What It Is 😀

• Strongly typed functional programming language (JS of FP languages)
• Dialect of Ocaml that looks like JS
• Compiles to JS (BuckleScript), Node (BuckleScript), or  Native (Ocaml)
• Uses not 1, not 2, but 3 APIs: Reason/Ocaml/BuckleScript

What It's Not 😞

• Pure
• HKT or Ad Hoc Polymorphism
• Super duper functional algabraic expialidocious

Benefits  👍

• Looks like JS with the just right amount of FP
• Types are inferred
• ADT
• Fast compile times
• Bindings (node, express, react, jest, etc.)
• FFI
• Write once, run everywhere
• Macros
• Plain ole' JS escape hatch - desperate times call for desperate measures

Downsides 👎

• Small community
• Good but not great error messages
• No create-reason-react-app
• bs-platform build dependency
• API hell
• Data first? Data last? Make up your mind
• Did I mention BS?

Similarities 💩

• Objects
• Functions
• Arrays
• Strings
• let bindings
• Mutable values
• Boolean
• for/while loops
• if/else
• Promise
• Destructuring
• Exceptions

Differences 👨‍🎤

• Int/Floats
• Lists
• Records
• ADT/Variants
• Pipe/pipe first (|> / ->)
• Options (Maybes)
• Tuples
• Chars
• Global Modules
• Labeled/optional/as function arguments w/partial application
• Unused variable indicators

Code Time ⏰

https://bit.ly/reason-by-example

https://github.com/arecvlohe/reasonml-cheat-sheet

ReasonReact 🤯

• Everything you like about Reason in React
• Reminder: Go to ReasonReact in Browser

The End is Nigh 😄

Simon Game in ReasonReact