Created
August 16, 2010 14:12
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#!/usr/bin/env python | |
# -*- encoding: utf-8 -*- | |
class Enumerable(object): | |
def __init__(self, source, inext): | |
self.source = source | |
self.inext = inext | |
def __iter__(self): | |
return self | |
def next(self): | |
return self.inext(self.source) | |
def select(self, selector): | |
def inext(source): | |
return selector(source.next()) | |
return Enumerable(self, inext) | |
def where(self, pred=bool): | |
def inext(source): | |
while True: | |
item = source.next() | |
if pred(item): | |
return item | |
return Enumerable(self, inext) | |
def take(self, count): | |
class inner(object): | |
def __init__(self): | |
self.index = 0 | |
def inext(self, source): | |
while True: | |
item = source.next() | |
if self.index < count: | |
self.index += 1 | |
return item | |
else: | |
raise StopIteration | |
return Enumerable(self, inner().inext) | |
def make(source, *methods): | |
def iter(s): | |
for v in s: | |
yield v | |
def inext(s): | |
return s.next() | |
e = Enumerable(iter(source), inext) | |
for method in methods: | |
e = method(e) | |
return e | |
def select(selector): | |
def inner(source): | |
return source.select(selector) | |
return inner | |
def where(pred=bool): | |
def inner(source): | |
return source.where(pred) | |
return inner | |
def take(count): | |
def inner(source): | |
return source.take(count) | |
return inner | |
def main(): | |
import linq | |
def put(q): | |
for n in q: | |
print n, | |
a = [{'key': i, 'value': i * 2} for i in range(100)] | |
# メソッドチェイン | |
q = linq.make(a).take(20).where(lambda x: x['key'] % 2).select(lambda x: x['value']) | |
put(q) | |
# メソッドチェイン風 | |
q = linq.make(a | |
, linq.take(20) | |
, linq.where(lambda x: x['key'] % 2) | |
, linq.select(lambda x: x['value']) | |
) | |
put(q) | |
if __name__ == '__main__': | |
main() |
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fixed: http://gist.github.com/527054