Format Metadata

Core fields handle shared source detail. Format modules expose constants for parser-specific details that still matter for inspection or round-tripping.

Common Core Fields

ConfigNode.comment() Leading, inline, and trailing comments attached to the value.

ConfigNode.decorations() Key comments, scalar style, collection style, source locations, and string attributes.

ConfigNode.metadata() Backend-specific values that are useful for round-tripping or inspection.

Core Metadata

Constant	Key	Meaning
`ConfigMetadataKeys.RAW_VALUE`	`core.rawValue`	Original backend value when preserving it is useful.

YAML

Constant	Key	Meaning
`YamlMetadataKeys.TAG`	`yaml.tag`	YAML tag for the value node.
`YamlMetadataKeys.ANCHOR`	`yaml.anchor`	YAML anchor name.
`YamlMetadataKeys.KEY_TAG`	`yaml.key.tag`	YAML tag for a key node.
`YamlMetadataKeys.SCALAR_RAW`	`yaml.scalar.raw`	Raw scalar text, such as `0x10`.

YAML also maps key comments, scalar style, collection style, key location, and value location into ConfigNodeDecorations.

Properties

Constant	Key	Meaning
`PropertiesMetadataKeys.SEPARATOR`	`properties.separator`	Separator used between key and value.
`PropertiesMetadataKeys.SINGLE_LINE`	`properties.singleLine`	Whether the value was written on a single logical line.
`PropertiesMetadataKeys.BLANK_LINES_BEFORE`	`properties.blankLinesBefore`	Blank lines before the property.

Repeated keys are represented as list nodes. Dotted keys are represented as paths.

JSON, JSONC, and JSON5

Constant	Key	Meaning
`JsonMetadataKeys.NUMBER_RADIX`	`json5.number.radix`	Numeric radix style exposed by the JSON5 backend.

The JSON module maps number radix into ConfigScalarStyle.BINARY, OCTAL, DECIMAL, or HEX where available.

HOCON

Constant	Key	Meaning
`HoconMetadataKeys.ORIGIN_DESCRIPTION`	`hocon.origin.description`	Origin details from Lightbend Config.
`HoconMetadataKeys.RENDERED`	`hocon.rendered`	Rendered source fragment retained from the backend.

HOCON origin comments are mapped into ConfigComment.

TOML

The TOML backend maps entry comments through ConfigComment and table-like structures through ConfigCollectionStyle.TABLE. It uses Night Config’s commented config model for parser and writer behavior.

Rule of Thumb

Use core fields for behavior that should work across formats. Use metadata constants only for format-specific behavior.