(diagnostic
  (schema slovo.diagnostic)
  (version 1)
  (severity error)
  (code MalformedWhileForm)
  (message "`while` must have a condition")
  (file "<fixture>")
  (span
    (bytes 37 44)
    (range 5 3 5 10)
  )
  (hint "use `(while condition body...)`")
)