#!/usr/bin/env python
# -*- coding: utf-8 -*-

from pprint import pprint

class IterPack(object):
    def __init__(self, iterable=None):
        self._parent   = None
        self._iterable = None
        self._history  = [iterable]
    
    def end(self, deep=1):
        deep = abs(int(deep))
        if deep <= (len(self._history) - 2):
            res = self._history[deep]
        else:
            res = self._history[1]
        return res
    
    def __iter__(self):
        if not self._iterable:
            self._create_iterator()
        return self._iterable.__iter__()
    
    def __call__(self, param):
        return self._history[-1](param)
    
    def _create_iterator(self):
        res = self._history[0]
        for _lambda in self._history[1:]:
            res = _lambda(res)
        self._iterable = res
        return self
    
    def imap(self, _lambda):
        res = lambda iterable: (_lambda(item) for item in iterable)
        res = IterPack(res)
        self._history.append(res)
        return self
    
    def ifilter(self, _lambda):
        res = lambda iterable: (item for item in iterable if _lambda(item))
        res = IterPack(res)
        self._history.append(res)
        return self
    
    def irange(self, count):
        self._history[-1] = xrange(count)
        return self


def main():
    a = IterPack(xrange(10))
    a.imap(lambda x: x**2).imap(lambda x: x + 11).ifilter(lambda x: x%2!=0)
    a.end(1).imap(lambda x: x*3)
    
    for x in a: print x
    for x in a._history: print x._history if hasattr(x, '_history') else x
    
    print
    b = IterPack()
    b.irange(5)
    
    for x in b: print x

if __name__ == '__main__':
    main()

#!/usr/bin/env python
# -*- coding: utf-8 -*-

from pprint import pprint

class IterPack(object):
    def __init__(self, iterable=None, parent=None):
        self._parent   = parent
        self._iterable = None
        if not self._parent:
            self._history  = [IterPack(iterable, parent=self)]
        else:
            self._history  = [iterable]
        #self._history  = [iterable]
    
    def end(self, deep=1):
        deep = abs(int(deep))
        if deep <= (len(self._history) - 2):
            deep = -1 - deep
            res = self._history[deep] 
        else:
            res = self._history[1]
        return res
    
    def back(self):
        res = self._parent if self._parent else self
        return res
    
    def __iter__(self):
        if not self._iterable:
            self._create_iterator()
        return self._iterable.__iter__()
    
    def __call__(self, param):
        return self._history[-1](param)
    
    def _create_iterator(self):
        res = self._history[0]
        for _lambda in self._history[1:]:
            res = _lambda(res)
        self._iterable = res
        return self
    
    def imap(self, _lambda):
        res = lambda iterable: (_lambda(item) for item in iterable)
        res = IterPack(res, parent=self)
        self._history.append(res)
        return self
    
    def ifilter(self, _lambda):
        res = lambda iterable: (item for item in iterable if _lambda(item))
        res = IterPack(res, parent=self)
        self._history.append(res)
        return self
    
    def irange(self, count):
        self._history[-1] = IterPack(xrange(count))
        return self
    
    def _add(self, iterable):
        self._history[-1] = IterPack(iterable, parent=self)
        return self

    def __str__(self, level=0):
        res = []
        if level==0: res.append('IterPack START\n')
        for item in self._history:
            row = "{PS}{INDENT}+ -> {TYPE} {HASH}\n".format(
                   INDENT = '|    '*level,
                   TYPE   = type(item),
                   HASH   = hex(hash(item)),
                   PS     = '|\n' if not level else ''
                   )
            res.append(row)
            if hasattr(item, '_history'):
                res.extend(item.__str__(level=level+1))
        if level==0: res.append('END')
        return ''.join(res)


def main():
    a = IterPack(xrange(10000))
    a.imap(lambda x: x**2).imap(lambda x: x + 11).ifilter(lambda x: x%2!=0)
    a.ifilter(lambda x: x%3!=0).ifilter(lambda x: x%7!=0)
    a.end().imap(lambda x: x*3).imap(lambda x: x+1).imap(lambda x: x+1).back()
    
    b = IterPack()
    b.irange(5).imap(lambda x: x**3).imap(lambda x: x + 11).ifilter(lambda x: x%2!=0)
    
    print list(a)
    #print list(b)
    print a
    #print b

if __name__ == '__main__':
    main()