lazyval

fun all_answers func [] = SOME []
fun all_answers func xs = let 
  fun loop [] = []
  |   loop (h::tail) = case (func h) of 
                         SOME x => x :: loop tail
                       | NONE => loop tail
  in case loop xs of
         [] => NONE
       | lst => SOME lst
  end

lazyval

object Foo {
  val bar = { println("bar"); 42 } 
}

object Foo2 {
  val bar = { println("bar") } 
}

// scala> Foo.bar
// bar

lazyval

val tens = Map (
    '2' -> "Twenty",
    '3' -> "Thirty",
    '4' -> "Fourty",
    '5' -> "Fifty",
    '6' -> "Sixty",
    '7' -> "Seventy",
    '8' -> "Eighty",
    '9' -> "Ninety"
    ) withDefaultValue("")

lazyval

require 'formula'

class Ant < Formula
  homepage 'http://ant.apache.org/'
  url 'http://www.apache.org/dyn/closer.cgi?path=ant/binaries/apache-ant-1.9.0-bin.tar.gz'
  sha1 '791418e7e80e3f28d6347528e8992a14f09058e7'

  def install
    rm Dir['bin/*.{bat,cmd,dll,exe}']
    libexec.install Dir['*']

lazyval

This gist contains data taken from http://www.doogal.co.uk/UKPostcodes.php in case it wouldn't be accessible latter. Gist was referenced from here: http://stackoverflow.com/q/15460607/298389

lazyval

JVM types are ZBSCIJFDL

lazyval

// it's good style to mark such objects/classes with sealed to guide complier 
// so it will check if match is exhaustive (all possible cases covered)
sealed abstract class Response
sealed abstract class Reason
abstract class TokenType

case class Token(t: TokenType) extends Response
case class Problem(reason: Reason) extends Response

case object InvalidResponse extends Reason

lazyval

import os
import os.path

buffer_in_bytes = 10 * 100 * 100

class RotatingFile:
  def __init__(self, filename, max_files, lines_per_file):
    self.file = open(filename, mode='w', buffering=buffer_in_bytes)
    self.filename = filename
    self.max_files = max_files

lazyval

val l1 = LinkedList(1)
l1.append(LinkedList(7))
l1
// res14: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 7)
 
val l0 = LinkedList[Int]()
l0.append(LinkedList(7))
l0
// res16: scala.collection.mutable.LinkedList[Int] = LinkedList()

lazyval

Epidemy Simulation
In this part, you are going to write an epidemy simulator based on the simulation framework seen in lecture and used in the circuit simulation.

The scenario is as follows: the world (“Scalia”) consists of regular grid of 64 rooms (8x8) where each room is connected to four neighbouring rooms. Each room may contain an arbitrary number of persons. Scaliosis – a vicious killer virus – rages with a prevalence rate of 1% among the peaceful population of Scalia. It spreads with a transmissibility rate of 40%. By prevalence rate, we mean that a certain portion of the population is infected to begin with. The transmissibility rate refers to the probability of one person to be infected.

In the beginning, 300 people are equally distributed among the rooms. Each step of the simulation corresponds to one simulated day. The disease and behaviour of people is simulated according to the following rules.

Rules
After each move (and also after the beginning of the simulation), a person moves to one of thei