Reason

SBJS

@jamesdabbs

React

&

Reasons for Reason

• TypeScript

• Elm

• ReasonML

• JavaScript

Reasons for Reason

• Strong type system

• Good, ergonomic type inference

• Sound types

• Small, easy to reason about

If it compiles

Reasons for Reason

Reasons for Reason

• Native support is slated

• Tooling is surprisingly good

• Designed for production use

• Designed for adoptability

• Reason

• BuckleScript

• ReasonReact

Code Samples

• RawboNES

  • Cpu.re

• EpiderNES

  • App.re - state handling

  • Nes.re - component with routing

  • Util.re - JS interop examples

Findings

(so far)

• Compile and iteration time is amazing

• The type system is at a nice sweet spot

  • Inference generally just works

  • If it compiles it runs

  • If it doesn't compile, it caught a bug

• Compiled output is readable, small, and structured similarly to the source

Findings

(so far)

• Get to use OCaml, Reason, and JS ecosystems

• Often have to keep all of those layers in your head simultaneously

Findings

(so far)

• `optional` chaining requires more boilerplate than I'd like

• Impossible to have `undefined is not a function` errors

Findings

(so far)

• Some things that require a library in JS are just language features

  • Routing ⇒ pattern matching

  • Component composition

  • State management

Findings

(so far)

• Some things are irritating

  • The autoformatter is fiddly

    • Comments

    • Test blocks

  • JSX requires boilerplate

    • <p>{React.string(string_of_int(5)}</p>

Findings

(so far)

• Compile step has benefits

  • Optimizations

  • Dead function and module removal

  • Amenable to tree-shaking

  • Produces engine-friendly JS code

• I've found it promising

• Planning for one more experiment before pushing for adoption at work

• Try it out!