An action is either an array of actions... ... or a case statement with guards... ... or a basic action with a token value.
map from string to ILanguageAction
go back n characters in the stream
array of actions for each parenthesized match group
log a message to the browser console window
the next state to push, or "@push", "@pop", "@popall"
switch to embedded language (useing the mimetype) or get out using "@pop"
switch to this state
token class (ie. css class) (or "@brackets" or "@rematch")