jtd.cddl

; root-schema is identical to schema, but additionally allows for
; definitions.
;
; definitions are prohibited from appearing on non-root schemas.
root-schema = {
  ? definitions: { * tstr => { schema}},
  schema,
}

; schema is the main CDDL rule defining a JTD schema.
;
; All JTD schemas are JSON objects taking on one of eight forms
; listed here.
schema = (
  ref //
  type //
  enum //
  elements //
  properties //
  values //
  discriminator //
  empty //
)

; shared is a CDDL rule containing properties that all eight schema
; forms share.
shared = (
  ? metadata: { * tstr => any },
  ? nullable: bool,
)

; empty describes the "empty" schema form.
empty = shared

; ref describes the "ref" schema form.
;
; There are additional constraints on this form that cannot be
; expressed in CDDL. Section 2.2.2 describes these additional
; constraints in detail.
ref = ( ref: tstr, shared )

; type describes the "type" schema form.
type = (
  type: "boolean"
    / "float32"
    / "float64"
    / "int8"
    / "uint8"
    / "int16"
    / "uint16"
    / "int32"
    / "uint32"
    / "string"
    / "timestamp",
  shared,
)

; enum describes the "enum" schema form.
;
; There are additional constraints on this form that cannot be
; expressed in CDDL. Section 2.2.4 describes these additional
; constraints in detail.
enum = ( enum: [+ tstr], shared )

; elements describes the "elements" schema form.
elements = ( elements: { schema }, shared )

; properties describes the "properties" schema form.
;
; This CDDL rule is defined so that a schema of the "properties" form
; may omit a member named "properties" or a member named
; "optionalProperties", but not both.
;
; There are additional constraints on this form that cannot be
; expressed in CDDL. Section 2.2.6 describes these additional
; constraints in detail.
properties = (with-properties // with-optional-properties)

with-properties = (
  properties: { * tstr => { schema }},
  ? optionalProperties: { * tstr => { schema }},
  ? additionalProperties: bool,
  shared,
)

with-optional-properties = (
  ? properties: { * tstr => { schema }},
  optionalProperties: { * tstr => { schema }},
  ? additionalProperties: bool,
  shared,
)

; values describes the "values" schema form.
values = ( values: { schema }, shared )

; discriminator describes the "discriminator" schema form.
;
; There are additional constraints on this form that cannot be
; expressed in CDDL. Section 2.2.8 describes these additional
; constraints in detail.
discriminator = (
  discriminator: tstr,

  ; Note well: this rule is defined in terms of the "properties"
  ; CDDL rule, not the "schema" CDDL rule.
  mapping: { * tstr => { properties } }
  shared,
)