8 ways to report errors in Haskell | Random Hacks
Random code snippets, projects and musings about software from Eric Kidd, a developer and occasional entrepreneur. You're welcome to contact me! Mar 10, 2007 • by Eric Kidd Haskell is a marvellous language, but there are some things I don’t like about it. My least favorite: Haskell has no fewer than 8 different APIs for reporting errors. To make a bad situation worse, the choice of API varies betw
Mapを極める - key->valueの索引の使い方 | Scala Cookbook
Mapは key -> valueの索引のためのデータ構造。keyの値には重複を許さない。 Mapの作成 scala> val m = Map(1 -> "Apple", 2 -> "Banana", 3 -> "Chocolate") m: scala.collection.immutable.Map[Int,java.lang.String] = Map(1 -> Apple, 2 -> Banana, 3 -> Chocolate) 1 -> "Apple"の部分では、(1, "Apple")のTupleが生成され、最終的にMap.apply(elems:(A, B)*)が呼ばれている。 Builderを使ってMapを作成 val m = { val b = Map.newBuilder[Int, String] b += 1 -> "Apple" b += 2 -> "Banana
How to apply bindValue method in LIMIT clause?
Here is a snapshot of my code: $fetchPictures = $PDO->prepare("SELECT * FROM pictures WHERE album = :albumId ORDER BY id ASC LIMIT :skip, :max"); $fetchPictures->bindValue(':albumId', $_GET['albumid'], PDO::PARAM_INT); if(isset($_GET['skip'])) { $fetchPictures->bindValue(':skip', trim($_GET['skip']), PDO::PARAM_INT); } else { $fetchPictures->bindValue(':skip', 0, PDO::PARAM_INT); } $fetchPictures-
AngularJS フレームワークについて
.app 1 .dev 1 #11WeeksOfAndroid 13 #11WeeksOfAndroid Android TV 1 #Android11 3 #DevFest16 1 #DevFest17 1 #DevFest18 1 #DevFest19 1 #DevFest20 1 #DevFest21 1 #DevFest22 1 #DevFest23 1 #hack4jp 3 11 weeks of Android 2 A MESSAGE FROM OUR CEO 1 A/B Testing 1 A4A 4 Accelerator 6 Accessibility 1 accuracy 1 Actions on Google 16 Activation Atlas 1 address validation API 1 Addy Osmani 1 ADK 2 AdMob 32 Ads
REST APIs with Symfony2: The Right Way
Designing a REST API is not easy. No, really! If you want to design an API the right way, you have to think a lot about everything, and either to be pragmatic or to be an API terrorist. It’s not just about GET, POST, PUT, and DELETE. In real life, you have relations between resources, the need to move a resource somewhere else (think about a tree), or you may want to set a specific value to a reso
scala.Option | Scalaの標準ライブラリを使ってみる | mwSoft
概要 結果をラップしたSome(値)かNoneを持つクラス。 nullかもしれないものはOptionでラップしておくことで、すべてのクラスに対してnullを気にしなければいけない現状を解決してくれるかもしれない。 Scaladoc http://www.scala-lang.org/api/current/scala/Option.html コンストラクタ 引数がnullならNoneを、それ以外ならSome(引数)を返す。NoneとSomeはそれぞれOptionを継承している。ちなみにOption自体はabstract。 NoneはisEmptyに対してtrueを、getに対してNoSuchElementExceptionを返す。 SomeはisEmptyに対してfalseを、getに対して中身の値を返す。 Option("foo") //=> Option[java.lang.Strin
Best explanation for languages without null
Every so often when programmers are complaining about null errors/exceptions someone asks what we do without null. I have some basic idea of the coolness of option types, but I don't have the knowledge or languages skill to best express it. What is a great explanation of the following written in a way approachable to the average programmer that we could point that person towards? The undesirabilit
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http://beust.com/weblog/2010/07/28/why-scalas-option-and-haskells-maybe-types-wont-save-you-from-null/
Option
More Thoughts on Scala's Option Class