#!/bin/env python

#Copyright ReportLab Europe Ltd. 2000-2012

#see license.txt for license details

#history http://www.reportlab.co.uk/cgi-bin/viewcvs.cgi/public/reportlab/trunk/reportlab/lib/set_ops.py

__version__=''' $Id$ '''

__doc__="""From before Python had a Set class..."""

import types

def __set_coerce(t, S):

    if t is list:

        return list(S)

    elif t is tuple:

        return tuple(S)

    elif t is bytes:

    return S

def unique(seq):

    result = []

    for i in seq:

        if i not in result:

            result.append(i)

    return __set_coerce(type(seq), result)

def intersect(seq1, seq2):

    result = []

    if type(seq1) != type(seq2) and type(seq2) == bytes: seq2 = list(seq2)

    for i in seq1:

        if i in seq2 and i not in result: result.append(i)

    return __set_coerce(type(seq1), result)

def union(seq1, seq2):

    if type(seq1) == type(seq2):

        return unique(seq1 + seq2)

    if type(seq1) == list or type(seq2) == list:

        return unique(list(seq1) + list(seq2))

    if type(seq1) == tuple or type(seq2) == tuple:

        return unique(tuple(seq1) + tuple(seq2))

    return unique(list(seq1) + list(seq2))