2. 创建Type Class A type class is an interface or API that represents some functionality we want to implement. In Cats a type class is represented by a trait with at least one type parameter. // The "serialize t
我fork 了 scala-with-cats 仓库,并添加了最后一章的笔记 https://github.com/IBAS0742/scala-with-cats 修改 这里大概对每一章的内容进行了概括,不一定对,权且看看 C1:主要讲隐式参数 C2:幺半群和半群,不同的计算顺序可以得到一样的计算结果,例如加操作 C3:算子,通过map的形式组合多个算子,使得执行一个系...
monoid在Cats中的定义为:trait Monoid[@sp(Int, Long, Float, Double) A] extends Any with Semigroup[A] { def empty: A def isEmpty(a: A)(implicit ev: Eq[A]): Boolean = ev.eqv(a, empty) override def combineN(a: A, n: Int): A = if (n < 0) throw new IllegalArgumentException...
This branch is4 commits ahead ofkwame998/scala-with-cats:master. Folders and files Name Last commit message Last commit date Latest commit Cannot retrieve latest commit at this time. History 5 Commits chapter01 first commit Nov 1, 2019
所以不需要去实现AbsIterator的抽象成员 trait RichIterator extends AbsIterator { // foreach的输入为一个函数f,函数f输入数据类型为泛型T,输出类型为Unit def foreach(f: T => Unit): Unit = while (hasNext) f(next()) } class RichStringIter extends StringIterator("Scala") with RichIterator val ...
class RichStringIter extends StringIterator("Scala") with RichIterator val richStringIter = new RichStringIter richStringIter foreach println } 1. 2. 3. 4. 5. 新的类RichStringIter有一个父类StringIterator和一个mixinRichIterator。如果是单一继承,我们将不会达到这样的灵活性。
For Cats & Scalaz. bizzabo/diff - Visually compare Scala data structures with out of the box support for arbitrary case classes. bizreach-inc/play2-hands-on - Play2 + Slick / ScalikeJDBCを使ってWebアプリケーションを作成するハンズオンです。 vinta/albedo - A recommender system for ...
scala语言的关键字往往多义,有很多常见的关键字是多义的。如_,在不同的词法上下文当中,会有如下含义:代表不同位置的参数、全部、除去、忽略 等等 。其他如var、va、 箭头符号 、with、class 组合关键字:case class、 this.type ,有些时候站在Java语言的角度,甚至是两个矛盾的关键字进行组合。如 abstract overwrit...
7-12 章读完了，中间还读了两本书，是 typelevel 的Essential Scala和Scala with Cats，读完这些书后...