gakuzzzz

package disample

case class DiSampleConfig(foo: Int, bar: String)
object DiSampleConfig {
  implicit val configs: Configs[DiSampleConfig] = Configs { c =>
    DiSampleConfig(
      foo = c.get[Int]("foo"),
      bar = c.get[String]("bar")
    )
  }

halcat0x15a

Pipeモナドの紹介

Scalaの記事です。Haskellはあまり書けません。

Iterateeの複雑さから開放されたいのでPipe系ライブラリ使いましょうという記事です。

Iterateeとの比較や簡単な使い方についてつらつらと書いていきます。

Iterateeについて

halcat0x15a

(ns typelogic.lisp
  (:refer-clojure :exclude [==])
  (:require [clojure.core.logic :refer :all]
            [clojure.core.logic.dcg :refer :all]))

(defna expr [g x t]
  ([[[x t] . _] x t])
  ([[_ . g'] x t] (expr g' x t))
  ([_ ['fn [a] b] [::-> p q]]
     (fresh [g']

xuwei-k

sealed trait Status
sealed trait HasID extends Status
sealed trait NoID extends Status

case class User[S <: Status](
  firstName: String,
  lastName: String,
  age: Int,
  createdAt: java.util.Date,
  private val _id: Int = 0

xeno-by

~/210x $ scala -Xshow-phases
             phase name  id  description
             ----------  --  -----------
                 parser   1  parse source into ASTs, perform simple desugaring
          macroparadise   2  let our powers combine
                  namer   3  resolve names, attach symbols to named trees in paradise
         packageobjects   4  load package objects in paradise
                  typer   5  the meat and potatoes: type the trees in paradise
                         ...

halcat0x15a

def point(a: BufferedImage, b: BufferedImage) =
  for {
    points <- (for {
      ax <- 0.to(a.getWidth - b.getWidth).view
      ay <- 0.to(a.getHeight - b.getHeight).view
    } yield {
      for {
        bx <- 0.until(b.getWidth).view
        by <- 0.until(b.getHeight).view
      } yield (ax, ay) -> (bx, by)

mumoshu

Akkaのネットワーキングでは、2者間の通信を最小単位としてプロトコルを組む。

A <-- Protocol --> B

2者間のプロトコルの実装はPipelineと呼ばれる。 PipelineはAからのメッセージをBに通じるように翻訳し、一方でBからのメッセージをAに通じるように翻訳するという働きをする。

tototoshi

import sbt._
import sbt.Keys._

object ScalaoauthasyncBuild extends Build {

  lazy val scalaoauthasync = Project(
    id = "scala-oauth-async",
    base = file("."),
    settings = Project.defaultSettings ++ Seq(
      name := "scala-oauth-async",

halcat0x15a

(defn points [^BufferedImage image ^BufferedImage screen]
  (let [width (.getWidth image)
        height (.getHeight image)
        xrange (range width)
        yrange (range height)]
    (for [points
          (for [sx (range (- (.getWidth screen) width))
                sy (range (- (.getHeight screen) height))]
            (for [tx xrange
                  ty yrange]

seratch

package example

import scalikejdbc._, SQLInterpolation._, config._, async._
import org.fluentd.logger.scala._
import org.scalatest._, matchers._
import scala.concurrent._, duration.DurationInt, ExecutionContext.Implicits.global

class SampleSpec extends FlatSpec with ShouldMatchers {

  case class Name(id: Long, kanji: String, kana: String)