You are currently looking at the v6.0 - v8.2 docs (Reason v3.6 syntax edition). You can find the latest manual page here.
(These docs are equivalent to the old BuckleScript docs before the ReScript rebrand)
Browser Support & Polyfills
For old browsers, you also need to polyfill TypedArray. The following standard library functions require it:
If you don't use these functions, you're fine. Otherwise, it'll be a runtime failure.