from inspect import getcallargs, getargspec, ismethod
from functools import wraps
class KeywordRepeatedTypeError(TypeError): pass
def insert_keyword_first(fun, a, k): # based on recipe: 577922
a = list(a)
for idx, arg in enumerate(getargspec(fun).args, -ismethod(fun)): # or [0] in 2.5
if arg in k:
if idx < len(a):
a.insert(idx, k.pop(arg))
else:
break
return (a, k)
def currying(f):
def collector(*a, **k):
@wraps(f)
def caller(*args, **kwargs):
try:
for key in kwargs:
if key in k:
raise KeywordRepeatedTypeError(
"TypeError: %s() got multiple values "
"for keyword argument '%s'" % (f.func_name, key))
kwargs.update(k)
args, kwargs = insert_keyword_first(f, a + args, kwargs)
getcallargs(f, *args, **kwargs)
except KeywordRepeatedTypeError, e:
raise TypeError(e)
except TypeError:
spec = getargspec(f)
if not spec.keywords:
for key in kwargs:
if key not in spec.args:
raise
if len(spec.args) > len(args) + len(set(spec.args) & set(kwargs)):
return collector(*args, **kwargs)
raise
else:
return f(*args, **kwargs)
return caller
return collector()
if __name__ == "__main__":
import unittest
class Test(unittest.TestCase):
def test_args(self):
@currying
def function(a, b, c, d, e, f, *ar, **kw): return (a, b, c, d, e, f, ar, kw)
print function(2, e=5)(4)(x=100, y=1000)(c=3, a=1)(6, 7, 8, z=10000)
#returns (1, 2, 3, 4, 5, 6, (7, 8), {'y': 1000, 'x': 100, 'z': 10000})
@currying
def args(a, b, c): return (a, b, c)
self.assertEquals(args()()(a=1)()(2, 3), (1, 2, 3))
with self.assertRaises(TypeError): args(d=4)
f = args(1)
for x in range(1, 6):
ff = f(x)
for y in range(10, 101, 30):
print ff(y)
@currying
def default_args(a=10, b=20, c=30): return (a, b, c) #cannot curry but works
self.assertEquals(default_args(1, c=3), (1, 20, 3))
@currying
def varargs_keywords(*a, **k):
'''function like that canonot be curried
because it always eats up all arguments on the first call, but will work anyway...'''
return a, k
@currying
def args_varargs(a, b, c, *ar): return a, b, c, ar
self.assertEquals(args_varargs(1, c=3)(2, 4), (1, 2, 3, (4,)))
with self.assertRaises(TypeError): args_varargs(d=4)
@currying
def args_keywords(a, b, c, **k): return a, b, c, k
self.assertEquals(args_keywords(d=4)(1, 3)(b=2), (1, 2, 3, {'d':4}))
with self.assertRaises(TypeError): args_keywords(c=3)(4, b=2, a=1)
@currying
def args_varargs_keywords(a, b, c, *ar, **k): return a, b, c, ar, k
self.assertEquals(args_varargs_keywords(1, 2)(3, d=4), (1, 2, 3, (), {'d':4}))
self.assertEquals(args_varargs_keywords(d=6)(2,a=1)(4,5, c=3), (1,2,3,(4,5),{'d':6}))
with self.assertRaises(TypeError): args_varargs_keywords(a=1)(a=2)(3, 4)
class ObjectMethod(object):
@currying
def metdhod(self, a, b): return a, b
self.assertEquals(ObjectMethod().metdhod(2)(a=1), (1,2))
self.assertEquals(ObjectMethod().metdhod(a=1)(2), (1,2))
unittest.main()
Diff to Previous Revision
--- revision 1 2011-10-28 10:52:23
+++ revision 2 2011-10-28 22:05:55
@@ -3,7 +3,7 @@
class KeywordRepeatedTypeError(TypeError): pass
-def insert_keyword_first(fun, a, k): # based on recepy: 577922
+def insert_keyword_first(fun, a, k): # based on recipe: 577922
a = list(a)
for idx, arg in enumerate(getargspec(fun).args, -ismethod(fun)): # or [0] in 2.5
if arg in k:
