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case class HttpRequest(path:String, queryStrings:Map[String,List[String]]) {
  def getPath() : String Or String = if(path.length>0) Good(path) else Bad("path cannot be empty.")
  def getQueryStrings() : ((List[String], Int), String) Or Every[String] = {
    validateKeyword(queryString.get("keyword")) zip validateNumber(queryString.get("number")) zip validateGender(queryString.get("gender"))
  }
  def validateKeyword(value:Option[List[String]]) : List[String] Or One[String] = {
    if(value.isDefined && value.get.length>0) Good(value.get) else Bad(One("No keyword."))
  }
  def validateNumber(value:Option[List[String]]) : Int Or One[String] = {
    try{

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val a : Option[String] = Some("abc")

if(a.isEmpty)
  println("do something if a has value "+a.get)
else
  println("do something if a is empty")

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import java.io.{FileOutputStream, ByteArrayOutputStream, ByteArrayInputStream}
import java.util.zip.GZIPInputStream
import java.util.zip.GZIPOutputStream
import java.io._

object GzipHelper {

  implicit def StringGzipConvertor(str:String) = new {
    def toGzipBytes(charset:String="UTF-8") = compress(str,charset)
    def toGzipBytesString(charset:String="UTF-8") = new String(compress(str,charset).map(_.toChar))

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// Use Gists to store code you would like to remember later on
console.log(window); // log the "window" object to the console

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Shortener Design Concept

Shortener

Shortener trait is an interface that defines core functions of shortener which is shorter & taller.

trait Shortener {
  def shorter(url:String)(implicit dbClient : DBClient, tracerInfo: TracerInfo) : String Or BaseException
  def taller(short:String)(implicit dbClient : DBClient, tracerInfo: TracerInfo) : String Or BaseException

}

joecwu

published	tags
true	ScaVaToScala Scala Scalaz Programming

[ScaVa->Scala] Scalaz Writer Monad

這篇同步發佈在我的Blog和Gist。

之前一篇 [ScaVa->Scala] Scala中使用Reader Monad來實現Dependency Injection ，裡面提到了Scalaz中的Reader Monad，有Reader當然也要有個Writer呀!!

joecwu

published	tags
true	ScaVaToScala Scala Scalaz Programming

[ScaVa->Scala] Scalaz Task 取代Scala Future來進行非同步處理的另一個選擇

這篇同步發佈在我的Blog和Gist。

Scala的Future用起來有什麼問題？

在Scala中，我們要處理asynchronous computations的時候應該都知道有Future這個好用的東西，但Future monad常讓我在進行error handling的時候有點困擾，我本來的回傳值若是有"成功"或"失敗"兩種case的時候，我們可以用Scalaz的disjuction或是Scalactic的Or來處理，但是加上Future後的結果會變成：

joecwu

published	tags
true	Docker

[Docker] Push Error

這篇同步發佈在我的Blog和Gist。

背景

joecwu

published	tags
true	ScalaInDepth Scala Programming

[Scala In Depth] Scala Case Classes

這篇同步發佈在我的Blog和Gist。

這篇文章，基本上是參考這篇Scala Case Classes In Depth來寫的，閱讀吸收後以我的例子與描述方式以中文寫下。

joecwu

#!/bin/sh

# Make sure to:
# 1) Name this file `backup.sh` and place it in /home/ubuntu
# 2) Run sudo apt-get install awscli to install the AWSCLI
# 3) Run aws configure (enter s3-authorized IAM user and specify region)
# 4) Fill in DB host + name
# 5) Create S3 bucket for the backups and fill it in below (set a lifecycle rule to expire files older than X days in the bucket)
# 6) Run chmod +x backup.sh
# 7) Test it out via ./backup.sh