1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
|
'Non-standard higher-order functions'
def partial(f, *a, **k): # (2.5 provides this)
# Don't mutate 'a' or 'k' since each call to 'g' shares them
def g(*b, **l):
m = k.copy()
m.update(l)
return f(*(a + b), **m)
return g
def compose(*fs):
''' ``compose(f,g,...,h)(*args, **kw) == f(g(...(h(*args, **kw))))``
>>> compose(len, str)(100)
3
>>> compose(len, str, len, str)(1234567890)
2
>>> compose()(1)
1
>>> map(compose(sum, range, len), ['foo', 'asdf', 'wibble'])
[3, 6, 15]
'''
if len(fs) == 0:
return lambda x: x
binary_compose = lambda f,g: lambda *args, **kw: f(g(*args, **kw))
return reduce(binary_compose, fs)
|
