Update 2019-01-29: The feature set of ECMAScript 2019 is now final (source) and described in this blog post.

The proposal “String.prototype.matchAll” by Jordan Harband is currently at stage 3. This blog post explains how it works.

JavaScript never removes old features – new versions are always backward compatible. I wish we could clean it up, but staying compatible has too many benefits, as I’ll explain in this blog post.

The proposal “Numeric Separators” by Sam Goto and Rick Waldron lets us use _ as a separator in numeric literals. This blog post explains how that works.

This blog post explains patterns and techniques for external and internal iteration in ReasonML.

Functors are mappings from modules to modules. This blog post explains how they work and why they are useful.

This blog post examines how ReasonML’s records work.

In this blog post, we look at polymorphic variants, which are a more flexible version of normal variants. But that flexibility also makes them more complicated.

In this blog post, we look at two ReasonML data structures – lists and arrays:

Variant types (short: variants) are a data type supported by many functional programming languages. They are an important ingredient in ReasonML that is not available in C-style languages (C, C++, Java, C#, etc.). This blog post explains how they work.