"""A more or less complete user-defined wrapper around list objects."""

import collections

class UserList(collections.MutableSequence):

    def __init__(self, initlist=None):

        self.data = []

        if initlist is not None:

            # XXX should this accept an arbitrary sequence?

            if type(initlist) == type(self.data):

                self.data[:] = initlist

            elif isinstance(initlist, UserList):

                self.data[:] = initlist.data[:]

            else:

                self.data = list(initlist)

    def __repr__(self): return repr(self.data)

    def __lt__(self, other): return self.data <  self.__cast(other)

    def __le__(self, other): return self.data <= self.__cast(other)

    def __eq__(self, other): return self.data == self.__cast(other)

    def __ne__(self, other): return self.data != self.__cast(other)

    def __gt__(self, other): return self.data >  self.__cast(other)

    def __ge__(self, other): return self.data >= self.__cast(other)

    def __cast(self, other):

        if isinstance(other, UserList): return other.data

        else: return other

    def __cmp__(self, other):

        return cmp(self.data, self.__cast(other))

    __hash__ = None # Mutable sequence, so not hashable

    def __contains__(self, item): return item in self.data

    def __len__(self): return len(self.data)

    def __getitem__(self, i): return self.data[i]

    def __setitem__(self, i, item): self.data[i] = item

    def __delitem__(self, i): del self.data[i]

    def __getslice__(self, i, j):

        i = max(i, 0); j = max(j, 0)

        return self.__class__(self.data[i:j])

    def __setslice__(self, i, j, other):

        i = max(i, 0); j = max(j, 0)

        if isinstance(other, UserList):

            self.data[i:j] = other.data

        elif isinstance(other, type(self.data)):

            self.data[i:j] = other

        else:

            self.data[i:j] = list(other)

    def __delslice__(self, i, j):

        i = max(i, 0); j = max(j, 0)

        del self.data[i:j]

    def __add__(self, other):

        if isinstance(other, UserList):

            return self.__class__(self.data + other.data)

        elif isinstance(other, type(self.data)):

            return self.__class__(self.data + other)

        else:

            return self.__class__(self.data + list(other))

    def __radd__(self, other):

        if isinstance(other, UserList):

            return self.__class__(other.data + self.data)

        elif isinstance(other, type(self.data)):

            return self.__class__(other + self.data)

        else:

            return self.__class__(list(other) + self.data)

    def __iadd__(self, other):

        if isinstance(other, UserList):

            self.data += other.data

        elif isinstance(other, type(self.data)):

            self.data += other

        else:

            self.data += list(other)

        return self

    def __mul__(self, n):

        return self.__class__(self.data*n)

    __rmul__ = __mul__

    def __imul__(self, n):

        self.data *= n

        return self

    def append(self, item): self.data.append(item)

    def insert(self, i, item): self.data.insert(i, item)

    def pop(self, i=-1): return self.data.pop(i)

    def remove(self, item): self.data.remove(item)

    def count(self, item): return self.data.count(item)

    def index(self, item, *args): return self.data.index(item, *args)

    def reverse(self): self.data.reverse()

    def sort(self, *args, **kwds): self.data.sort(*args, **kwds)

    def extend(self, other):

        if isinstance(other, UserList):

            self.data.extend(other.data)

        else:

            self.data.extend(other)