MoustafaAMahmoud

Notes from Coursera course 'Functional Programming Principles in Scala":
https://class.coursera.org/progfun-004

✔ Week 1: Functions & Evaluations @done (14-05-01 17:20)

    ✔ Lecture 1.1 - Programming Paradigms (14:32) @done (14-04-27 17:54)

        3 paradigms: imperative, functional, logic
        OO: orthogonal
        imperative:

MoustafaAMahmoud

This cheat sheet originated from the forum, credits to Laurent Poulain. We copied it and changed or added a few things.

Evaluation Rules

• Call by value: evaluates the function arguments before calling the function
• Call by name: evaluates the function first, and then evaluates the arguments if need be

    def example = 2      // evaluated when called
    val example = 2      // evaluated immediately

MoustafaAMahmoud

package test

import org.apache.spark.rdd.RDD
import org.apache.spark.sql.SparkSession

import scala.collection.mutable

class DisjointSet() extends Serializable {

  private val parentMap = mutable.Map[Int, Int]()

MoustafaAMahmoud

Week 1

lecture "Recap: Functions and Pattern Matching"

recursive function + case classes + pattern matching: example JSON printer (Scala -> JSON) pattern matching in Scala SDK: PartialFunction is a Trait with def isDefinedAt(x: A): Boolean

lecture "Recap: Collections"

• Iterable (base class)
  • Seq

MoustafaAMahmoud

import java.io.InputStream

import org.apache.spark.sql.execution.datasources.jdbc.JdbcUtils
import org.apache.spark.sql.{ DataFrame, Row }

import org.postgresql.copy.CopyManager
import org.postgresql.core.BaseConnection

val jdbcUrl = s"jdbc:postgresql://..." // db credentials elided
val connectionProperties = {

MoustafaAMahmoud

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Eric Pederson

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