Merge branch 'gleam-lang:main' into gleam-for-javascript-users

Author: nino

_data/sponsors.yml

@@ -658,6 +658,11 @@
   avatar: "https://avatars.githubusercontent.com/u/24900688?u=f55f5ef982cc7b992eadd7f58fa34dc7abd45233&v=4"
   tier: 2
   square_avatar: false
+- name: "Xetera"
+  url: "https://github.com/Xetera"
+  avatar: "https://avatars.githubusercontent.com/u/24978328?u=e4286d30bfd5917cc750729b877316610cd41c13&v=4"
+  tier: 1
+  square_avatar: false
 - name: "Zsombor Gasparin"
   url: "https://github.com/gasparinzsombor"
   avatar: "https://avatars.githubusercontent.com/u/25465322?u=18186bbf5e9df8274c5795f2d8359a06ebf0885c&v=4"

book-src/tour/custom-types.md

@@ -250,3 +250,25 @@ LoggedIn("Kim")
 guest,
 {logged_in, <<"Kim">>}.
 ```
+
+## JavaScript interop
+
+When compiling to JavaScript, each constructor becomes a class of the same name.
+Each of the generated JavaScript classes has a constructor with the same
+arguments as the original type constructor.
+
+```gleam
+// Gleam
+Guest
+LoggedIn("Kim")
+Cat(name: "Jinx", cuteness: 2002)
+```
+
+```javascript
+// JavaScript
+import { Guest, LoggedIn, Cat } from "my_module.mjs";
+
+new Guest();
+new LoggedIn("Kim");
+new Cat("Jinx", 2002);
+```