Spark Code Style Guide

Please follow the style of the existing codebase. Apache Spark follows the official Scala style guide, but with the following changes:

Line Length

Limit lines to 100 characters.

Imports

Always import packages using absolute paths (e.g. scala.util.Random) instead of relative ones (e.g. util.Random).

In addition, sort imports in the following order:

• java.* and javax.*
• scala.*
• Third-party libraries (org.*, com.*, etc)
• Project classes (org.apache.spark.*)

Infix Methods

Don't use infix notation for methods that aren't operators. For example, instead of list map func, use list.map(func), or instead of string contains "foo", use string.contains("foo"). This is to improve familiarity to developers coming from other languages.

Curly Braces

Put curly braces even around one-line if, else or loop statements:

// Correct:
if (true) {
  println("Wow!")
}

// Wrong:
if (true)
  println("Wow!")