programming in scala

Java and Scala environment configuration in Linux Recently, I have been studying a project on "natural language processing". In this project, we need to use Spark for programming. The Spark kernel is developed by the Scala language. Therefore, before using Spark, We must configure Scala and Scala runs on the JVM. There

The neophyte ' s Guide to Scala part 12:type ClassesOver the past two weeks, we have discussed some functional programming techniques that keep us dry and flexible, in particular function combinations, the application of partial functions, and currying. Next, I'll continue to discuss how to make your code as flexible as possible.However, this time we will not discuss how to use a function as a class object for this purpose, but instead use the type sy

Quick StartThis article describes how to use scala, java, and python to compile a spark click Mode Program. First, you only need to successfully build Spark on a machine. Practice: Enter the Spark root directory and enter the command: $ sbt/sbt package(Because of the Great Firewall of tianchao, the mainland China cannot succeed, unless you can smoothly flip the wall). If you do not want to climb the wall, you can download the pre-compiled Spark, spark

1. PreparationThis article focuses on how to build the Spark 2.11 stand-alone development environment in Ubuntu 16.04, which is divided into 3 parts: JDK installation, Scala installation, and spark installation. JDK 1.8:jdk-8u171-linux-x64.tar.gz Scala 11.12:scala 2.11.12 Spark 2.2.1:spark-2.2.1-bin-hadoop2.7.tgz It is important to note that

=NewHeap1to Kforeach(I=>heap.Insert(Array(i))) K+1to array.length-1 foreach(i=>{ while(Heap.GetSize>Ten) {heap.Deletemin}if(Array(i) >heap.Getmin) {heap.DeleteminHeap.Insert(Array(i))}}) heap.Print}And again, Heap how it's achieved.The use of Scala often comes across the option of changing and not changing variables, which is a problem.There for is also the derivation formula, which is actually map flatMap equal to the grammatical sugar.Code:classHeap

Apply: When you pass one or more arguments to a variable (object) in parentheses, Scala turns it into a call to the Apply methodVal Array=array (1,2,3,4,5,6)Array (0), the operation of the first element of the array is converted to the array.apply (0) operation, which also explains why the Scala array value is not enclosed in parentheses, because it is also a method call.Anyobject ("Key1") will be converted

Scala is a static type of scripting language built on the JVM, and scripting languages always have some conventions to enhance flexibility. Flexibility allows the person who has mastered it to be a duck in the hand, as well as a beginner. For example, Scala has such a convention in the method invocation for the DSL to mate: In the case where the receiver of the method call is defined, the point and parenthe

VIM Tools Vim is a very useful tool, a small and capable code editor, no wonder many people are regarded as "The God of the editor." IDE Write code, in addition to the code debugging function, other functions vim can be implemented, and Vim does not occupy a lot of memory, so, write code using VIM is fully "enough." Here's a look at the online configuration for developing a code environment with vim+ Scala 1 Ctags Installation Download Ctags-x.x.tar

===========================================Original link: Scala to MongoDB additions and deletions to the operation reproduced please specify the source! ===========================================Environment dependent: jdk1.8, Scala 2.12, IdeaMongoDB driver:3.1.1. Note that the MONGO for Scala driver involves multiple jars (such as) and relies on Mongo-java-dr

checksumaccumulator { private var sum = 0 = { + = b } = { return ~ (sum 0xFF) + 1 }}Any parameters passed to the method can be used inside the method. An important feature of the method parameters in Scala is that they are all Val, not var. If you want to reassign a parameter to a method, the result is a compilation failure:Scala> def Add (b:byte): Unit = { | // compile however, because B is Val | sum + = b| } a membe

Description, since Spark was written in Scala. Therefore, it is best to use Scala whether you are looking at the source code or writing spark-related codes. Then, as a programmer, the first thing to do is to sharpen the sword in hand. That's creating a code environment for writing Scala. Here because I am personally familiar with eclipse (although I think he is a

Background Notes Recent research spark need Scala to prepare a Scala environment for documenting the configuration notes.The Scala language is based on the Java language, so you have to install the JDK first. Experimental Environment: Win7 under VMware Virtual machine operating system: CentOS 6.5 x64 java:jdk-8u161-linux-x64.tar.gz scala:scala-2.12.4.tgz Install

Array/ ing/tuples I. Array 1. Fixed Length Array Two forms of declaring an array: Declare the Val array name of the specified length = new array [type] (array length) 　　 Provides an array of initial values without the new keyword. 　　 Scala declares an array with an array class name and uses () to specify the length or provide an initial value sequence. In JVM, scala array is implemented in Java array

Scala List class Faq:how do I create a list in Scala?You can create a Scala List in several different ways, including these approaches: Lisp style Java style Using the List class range method Using the List class fill method Using the List class tabulate method In this Scala List tutorial,

Scala REPLRes1,res2, ... res5 and so on, respectively, indicate the output result. If the result of a computed output is identified as Res2, then the res2 can be used directly in subsequent calls.Cases:Scala Worksheek in the Scala IDEThis is a very useful feature provided by the Scala IDE. Its function is the equivalent of Sc