Annotation class abstract

Provides reflective access to annotations applied to declarations.

This interface abstracts annotation metadata access, allowing inspection of:

• Annotation types and signatures
• Field values (both user-provided and defaults)
• Protection domains
• Actual annotation instances

{@template annotation_interface_features}

Key Features

• Type-safe field value access
• Distinction between default and user-provided values
• Protection domain awareness
• Full metadata inspection
• Instance retrieval when available

Implementation Notes

Concrete implementations typically wrap platform-specific reflection objects while providing this uniform interface.

Example Usage

// Get annotation from a reflected method
final annotation = method.getAnnotation<JsonSerializable>();

// Inspect field values
final explicitNulls = annotation?.getFieldValueAs<bool>('explicitToNull');
final fieldRename = annotation?.getFieldValue('fieldRename');

// Check value sources
if (annotation?.hasUserProvidedValue('constructor')) {
  print('Custom constructor specified');
}

// Get all configured values
final allValues = annotation?.getAllFieldValues();

{@endtemplate}