### New features

Add support for grammar dialects.

Add support for external specializers.

Stacks now have a `parser` accessor that gets you the active parser instance.

### Breaking changes

No longer list internal properties in the type definitions.

Follow changes in the serialized parser format.

The way different tokenizers are combined is now slightly different. The first one to return a token wins, even if that token has no actions in the current state. The old behavior, where further tokenizers are tried until actions are found, can be enabled for a given tokenizer by setting its `fallback` flag.