xuwei-k

scala> def foo(a: => String){println("foo");println(a)}
foo: (a: => String)Unit

scala> def bar(b:Int):String = {println("bar "+b);  ( b * 2 ).toString }
bar: (b: Int)String

scala> foo(bar(2))
foo
bar 2
4

xuwei-k

scala> scala> implicit val yearOrdering = new Ordering[Language]{
  def compare(x: Language, y: Language) = x.year compare y.year
}
yearOrdering: java.lang.Object with Ordering[Language] = $anon$1@7910769b

scala> implicit val nameLengthOrdering = new Ordering[Language]{
  def compare(x: Language, y: Language) = x.name.length compare y.name.length
}
nameLengthOrdering: java.lang.Object with Ordering[Language] = $anon$1@38a3c5b6

xuwei-k

implicit def toGrepCallable(list:List[String]) = new {
  def grep[A](regex:String)(func:String => A = identity _):List[A] = 
    list.collect{
      case s if regex.r.findFirstIn(s).isDefined =>
      func(s)
    }
}

xuwei-k

Scala公式ページの論文一覧のページのhtmlをパースして、自動でpdfのファイルっぽいものを全部ダウンロードするだけのものです

xuwei-k

scala> sealed abstract class A

case object B extends A
case object C extends A

def hoge(xs:Map[A,Int]){ xs foreach println }

val list = Map(B -> 1 ,C -> 2)
defined class A
defined module B

xuwei-k

def byteIteratorFromURL(url:String):Iterator[Byte] = {
  val in = new java.net.URL(url).openStream
  Iterator.continually(in.read).takeWhile(_ != -1).map(_.toByte)
}

def byteStreamFromURL(url:String):Stream[Byte] = {
  val in = new java.net.URL(url).openStream
  Stream.continually(in.read).takeWhile(_ != -1).map(_.toByte)
}

xuwei-k

object Main{
  import scala.util.parsing.json.JSON

  def gistsUrl(user:String) = "http://gist.github.com/api/v1/json/gists/" + user
  
  def gistsFile(repo:String,fileName:String) = "https://raw.github.com/gist/" + repo + "/"+  fileName
  
  type jsonType = Map[String,List[Map[String,Any]]]
  
  def byteIteratorFromURL(url:String):Iterator[Byte] = {

xuwei-k

scala> DBObject("ccc" -> Map("aaa" -> "bbb"))
res54: com.mongodb.casbah.commons.Imports.DBObject = { "ccc" : [ [ "aaa" , "bbb"]]}

scala> DBObject("ccc" -> new java.util.HashMap[String,AnyRef](){put("aaa","bbb")})
res55: com.mongodb.casbah.commons.Imports.DBObject = { "ccc" : { "aaa" : "bbb"}}

xuwei-k

// Scala実践プログラミング P177 http://amzn.to/nruUtV

printf("matched = %d%n",Stream.continually(readLine).takeWhile(null!=).zipWithIndex.collect{case(l,i)if l.matches("(.*%s.*)".format(args(0)))=>printf("%3d: %s%n",i+1,l)}.size)

xuwei-k

scala> import com.mongodb.casbah.Imports._
import com.mongodb.casbah.Imports._

// MongoDBObjectつくる
scala> val obj = MongoDBObject("a" -> 1)
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
obj: com.mongodb.casbah.commons.Imports.DBObject = { "a" : 1}