notyy

import Control.Monad
import Control.Monad.State
import Control.Monad.Writer

type User = String
type Log = [String]

login :: String -> State [User] ()
login u = do
  modify (u:)

notyy

{-# LANGUAGE NoMonomorphismRestriction #-}

import Control.Monad.State
import Control.Monad.Identity

test1 = do        -- when apply on init state 0
  a <- get        -- a = (0,0)
  modify (+1)     -- (0,1)
  b <- get        -- b = (1,1)
  return (a,b)    -- why result is ((0,1),1)

notyy

def connect[A,B,C](f1: A => B, f2: A => B, f3: B => B => C): (A => C) = x => { 
  f3(f1(x))(f2(x))
}

def add2 = (x:Int) => x + 2

def multi3 = (x:Int) => x * 3

def addThem = (x:Int) => (y:Int) => x + y

notyy

http://www.spoj.pl/problems/TEST/

import scala.io._

object Main { 
  def main(args: Array[String]) { 
    val source = Source.stdin
    source.getLines.takeWhile((x=> x != "42")).foreach(println)
  }
}

notyy

问题描述，有一个横8纵8的国际象棋棋盘，也就是坐标x,y都在（1..8)的范围内。
在棋盘的任意坐标上放一个马，马的走步规则，跟中国象棋差不多。。。如果不了解的话请谷歌之
现在给定棋盘上任意坐标，问这个马是否有可能精确的在第3步上走到该坐标？

=======================下面的解法译自haskell==================================
def moveKnight: (Int,Int) => List[(Int,Int)] = (c,r) => { 
  List((c+2,r-1),(c+2,r+1),(c-2,r-1),(c-2,r+1),
       (c+1,r-2),(c+1,r+2),(c-1,r-2),(c-1,r+2)) filter (pos => (1 to 8).contains(pos._1) && (1 to 8).contains(pos._2))
}

notyy

import scala.io._

object Main { 
  def main(args: Array[String]) {
    echo(Console.readLine)
  }

  def echo(line: => String): Unit = line match{ 
    case "42"         => ()
    case (x:String)   => println(x);echo(Console.readLine);

notyy

import scala.math._
def toNum(base:Int, src: List[Int]): Int = (base, src) match { 
  case (_,Nil) => 0
  case (b, (x::xs)) => x * pow(b,xs.length).toInt + toNum(b,xs)
}

=======================
scala> toNum(10,List(1,2,3,4))
res7: Int = 1234

notyy

def qs[T <% Ordered[T]](l: List[T]): List[T] = l match { 
  case Nil => Nil
  case (x :: xs) => {
    val (less,greater) = xs partition (_ <= x)
    qs(less) ++ (x :: qs(greater))
  }
}

notyy

def shuffle[T](t: Int, l: List[T]): List[T] = (t,l) match { 
  case (0, _) => Nil
  case (x, Nil) => Nil
  case (x, ls) => { 
    import scala.util.Random
    val r = ls(Random.nextInt(ls.length))
    r :: shuffle(x-1, ls.filterNot(item => item == r))
  }
}

notyy

(load "~/.emacs.d/haskell-mode/haskell-site-file")
(add-to-list 'load-path "~/.emacs.d/color-theme-6.6.0")

;; (add-hook 'haskell-mode-hook 'turn-on-haskell-doc-mode)
;; (add-hook 'haskell-mode-hook 'turn-on-haskell-indent) 
(require 'color-theme)
(color-theme-initialize)
(color-theme-hober)
(put 'downcase-region 'disabled nil)