Intentional variable shadowing, sorting floats, and other reflections on writing Rust: https://rcoh.me/posts/thoughts-on-rust-a-few-thousand-lines-in/
miniblog.
Related Posts
Emacs' support for OCaml is exceptionally good. Not only does tuareg-mode have a decent REPL integration, but it even has thorough 'pair' highlighting for keywords!
Even more impressively, merlin-eldoc understands scope and shadowing when highlighting symbols!
Some subtle shadowing gotchas in Rust: https://users.rust-lang.org/t/surprising-item-shadowing/3494 (fortunately the compiler warns you in this circumstance)

