我正在尝试在Python 2.6中实现一个闭包,我需要访问一个非局部变量,但似乎这个关键字在python 2.x中不可用.如何在这些版本的python中访问闭包中的非局部变量？
如果将列表中每个元素的(隐式)索引视为其键,则zipWith有点像关系内连接.它只处理两个输入都具有值的键:
zipWith (+) [1..5] [10..20] == zipWith (+) [1..11] [10..14] == [11,13,15,17,19]
是否存在与外连接对应的规范对应函数？就像是:
outerZipWith :: (a -> b -> c) -> a -> b -> [a] -> [b] -> [c]
outerZipWith _ _ _ [] [] = []
outerZipWith f a' b' [] (b:bs) = f a' b : outerZipWith f a' b' [] bs
outerZipWith f a' b' (a:as) [] = f a b' : outerZipWith f a' b' as []
outerZipWith f a' b' (a:as) (b:bs) …