Many programming languages use braces, parentheses and brackets to convey structure.

Javascript and C do it this way:

  if (foo) {
    bar(42, zonk());
  }

Guile/Clojure/etc do it this way:

  (if foo
   (bar 42 (zonk)))

If you didn't have the separators, programs would be harder to interpret for compilers and human readers, as it's harder to tell what the programmer meant from just

  if foo 
   bar 42 zonk