impossible wish: unravel complex or-and expressions

     (or (and b (weak-box-value b))
         (let ([e (make-cached-element style content key)])
           (hash-set! element-cache key (make-weak-box e))
           e))

could be much better communicated with:

     (cond
       [b (weak-box-value b)]
       [else
        (let ([e (make-cached-element style content key)])
          (hash-set! element-cache key (make-weak-box e))
          e)])

which then opens an opportunity for let-in-cond simplification rule to kick in.

It's an impossible wish because the two code are not quite semantically equivalent generally. They are equivalent here though, because (weak-box-value b) is guaranteed to be non #f.

The issue names no files, tests, or entry points. Start by locating the refactoring rules for complex or-and expressions and let-in-cond simplification, then determine how the engine can establish the non-#f guarantee. Done means the transformation applies only when the expressions are semantically equivalent and is covered by tests.