As you can see from the expression calculator
example, the grammar definition language of JS/CC consists of two parts: the token definition part and the
grammar part, which defines the language's grammar using a Backus-Naur-Form-styled meta-language. The two parts are
separated by a ## symbol, which could be seen as a "separating line" between both parts.
Some things in the current version of the JS/CC grammar definition language are a little bit nasty and need to be
reworked in the future — like this ## separator…