paren to factor

factor.py

# ~*~ coding:utf-8 ~*~
"""
数学でよく使う、掛け算記号の省略をやってみた
"""


def _(method):
    def __(self, *args, **kw):
        r = getattr(float, method)(self, *args, **kw)
        return Float2(r) if isinstance(r, float) else r
    return __


def _meta(cls, basetypes, d):
    methods = dir(float)
    methods = (method for method in methods if method not in d)
    for method in methods:
        if method not in ['__new__', '__init__',
                          '__getattr__', '__getattribute__',
                          '__setattr__', '__setattribute__',
                          '__delattr__']:
            d[method] = _(method)
    return type(cls, basetypes, d)


class Float2(float):

    __metaclass__ = _meta

    def __call__(self, x):
        return Float2(self * x)

if __name__ == '__main__':
    x = Float2(1.0)
    y = Float2(1.0)
    print (x + 3)(x - 2)
    print x(x + 1)(x + 2)(x + 3)
    print (x + 1)(y - 2) + (x + 1)(y + 3) == (x + 1)(2 * y + 1)