def addtoken(self, type, value, context):
        """Add a token; return True iff this is the end of the program."""
        # Map from token to label
        ilabel = self.classify(type, value, context)
        # Loop until the token is shifted; may raise exceptions
        while True:
            dfa, state, node = self.stack[-1]
            states, first = dfa
            arcs = states[state]
            # Look for a state with this label
            for i, newstate in arcs:
                t, v = self.grammar.labels[i]
                if ilabel == i:
                    # Look it up in the list of labels
                    assert t < 256
                    # Shift a token; we're done with it
                    self.shift(type, value, newstate, context)
                    # Pop while we are in an accept-only state
                    state = newstate
                    while states[state] == [(0, state)]:
                        self.pop()
                        if not self.stack:
                            # Done parsing!
                            return True
                        dfa, state, node = self.stack[-1]
                        states, first = dfa
                    # Done with this token
                    return False
                elif t >= 256:
                    # See if it's a symbol and if we're in its first set
                    itsdfa = self.grammar.dfas[t]
                    itsstates, itsfirst = itsdfa
                    if ilabel in itsfirst:
                        # Push a symbol
                        self.push(t, self.grammar.dfas[t], newstate, context)
                        break # To continue the outer while loop
            else:
                if arcs in (0, state):
                    # An accepting state, pop it and try something else
                    self.pop()
                    if not self.stack:
                        # Done parsing, but another token is input
                        raise ParseError("too much input",
                                         type, value, context)
                else:
                    # No success finding a transition
                    raise ParseError("bad input", type, value, context)
dataset/ETHPy150Open anandology/pyjamas/pgen/lib2to3/pgen2/parse.py/Parser.addtoken/swapped operands of `in`