qzchenwl

import Data.List

isUnique :: (Ord a) => [a] -> Bool
isUnique = all (null . drop 1) . group . sort

cols = [0..7]
solutions = [vec | vec <- permutations cols
                 , isUnique [vec!!i + i | i <- cols]
                 , isUnique [vec!!i - i | i <- cols]]

qzchenwl

import Data.List

isUnique :: (Ord a) => [a] -> Bool
isUnique = all (null . drop 1) . group . sort

cols = [0..7]

solutions = [vec | vec <- permutations cols
                 , isUnique [vec!!i + i | i <- cols]
                 , isUnique [vec!!i - i | i <- cols]]

qzchenwl

getD n = getD' n 2 where
         getD' n factor | n == factor = factor
                        | n `mod` factor == 0 = getD' (n `div` factor) factor
                        | otherwise = getD' n (succ factor)

qzchenwl

-- file: ch15/Supply.hs
next = S $ do st <- get
              case st of
              [] -> return Nothing
              (x:xs) -> do put xs
                           return (Just x)

qzchenwl

import Control.Monad
import Data.Maybe

maybeToMonad :: (MonadPlus m) => Maybe a -> m a
maybeToMonad Nothing  = mzero
maybeToMonad (Just x) = return x

type Sheep = Int

father :: Sheep -> Maybe Sheep

qzchenwl

-- file: ch03/GrahamScan.hs

import Data.List
import Data.Ord

type Point = (Double, Double)

data Direction = LeftTurn
               | RightTurn
               | Straight

qzchenwl

{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE OverloadedStrings #-}

module Main where

import qualified Data.ByteString.Char8 as B
import qualified Data.Text as T
import           Data.Maybe
import           Snap
import           Snap.Snaplet.Heist

qzchenwl

#!/usr/bin/env python2
# -*- coding: utf-8 -*-
'''
convert Microsoft Word 2007 docx files to wiki markup files
'''

from lxml import etree
import zipfile
import string
import sys

qzchenwl

{-# LANGUAGE OverloadedStrings #-}
import Codec.Archive.Zip
import Data.ByteString.Lazy (getContents, putStrLn)
import Data.ByteString.Lazy.Char8 (ByteString)
import Prelude hiding (getContents, putStrLn)
import Data.Maybe (maybe)
import System.Environment (getArgs)
import System.Exit (exitFailure)

main = do filePath <- getArgs >>= parse

qzchenwl

module Main where

import Data.Ratio
import Data.Tree

data Label = Label
  { f1     :: (Rational -> Rational)
  , accept :: (Rational -> Bool)
  , f2     :: (Rational -> Rational)