On Sun, Sep 30, 2018 at 11:54 AM Steven D'Aprano steve@pearwood.info wrote:
This discussion is for those of us who would like to include DbC in our projects but don't like existing solutions. C++ being designed with a shovel is not relevant.
(Except in the sense that we should always be careful about piling on feature upon feature into Python.)
And as such, I do not want to see dedicated syntax for no purpose other than contracts. What I'm interested in is (a) whether something can and should be added to the stdlib, and (b) whether some specific (and probably small) aspect of it could benefit from language support. As a parallel example, consider type hints. The language has ZERO support for special syntax for a language of types. What you have is simple, straight-forward names like "List", and the normal behaviours that we already can do such as subscripting. There is language support, however, for attaching expressions to functions and their arguments.
At the moment, I'm seeing decorator-based contracts as a clunky version of unit tests. We already have "inline unit testing" - it's called doctest - and I haven't seen anything pinned down as "hey, this is what it'd take to make contracts more viable". Certainly nothing that couldn't be done as a third-party package. But I'm still open to being swayed on that point.
ChrisA