Import concerns revisited

[Walter Bright]

Ivan Senji wrote:
> There should be a big difference (if I understand things correctly):
> A simple example:
> 
> If I have:
> 
> module m1;
> 
> int func(){return 1;}
> 
> and
> 
> module mainmodule;
> 
> import m1;
> 
> void main()
> {
>   writefln(func());
>   writefln(m1.func());
> }
> 
> there are no problems with that!
> 
> But if I add:
> 
> module m2;
> 
> int func(){return 2;}
> 
> and change mainmodule to:
> 
> import m1;
> import m2;
> 
> void main()
> {
>   writefln(func());     //<- conflict
>   writefln(m1.func());
>   writefln(m2.func());
> }
> 
> And suddenly I get a lot of conflicts.

I agree, but the "static import" resolves that.


> Sure there is a way to solve it by adding:
> 
> alias m1.func func;
> 
> And then use m2.func to use func from m2.
> 
> But what if I wanted to give m2.func a totally different name to avoid
> confusion, i can try to add this:
> 
> alias m2.func someOtherName; instead of alias m1.func func;
> 
> But then once again I would get an error about a conflict:
> 
> Once again there is a solution:
> 
> alias m1.func func;
> alias m2.func f2;
> 
> And it works OK, but the intention here is a bit hidden.
> 
> Conclusion:
> 
> import m2.func as f2;
> 
> is not the same as:
> 
> import m2;
> alias m2.func f2;
> 
> but is equivalent to:
> 
> import m2;
> alias m2.func f2;
> //insert here a possibly huge number of aliases to avoid conflicts of
> m2.func with func from other imported modules.

If "static import" is used, there aren't any conflicts.

There are two issues here:

1) the "second class name lookup" characteristic of import.
2) inserting a name from one scope into another (possibly renaming it in 
the process)

static import does (1) by importing but disabling the second class lookup.
alias does (2).