ReasonML Quick Start Guide

List

Reason lists are as follows:

• Homogeneous
• Immutable
• Fast at prepending and accessing the head of the list

They look like this:

let list = ["first", "second", "third"];

The head of the list, in this case, is "first". By now, we've seen that it's not difficult to work with immutable data structures. Instead of mutation, we create updated copies.

When working with lists, we can't use JavaScript bindings directly, since lists do not exist in JavaScript as a primitive data structure. However, we can convert lists to arrays and vice versa:

/* Belt standard library */let list = ["first", "second", "third"];let array = Belt.List.toArray(list);let array = [|"first", "second", "third"|];let list = Belt.List.fromArray(array);/* Reason standard ...