'Grab another set of input tokens and convert them to an output string.'

def chunk(self):

    for (delta, c) in self.candidates(0):
        if (c in _l2u):
            self.pos += delta
            try:
                return unichr(_l2u[c])
            except NameError:
                return chr(_l2u[c])
        elif ((len(c) == 2) and (c[1] == 'i') and ((c[0], '\\i') in _l2u)):
            self.pos += delta
            try:
                return unichr(_l2u[(c[0], '\\i')])
            except NameError:
                return chr(_l2u[(c[0], '\\i')])
        elif ((len(c) == 1) and c[0].startswith('\\char') and c[0][5:].isdigit()):
            self.pos += delta
            try:
                return unichr(int(c[0][5:]))
            except NameError:
                return chr(int(c[0][5:]))
    self.pos += 1
    return self[(-1)]
