On 9/22/14, 12:09 AM, Walter Bright wrote:
On 9/21/2014 11:36 PM, Jacob Carlborg wrote:
You better write down the scope rules as well. It gets complicated
with base
classes, template mixins and all features available in D.
Sure, I had thought they were.
BTW, template mixins work exactly like imports. See "Mixin Scope" here:
https://dlang.org/template-mixin
D lookup rules are logical and relatively simple.
In the case of local imports however, there's definitely an element of
surprise, and also an issue akin to hijacking. Consider:
void main(string[] args) {
import some_module;
... use args ...
}
Let's assume module "some_module" does not define a name "args". All
works fine.
Time goes by, some_module gets updated to also define the name "args".
Now this application is recompiled and may actually compile
successfully, but the semantics has changed - it doesn't use the "args"
in the parameter list, but instead the symbol exported by some_module.
That's clearly something difficult to ignore. It's one of those cases in
which logical and relatively simple doesn't fit the bill the same way
that a pair of pants built out of simple shapes like cylinders and
hemispheres won't be a good fit.
We must look into this.
Andrei
