class Syntax::Tokenizer

to the chunk.
After the new group is started, if +data+ is non-nil it will be appended

contents will be yielded to the client as a token, and then cleared.
group is created and the current chunk is not empty, the chunk's
as the group being requested, a new group will not be created. If a new
Request that a new group be started. If the current group is the same

def start_group( gr, data=nil )
  flush_chunk if gr != @group
  @group = gr
  @chunk << data if data
end