API Evolution

[bearophile]

This is a bit related to the discussion about version().

In the Lambda the Ultimate blog-forum they are discussing about better support in languages for API Evolution:

http://lambda-the-ultimate.org/node/2950

In the discussion someone has said that it may be useful a syntax to specify what version of a module/package must be imported. (And now and then I have seen people in Python mailing lists ask for something similar, they have several versions of the same module/package and they want other modules to import only the right version).

A first possible raw idea:

This looks for a module foo strictly version 1.3:
import foo(1.3, 1.4) : bar;

This looks for a module foo version 1.3 or 1.4 only:
import foo(1.3, 1.4) : bar;

This looks for a module foo version 1.3 or successive:
import foo(1.3, +) : bar;

The compiler is of course supposed to look for modules by itself, as bud does, and it rises a compilation error if an acceptable version isn't available.

That idea may also need a way to define the version of the current module, a raw idea:

module foo(1.4);

A small problem is that versions of such module/package will have the same name, so you can't put them in the same directory...

Bye,
bearophile