The TokenTransformDispatcher now actually implements an asynchronous, phased
token transformation framework as described in
https://www.mediawiki.org/wiki/Future/Parser_development/Token_stream_transformations.
Additionally, the parser pipeline is now mostly held together using events.
The tokenizer still emits a lame single events with all tokens, as block-level
emission failed with scoping issues specific to the PEGJS parser generator.
All stages clean up when receiving the end tokens, so that the full pipeline
can be used for repeated parsing.
The QuoteTransformer is not yet 100% fixed to work with the new interface, and
the Cite extension is disabled for now pending adaptation. Bold-italic related
tests are failing currently.
This required a few further additions to the TokenTransformDispatcher. In
particular, there is now an 'any' token match whose callbacks are executed
before more specific callbacks. This is used by the Cite extension to eat all
tokens between ref and /ref tags. This need is very common, so should be
broken out to an intermediate layer in the future.
In general, the requirements for the TokenTransformDispatcher API are now
clearer, and the API should likely be cleaned up / simplified.
token stream. This is the first token transformation exercising the
TokenTransformer class as its dispatcher. Template expansions, wiki link
formatting, tag sanitation and extensions should be able to use the same
dispatcher by registering for specific token types.
The parser performance is very slightly improved as the token stream is only
traversed once.
