On Mon, Sep 11, 2017 at 04:06:14PM +0000, אלעזר wrote: > I like it. For previous discussion of this idea see here: > https://mail.python.org/pipermail/python-ideas/2016-September/042527.html > > I don't see this mentioned in the PEP, but it will also allow (easy) > description of contracts and dependent types.
How? You may be using a different meaning to the word "contract" than I'm familiar with. I'm thinking about Design By Contract, where the contracts are typically much more powerful than mere type checks, e.g. a contract might state that the argument is float between 0 and 1, or that the return result is datetime object in the future. There are (at least?) three types of contracts: preconditions, which specify the arguments, postconditions, which specify the return result, and invariants, which specify what doesn't change. I don't see how you can specify contracts in a single type annotation. -- Steve _______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/
