developer-sdk

#!/usr/bin/env python
# -*- coding:utf-8 -*-

class Parent(object):

	def __init__(self, name):
		self.name = name
		print('My name is {0}'.format(name))

	def show(self):

developer-sdk

object FuncThinking1 extends App {

  def firstIndexOfAny(input: String, searchChars: Seq[Char]): Option[Int] = {

    def indexedInput = (0 until input.length).zip(input)
    val result = for (pair <- indexedInput; char <- searchChars; if (char == pair._2))
      yield (pair._1)

    if (result.isEmpty)
      None

developer-sdk

import java.util.ArrayList;
import java.util.List;

public class PersonList {
    
    public String cleanNames(List<String> listOfNames) {
        StringBuilder builder = new StringBuilder();
        
        for(int i = 0; i < listOfNames.size(); i++) {
            if(listOfNames.get(i).length() > 1) {

developer-sdk

object FuncThinking2 extends App {
  val employees = List("james", "s", "kevin", "paul")
  
  val result1 = employees.filter(_.length > 1).map(_.capitalize).reduce(_ + "," + _)
  println(result1)

  // 동일한 결과, 최종 문자열 조인의 차이 
  val result2 = employees.filter(_.length > 1).map(_.capitalize).mkString(",")
  println(result2)
}

developer-sdk

import java.util.concurrent.TimeUnit.NANOSECONDS
def time[T](f: => T): T = {
    val start = System.nanoTime()
    val ret = f
    val end = System.nanoTime()
    // scalastyle:off println
    println(s"Time taken: ${NANOSECONDS.toMillis(end - start)} ms")
    // scalastyle:on println
    ret
}

developer-sdk

val employees = List("james", "s", "kevin", "paul")

// 서술형 프로그래밍 
val result1 = employees.filter(_.length > 1).map(_.capitalize).reduce(_ + "," + _)
// par을 추가하여 병령처리 
val result2 = employees.par.filter(_.length > 1).map(_.capitalize).reduce(_ + "," + _)

developer-sdk

// a 와 b를 더하는 함수를 반환 
def adder(a: Int) = (b: Int) => {
  a + b
}

// a의 값에 각각 5와 7을 바인딩, 함수가 해제하기 전까지 데이터를 저장 
def addFive = adder(5)
def addSeven = adder(7)

println(addFive(2))   // 7

developer-sdk

def modN(n: Int)(x: Int) = ((x % n) == 0)

// modN함수를 커링을 이용하여 n 값이 정해진 변수로 호출 
def modOne:Int => Boolean = modN(1)
def modTwo = modN(2) _

println(modOne(4))  // true
println(modTwo(4))  // true
println(modTwo(5))  // false

developer-sdk

object memoizeSample extends App {
  // 처리 시간 출력 
  import java.util.concurrent.TimeUnit.NANOSECONDS
  def time[T](f: => T): T = {
    val start = System.nanoTime()
    val ret = f
    val end = System.nanoTime()
    println(s"Time taken: ${NANOSECONDS.toNanos(end - start)} nonos")
    ret
  }

developer-sdk

package functional.stage1;

import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;

/**
 * 명령형 자연수 분류기
 * 
 * @author whitebeard-k