%unimsg 0 profile/v0

-- The v0 conformance profile, expressed in unimsg rather than in prose.
--
-- Restrictions used to live as English in docs/12, which meant the only way
-- to enforce one was to hardcode a check. As a document a profile is
-- content-addressed, versionable, composable, and checkable by generic code.

profile @unimsg/v0 {
  doc "Conformance profile for unimsg v0."

  -- D10/F6: native float equality diverges from byte equality. -0.0 and 0.0
  -- are byte-distinct but compare equal; NaN and NaN are byte-identical but
  -- compare unequal. Banning float keys removes the divergence class rather
  -- than asking every implementer to handle it.
  --
  -- Bytes joined float on the same argument, having been allowed here for
  -- longer than anything implemented it. A byte-string key is unhashable in
  -- some hosts and indistinguishable from a text key in others, which is the
  -- same divergence wearing different clothes. Nothing in the repository ever
  -- wrote one; six implementations refused them in six different ways, and
  -- the profile said they were fine.
  keys {
    allow  [ :text, :int ]
    reject [ :float, :bytes ]
    reason "F6 — native float equality diverges from byte equality, and a bytes key diverges from a text key the same way"
  }

  -- Encoding-level rules. These cannot be checked from a decoded value; the
  -- validator needs the bytes.
  encoding {
    determinism    :required
    duplicate-keys :reject
  }

  limits {
    doc "WHAT max-depth COUNTS, settled 2026-09-02: containers of the value
         model. The document body is depth 0 and each map or sequence entered
         adds one, so a table row's cells are two below the table's parent —
         the sequence, then the row's map. Tags, annotations, qualifiers,
         decimals, references and extensions add nothing, because they are how
         a scalar is written and not what an author nests. This is the count
         `umsg profile` applies. A decoder's stack-safety cap is a different
         number, measured on the encoding, where a decimal is a tag around a
         two-element array; it must sit comfortably above this one, and the
         implementer's guide says how far."
    max-depth 500
  }
}