C
}

object Companion {
  implicit def companion[T](implicit comp : Companion[T]) = comp()
}

object TestCompanion {

RedBeard0531

// derived from http://en.wikipedia.org/wiki/Algorithms_for_calculating_variance#Parallel_algorithm

function map() {
    emit(1, // Or put a GROUP BY key here
         {sum: this.value, // the field you want stats for
          min: this.value,
          max: this.value,
          count:1,
          diff: 0, // M2,n:  sum((val-mean)^2)
    });

teamon

package controllers

import lib._
import play.api.mvc._
import play.api.libs.json._


object Auth extends Controller {

  val GITHUB = new OAuth2[GithubUser](OAuth2Settings(

tonymorris

case class ReaderWriterStateT[R, W, S, F[_], A](
  run: (R, S) => F[(W, A, S)]
) {
  def map[B](f: A => B)(implicit F: Functor[F])
      : ReaderWriterStateT[R, W, S, F, B] =
    ReaderWriterStateT {
      case (r, s) => F.map(run(r, s)) {
        case (w, a, s) => (w, f(a), s)
      }
    }

mpilquist

object RWS extends App {

  trait Pointed[P[_]] {
    def point[A](a: A): P[A]
  }

  trait PointedFunctor[PF[_]] extends Pointed[PF] with Functor[PF]

  implicit def listIsMonoid[A]: Monoid[List[A]] = new Monoid[List[A]] {
    def id: List[A] = Nil

guillaumebort

# --- !Ups

CREATE TABLE users(
  email                     VARCHAR(255) NOT NULL PRIMARY KEY,
  name                      VARCHAR(255)
);

CREATE TABLE subjects(
  id                        INTEGER NOT NULL AUTO_INCREMENT PRIMARY KEY,
  title                     LONGTEXT NOT NULL,

andreyvit

tmux cheat sheet

(C-x means ctrl+x, M-x means alt+x)

Prefix key

The default prefix is C-b. If you (or your muscle memory) prefer C-a, you need to add this to ~/.tmux.conf:

remap prefix to Control + a

xuwei-k

https://groups.google.com/d/msg/scala-user/Z54ncnC7XKA/AKfUwF5qDk0J