Structured object#

Structured object is the data surface that exposes named fields and values. Today, for filesystem markdown collections, it comes from parsed frontmatter metadata. The domain-model term is broader on purpose: future bases may provide rows, documents, or API resources directly as structured objects.

Terms#

TermMeaning
Structured objectA map-like representation of an item’s structured data.
FieldA key in the structured object. A field is an attribute; not every attribute is a field.
MetadataThe parsed markdown frontmatter shape used as the structured object today.
Schema directiveThe inline schema: key that opts an item into a named schema before validation.

Model#

In the current filesystem backend, the structured-object surface is Document.Meta from Markdown body text. It is normalized to map[string]any no matter whether the source frontmatter was YAML, TOML, or JSON.

Structured-object checks validate fields and schema-backed object shape. They are the right fit when a check needs to ask about named values: required fields, field type, field length, enum membership, uniqueness, sentence case, or JSON Schema validation.

The schema: directive is Katalyst metadata. It selects a configured schema for the item and is removed before the item is validated against that schema.

Invariants#

  1. Field checks read normalized metadata. They do not branch on YAML, TOML, or JSON syntax.
  2. A field is narrower than an attribute. Filenames and path segments are attributes, but they are not structured-object fields.
  3. Schema selection is separate from validation. The directive chooses the schema; the object check validates the resulting structured object.

See also#