(diagnostic
  (schema slovo.diagnostic)
  (version 1)
  (severity error)
  (code InvalidI64Literal)
  (message "i64 literal must use signed decimal digits before the `i64` suffix")
  (file "<fixture>")
  (span
    (bytes 37 41)
    (range 5 3 5 7)
  )
  (expected "signed decimal digits followed by `i64`")
  (found "-i64")
  (hint "use forms like `42i64` or `-7i64`; other i64 literal forms remain deferred")
)