Module docstrings don't work with together with Hy core imports

[Kodiologist]

Similarly to #1367, any automatic imports from core will prevent a string literal from being the first statement in a module, and hence from being the module docstring.

$ echo '"hello world" (print (get [1 2] 0))' > test.hy
$ hy -c '(import test) (print test.__doc__)'
1
hello world
$ echo '"hello world" (print (first [1 2]))' > test.hy 
$ hy -c '(import test) (print test.__doc__)'          
1
None

[gilch]

We can just set the __doc__ global and put module docstrings wherever we please. But I'd rather get rid of autoimports altogether somehow. It's causing a lot of problems and the above is just one of them. Hy's core is not discoverable with dir. We can't easily import * from a Hy module, since the Hy core we happen to use in that module comes with it.

What we really want is our own builtins module for Hy. But Python doesn't have an easy way to add that. And dumping our "builtin" stuff into Python's builtins is not nice to the Python side. So we autoimport. #1407 had some ideas on how to deal with that differently.

[vodik]

What we really want is our own builtins module for Hy. But Python doesn't have an easy way to add that.

It does... we just have to drop Python 2 😉 See BuiltinImporter (and get #1518 in...)

[gilch]

Wait, what? Does this really do what we need? Python 2.7 also has a "BuiltinImporter" class, I checked. But it's not clear to me how to use it or what it's good for from those linked docs.