Here's a screenshot:

There are also other edge cases not handled properly, though I doubt anybody actually faces them, and so fixing them might not be worth it:

Code used in screenshots
-- This works.
a = 1 `bar` 2
-- This doesn't.
b = 1 `bar'` 2
-- The number and placement of primes doesn't matter.
c = 1 `b'ar` 2
d = 1 `b'a'r` 2
-- Bonus (these actually work!).
e = 1 `(+)` 2
f = 1 `clamp 2` 3 -- I know this is nonsense, but bear with it.