cluno

sealed trait Interact[A]

case class Ask(prompt: String)
  extends Interact[String]

case class Tell(msg: String)
  extends Interact[Unit]

trait Monad[M[_]] {
  def pure[A](a: A): M[A]

cluno

#!/bin/sh
exec scala -savecompiled "$0" "$@"

# Output
# --------------------------------------------------------
# Node(1,Node(2,Leaf(4),Leaf(5)),Node(3,Leaf(6),Leaf(7)))
# ========================================================
# size        7
# height      3
# leafCount   4

cluno

import Denotational._

/**
 * Video: http://www.parleys.com/play/53a7d2c9e4b0543940d9e553
 * Slide: https://dl.dropboxusercontent.com/u/7083182/scaladays-slides/DenotationalSemantics.compressed.pdf
 * 
 * For being a better Functional Programmer
 * "Fold and unfold for program semantics" by Graham Hutton 
 *  - http://eprints.nottingham.ac.uk/230/1/semantics.pdf
 * 

cluno

Installing pdnsd from homebrew as root user.

$ brew install pdnsd

$ sudo chown -R nobody /usr/local/var/cache/pdnsd

$ curl -L http://goo.gl/kMlyQ -o pdnsd.conf
$ mv pdnsd.conf /usr/local/etc
$ sudo chown root /usr/local/etc/pdnsd.conf

cluno

// Questions about \/ and Validation
object scalaz {

/*
This explanation might help. This is a compilable source file with revisions 
available at https://gist.github.com/tonymorris/8263051

Fact: All monads are applicative functors. As has been seen we can witness the
`Applicative` that arises from the `Monad` primitives. Let's illustrate this: