I’ve just released what I believe is a production-ready version of my library, es6_maps.

es6_maps hacks into the Elixir compiler to enable EcmaScript6-like shorthand map usage that you might know from JavaScript or Rust:

iex> foo = 1
iex> %{hello, bar} = %{foo, hello: "world", bar: 2}
%{foo: 1, hello: "world", bar: 2}
iex> hello
"world"

There’s already a popular library doing a similar thing, shorter_maps, that doesn’t need any module-replacing shenanigans in order to do its thing. The motivation for implementing es6_maps instead of using shorter_maps was that:

1. I do firmly believe this is a good language feature and a very natural extension of map literals syntax;
2. at the same time, being a language feature it should be simple - es6_maps works only with atom keys and has no extra features over the key expansion.

Point 1 is additionally reinforced by how easy it was to introduce to the compiler - I’m injecting just 9 lines of simple code, while parser and lexer already accept short-form maps without modifications.

The library also includes a Mix task for jumping all-in to shorthand map forms - as well as reverting all of the shorthand literals back into expanded ones in case you’d like to remove the dependency.

GitHub: GitHub - kzemek/es6_maps: `%{foo, bar: 1}` — ES6-like shorthand syntax for Elixir maps and structs
Hex: es6_maps | Hex
HexDocs: es6_maps v1.0.1 — Documentation