root/hodgestar/PythonCode/SmallScripts/curry.py

"""An attempt at implementing currying in Python."""

import inspect

class Curry(object):
    def __init__(self, func, arg_names=None, arg_values=None):
        self.func = func

        if arg_names is None:
            args, varargs, varkw, defaults = inspect.getargspec(self.func)
            self.arg_names = args
        else:
            self.arg_names = arg_names

        if arg_values is None:
            self.arg_values = ()
        else:
            self.arg_values = arg_values

    def __call__(self, *params):
        new_params = self.arg_values + params
        if len(new_params) >= len(self.arg_names):
            return self.func(*new_params)
        else:
            return Curry(self.func, arg_names=self.arg_names,
                         arg_values=new_params)

if __name__ == "__main__":
    print "Running some basic tests ..."

    def f(x,y):
        return x + y
    cf = Curry(f)

    cf_5 = cf(5)
    cf_10 = cf(10)

    assert cf(5)(6) == 11
    assert cf_5(7) == 12
    assert cf_10(12) == 22

    def g(x,y,z,w):
        return (x - y) + (z - w)
    cg = Curry(g)

    cg_2_1 = cg(2)(1)
    cg_3_4_5 = cg(3)(4)(5)
    cg_12 = cg(12)

    assert cg(4)(3)(2)(1) == 2
    assert cg_2_1(7)(5) == 3
    assert cg_3_4_5(12) == -8
    assert cg_12(2)(8)(4) == 14