=> has several meanings in Scala, all related to its mathematical meaning as implication. 1. In a value, it introduces a function literal, or lambda. e.g. the bit inside the curly braces inList(1,2,3).map { (x: Int) => x * 2 } 2. In a type, with sym…
1.++[B] 在A元素后面追加B元素 scala> val a = List(1) a: List[Int] = List(1) scala> val b = List(2) b: List[Int] = List(2) scala> val c = a ++ b c: List[Int] = List(1, 2) scala> val d = List('a') d: List[Char] = List(a) scala> val e = c ++ d e: List…
1 What is Chisel? Chisel(Constructing Hardware In a Scala Embedded Language)是一种嵌入在高级编程语言Scala的硬件构建语言. Chisel是由伯克利大学发布的一种开源硬件构建语言,建立在Scala语言之上,是Scala特定领域语言的一个应用,具有高度参数化的生成器(highly parameterized generators),可以支持高级硬件设计. Chisel实际上只是一些特殊的类定义,预定义对象的集合…
占位符的用途颇多,先介绍几种常用的用法 1.作为"通配符",类似Java中的*.如import scala.math._2.:_*作为一个整体,告诉编译器你希望将某个参数当作参数序列处理!例如val s = sum(1 to 5:_*)就是将1 to 5当作参数序列处理.3.指代一个集合中的每个元素.例如我们要在一个Array a中筛出偶数,并乘以2,可以用以下办法:a.filter(_%2==0).map(2*_).又如要对缓冲数组ArrayBuffer b排序,可以这样:val b…
一.函数的源码 /** * Simplified version of combineByKeyWithClassTag that hash-partitions the resulting RDD using the * existing partitioner/parallelism level. This method is here for backward compatibility. It * does not provide combiner classtag informatio…