Better handling of callables

[alexandre]

Hello,

Instead to use a function, I prefer to write a class aiming a better description of my analysis rules. So, I defined a callable:

class MyCallable(object):
    def __init__(self):
        # proof.Analysis will look for a dunder name attribute (duck typing)
        self.__name__ = self.__class__.__name__

    def __call__(self, data):
        # analysis rules

Then, I use it in the Analysis.then method:

import proof

analysis_one = MyCallable()
myproof = proof.Analysis(initial_data)

myproof.then(analysis_one)

The proof.Analisys._fingerprint is considering only functions and instead any callable like.

TL;DR I got this exception: https://github.com/python/cpython/blob/master/Lib/inspect.py#L624

I think this PR could be an initial step to a better way to handle callable in this method (_fingerprint).

P.S - I'm sorry if I broke some PR rule/template. I would be happy to discuss this point, improve this PR and write more tests if necessary.

[onyxfish]

Hi @alexandre, this looks great. It's an oversight on my part that callables aren't supported. I definitely intended for this to work. I'll merge this into the next release.

[alexandre]

@onyxfish ,

I'm glad you did like. I could improve this pull request with more some tasks:

• the attribute _func should has a more suggestive name. If implement the method __call__, can be used (if makes quak! == is a duck). So what about rename to _callable ?
• would be great if the docs explain that you need implement an attribute __name__ if you are not using a function
• for last, but no for that less important: an example in the docs about this alternative way.

What do you think? would be better I open an issue ?

[onyxfish]

Those changes sound great! Please feel free to go ahead and implement them on this pull request. No need to file another issue.

[alexandre]

Ok! :]