Introduction topic

Despite the stick YAML gets, under all that complexity, is a highly configurable data format that you can bend to your will with the right tools. Based on the process model, the parser allows you to access data from the YAML string provided in two ways:

1. As a built-in Dart type
2. As a YamlSourceNode.

Built-in Dart types

YAML supports various types out of the box which, by default, are built-in Dart types. These types include:

The parser deterimines these YAML types automatically as required by the spec. All tags, aliases, anchors and styles are stripped and objects returned as any of the Dart types mentioned above. The types are not wrapped in any intermediate class. Any unsupported scalar type will always be returned as a String.

YamlSourceNode

Alternatively, the parser can also emit a YamlSourceNode that:

1. Is immutable.
2. Has span information about the node in the source string or byte source.
3. Persists its resolved/default tag assigned to it by the parser.
4. Preserves its own anchor/alias information. Usually, every AliasNode holds a reference and anchor name to the actual node it referenced as an anchor. The same node also has the same anchor name. You need not worry about any node mismatch.
5. Preserves the integer radix for a Scalar resolved as int.

It has 3 distinct subtypes that cannot be subclassed:

• Mapping - corresponds to a Dart Map
• Sequence - corresponds to a Dart List
• Scalar - represents any type that is not a map or list.

Additional Features

• A spec-compliant expressive API to declare tags and other YAML properties.
• Custom resolvers for custom tag shorthands.
• CompactNode interface that allows custom objects to declare custom properties
• Dumper functions that can dump any object to YAML.