lengthy-list.py

#!/usr/bin/python

class T(object):
    def __init__(self, n=0, lists=None):
        self.lists = lists if lists is not None else []
        if lists is None:
            # lists contains normal lists and t's as well
            self.lists = []
        # cached length prefix
        self.n = n
        # iterator position
        self.i = 0

    @staticmethod
    def FromInt(n):
        return T(n=n)

    @staticmethod
    def FromList(l):
        return T(lists=[iter(l)])

    def __iter__(self):
        self.i = 0
        return self

    def next(self):
        if self.i < self.n:
            self.i += 1
            return True
        if len(self.lists) == 0:
            raise StopIteration
        for l in self.lists:
            l.next()

        self.n += 1
        self.i += 1
        return True

    def min(self, t):
        return T(lists=[iter(self), iter(t)])

    def __cmp__(self, t):
        l = iter(self)
        r = iter(t)
        rmore = lmore = True
        while (lmore and rmore):
            try:
                l.next()
            except StopIteration:
                lmore = False
            try:
                r.next()
            except StopIteration:
                rmore = False
        if not lmore and not rmore:
            return 0
        elif not lmore:
            return -1
        else:
            return 1