Class Grammar

Known Subclasses:

CGrammar

the grammar class:
a grammar consists of
  - a LexDict lexical dictionary;
  - a deterministic FSMachine;
  - a Rulelist
and optionally a dictionary that maps Rulenames
to Rulelist indices (used for dumping and externally)

this method associates rules to names using a
RuleNameDict dictionary which maps names to rule indices.
after invocation
  self.RuleNameToIndex[ name ] gives the index
    in self.RuleL for the rule associated with name, and
  self.RuleL[index].Name gives the name associated
    with the rule self.RuleL[index]

bind a terminal to a regular expression and interp function
in the lexical dictionary (convenience)

if the Name dictionary has been initialized
this method will (re)bind a reduction function to
a rule associated with Rulename

this may be silly, but to save some space in construction
a token dictionary may be used that facilitates sharing of
token representations.  This method either initializes
the dictionary or disposes of it if it exists

parse a string using the grammar, return result and context

parse a string using the grammar, but only return
the result of the last reduction, without the context

look for default bindings

setting case sensitivity: must happen before keyword installation
in LexD.