def _followups(self, nonterm):
"""Return the set of token types that could follow the given
nonterminal."""
res = {}
for nonterm2, symb in self._parse_table.keys():
if nonterm == nonterm2:
set_add(res, symb)
return seq_sorted([Token.type_description(key) for key in res.keys()])
def init_builtins(self):
"Initialize a global context with types for all the builtins."
for b in gbs_builtins.get_builtins():
bname, b = b.name(), b.underlying_construct()
set_add(self.ribs[0], b.name())
self.global_context[b.name()] = b.gbstype()
for type_name, gbs_type in gbs_type.BasicTypes.items():
self.global_context[type_name] = gbs_type()
def _add_var(self, token, new_type=None):
"""Add a variable to the context with the given type, checking
that it is consistent with the types it might already have."""
if new_type is None: # fresh
new_type = gbs_type.GbsTypeVar()
varname = token.value
if varname in self.ribs[-1]:
old_type = self.context[varname]
gbs_type.unify(new_type, old_type)
else:
self.context[varname] = new_type
set_add(self.ribs[-1], varname)
return new_type
