Scala has had monadic do-notation (called 'for-comprehensions') for a long time and OCaml has recently gained both monadic and applicative 'do notation' (called various things, but mostly 'let+ syntax'). Edit: Oh and F# has also had computation expressions for a long time.

It’s even nicer in Haskell because not only does do-notation make code look clean, await is a function, not an operator.

Want prefix await? Go for it!

    res <- await $ foo bar

Want postfix? You can have that too!

    res <- foo bar & await

Being “just a function” means it composes with everything else in the language, something the Rust languages designers have held in high regard when designing this.

(But I also fully appreciate the design constraints that prevent Rust from using “just a method” or ”just a macro”)