我需要将两个函数作为参数传递给scala函数.然后,该函数应对它们进行评估并从中获取一个数字,然后对其进行操作.此数字可以是Int,Double或任何其他数字类型.无论它使用什么类型,我都希望该功能能够正常工作.
下面的例子解释了这个问题.
import Numeric.Implicits._
class Arithmetic[T : Numeric](val A: Connector[T], val B: Connector[T]) {
val sum = new Connector({ A.value + B.value })
}
class Constant[T](var x: T) {
val value = new Connector({ x })
}
class Connector[T](f: => T) {
def value: T = f
override def toString = value.toString()
}
object Main extends App{
val n1 = new Constant(1)
// works
val n5 = new Constant(5)
val a = new Arithmetic( n1.value, n5.value )
println(a.sum)
// no …Run Code Online (Sandbox Code Playgroud) Koding是一个协作编程环境,它为多个用户创建一个虚拟机来协作进行软件开发.他们使用Linux Containers来虚拟化机器.我无法在其上安装docker:
tiagoboldt@vm-2:~$ sudo docker build -t mongo .
[sudo] password for tiagoboldt:
Uploading context 645.1 kB
Uploading context
Step 0 : FROM ubuntu:latest
Pulling repository ubuntu
9cd978db300e: Error pulling image (latest) from ubuntu, endpoint: https://cdn-registry-1.docker.io/v1/, Driver aufs failed to get image rootfs 6170bb7b0ad1003a827e4dc5253ba49f6719599eac485db51eaafd507c13c311:
9cd978db300e: Error pulling image (latest) from ubuntu, Driver aufs failed to get image rootfs 6170bb7b0ad1003a827e4dc5253ba49f6719599eac485db51eaafd507c13c311: permission denied
6170bb7b0ad1: Error downloading dependent layers
2014/02/28 03:32:55 build: pull: Could not find repository on any of the indexed …Run Code Online (Sandbox Code Playgroud) 我使用以下代码遇到jquery和selectors问题:
<div id="test"></div>
console.log($('#test'));
Run Code Online (Sandbox Code Playgroud)
这总是返回一个列表,[<div id=?"test">?</div>?]而不是单个元素.
这导致总是必须$('#test')[0]为每个操作而不是仅写$('#test').有什么想法吗?
问候