You're right in that even Scheme, which evolved with teaching in mind, has gotchas. However, the Racket folks made "student languages" that specifically exclud

You're right in that even Scheme, which evolved with teaching in mind, has gotchas. However, the Racket folks made "student languages" that specifically exclude gotchas, so DrRacket is as close as a student can get to a gotcha-free environment.