channingwalton

21:15:22.745 ERROR akka://ENSIME/user/$b o.e.s.SocketHandler - Error in socket reader: 
java.lang.NumberFormatException: For input string: "new Wo"
	at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65) ~[na:1.8.0_31]
	at java.lang.Integer.parseInt(Integer.java:580) ~[na:1.8.0_31]
	at java.lang.Integer.valueOf(Integer.java:740) ~[na:1.8.0_31]
	at org.ensime.server.FramedStringProtocol$class.readString(FramedStringProtocol.scala:39) ~[server_2.11-0.9.10-SNAPSHOT.jar:0.9.10-SNAPSHOT]
	at org.ensime.server.SwankProtocol.readString(SwankProtocol.scala:10) ~[server_2.11-0.9.10-SNAPSHOT.jar:0.9.10-SNAPSHOT]
	at org.ensime.server.S≈wankProtocol.read(SwankProtocol.scala:15) ~[server_2.11-0.9.10-SNAPSHOT.jar:0.9.10-SNAPSHOT]
	at org.ensime.server.SocketHandler$$anon$1.run(SocketHandler.scala:43) ~[server_2.11-0.9.10-SNAPSHOT.jar:0.9.10-SNAPSHOT]

channingwalton

module Main 

rev : Vect n a -> Vect n a
rev Nil = Nil
rev (x :: xs) = (rev xs) ++ (x :: Nil)

main : IO ()
main = putStrLn $ show $ rev [1,2,3]

fails to compile with

channingwalton

// No case classes
object Consoles {

  trait ConsoleAlg[F[_]] {
    def readLine: F[Option[String]]

    def printLine(line: String): F[Unit]
  }

  trait Console[+A] {

channingwalton

import scalaz._

object LensFu extends App {

  case class FieldValue[T](name: String, v: T)

  case class Field[T, F](name: String, lens: Lens[T, F]) {
    def >=>[G](field: Field[F, G]): Field[T, G] = Field(name + "." + field.name, lens >=> field.lens)
    def get(v: T): FieldValue[F] = FieldValue(name, lens.get(v))
    def set(a: T, b: F): T = lens.set(a, b)

channingwalton

case class Foo[T](x: T) {
  def map[B](f: T => B) = Foo(f(x))
}

object OldWay {

  def combineLatest[T1, T2](e1: Foo[T1], e2: Foo[T2]): Foo[(T1, T2)] = Foo((e1.x, e2.x))

  def combineLatest[T1, T2, T3](e1: Foo[T1], e2: Foo[T2], e3: Foo[T3]): Foo[(T1, T2, T3)] =
    combineLatest(combineLatest(e1, e2), e3) map {

channingwalton

object MonoidHomomorphism extends App {

  import scalaz._
  import Scalaz._

  /**
   * Turn any null into the Zero value for its type
   */
  def nullAsZero[T: Monoid : Equal](a: T) = if (a == null) implicitly[Monoid[T]].zero else a

channingwalton

What Changed

I used to automount on OSX by sudo vifs and adding a line like vault.local:/backup /Volumes/backup url auto,url==afp://;AUTH=No%20User%20Authent@vault.local/backup 0 0. But that no longer works on Maverick because the system deletes everything in /Volumes on wake/restart/something-or-other.

We are going to create a mount at /mnt/Resources. We need to edit the auto_master to tell it where the automount config for /mnt/Resources lives:

sudo vi /etc/auto_master

Now add this line at the top

channingwalton

 // ------------------------------------------------------
 // Combined List/Option/Either
 // ------------------------------------------------------
object MonadTransformers extends App {
  import scalaz._, Scalaz._
  import EitherT._

  type OptionTList[α] = ({ type λ[α] = OptionT[List, α] })#λ[α]

  val c1: EitherT[OptionTList, String, String] = eitherT[OptionTList, String, String](OptionT[List, \/[String, String]](List(some(\/-("c1a")), some(\/-("c1b")))))

channingwalton

object Trees extends App {

  def zero = '0'

  def repeat(c: Char)(n: Int) = c.toString * n

  def reflect(centre: Char)(s: String) = s.reverse + centre + s

  def pad(w: Int, c: Char)(s: String) = s.padTo(w - 1, c)

channingwalton

object PartialLensExample extends App {

  import scalaz._
  import Lens._
  import PLens._


  case class Bar(blub: Option[String])
  case class Foo(bar: Option[Bar])