Type class-Typeclass-泛型基础上的二次抽象---随意多态
对泛型的类型添加约束，从而使泛型类型的变量具有某种通用操作。
再使用这些操作，参与到其它操作中。
In computer science, a type class is a type system construct that supports ad hoc polymorphism. This is achieved by adding constraints to type variables in parametrically polymorphic types. Such a constraint typically involves a type class T and a type variable a, and means that a can only be instantiated to a type whose members support the overloaded operations associated with T.
The programmer defines a type class by specifying a set of function or constant names, together with their respective types, that must exist for every type that belongs to the class. In Haskell, types can be parameterized; a type class Eq intended to contain types that admit equality would be declared in the following way:
-
class Eq a where
(==) :: a -> a -> Bool
(/=) :: a -> a -> Bool
最新文章
- mongo DB for C#
- 几个常用的Linux命令
- [Repost]Events and Signals in PyQt4
- 误打误撞写了段能让电脑奔溃的JS代码，但是自己不知道为什么，高手看到可以解答下吗？
- Rstudio使用记录
- 纯JS省市区三级联动
- hadoop 补充（转）
- What's the difference between all the Selection Segues
- 帝国cms文章内容tags关键词设置调用方法以及tags静态化
- SpringMVC框架学习笔记（4）——结果跳转方式
- 在Winform开发中使用Grid++报表
- Unable to find header files
- 每日算法之递推排序(P1866 编号)
- K8S学习笔记之Kubernetes数据持久化方案
- 剑指offer（61）序列化二叉树
- Under the same directory(folder) copy or rename with the different extension name
- python监控服务器的主备模式
- 05_ssm基础(二)之mybatis优化
- 我们为什么要使用Spring Cloud？简介
- <OFFER05> 05_ReplaceSpaces