Recently, my team started to use Elasticsearch. My coworker Sahan gave an sharing section to help all team members get started w/ Elasticsearch. This presentation aims to continue on that sharing.

Option is a commonly-used data type in Scala. It's call Maybe in Haskell and Optional in Swift. Option is also closely related the concept Monad.

Functional programming paradigm discourages the use of for/while loop and advocates other approaches to accomplish similar computation. This sharing section focuses on what these other approaches are.

This slide summarizes a few principles that Functional Program encourages. It explains what these principles are, the benefits and when to make an exception (not following the principle).