Consider:

with (import std.stdio)
int fun(int x/*, File f*/)
{
    // f.writeln("In: ", x);
    return x * x;
}

Such situations occur during refactorings and code evolution. The import is no longer used. Should the compiler flag that as an error, or leave it be?


Andrei

On Saturday, 24 December 2016 at 20:32:58 UTC, Andrei Alexandrescu wrote:
> Consider:
>
> with (import std.stdio)
> int fun(int x/*, File f*/)
> {
>     // f.writeln("In: ", x);
>     return x * x;
> }
>
> Such situations occur during refactorings and code evolution. The import is no longer used. Should the compiler flag that as an error, or leave it be?
>
>
> Andrei

I'd use a warning, as with unused variables: the code is in an OK state when in the middle of a work (such as temporarily commenting a block), but less OK for a release.
Also, Visual Studio highlights unused includes for C#, which is nice.

On 25/12/2016 9:32 AM, Andrei Alexandrescu wrote:
> Consider:
>
> with (import std.stdio)
> int fun(int x/*, File f*/)
> {
>     // f.writeln("In: ", x);
>     return x * x;
> }
>
> Such situations occur during refactorings and code evolution. The import
> is no longer used. Should the compiler flag that as an error, or leave
> it be?
>
>
> Andrei

How costly is the checking of if said import is used?

On Saturday, December 24, 2016 15:32:58 Andrei Alexandrescu via Digitalmars- d wrote:
> Consider:
>
> with (import std.stdio)
> int fun(int x/*, File f*/)
> {
>      // f.writeln("In: ", x);
>      return x * x;
> }
>
> Such situations occur during refactorings and code evolution. The import is no longer used. Should the compiler flag that as an error, or leave it be?

I say leave it be. It's the sort of thing that risks causing problems with conditional compilation (not as bad as in some cases, but I still don't think that it's worth the risk). IMHO, this is the sort of thing that should be left up to a lint tool, and there's technically nothing wrong with it.

- Jonathan M Davis

On Saturday, 24 December 2016 at 20:32:58 UTC, Andrei Alexandrescu wrote:
> Such situations occur during refactorings and code evolution. The import is no longer used. Should the compiler flag that as an error, or leave it be?

please, no. "this is a work for a linter", as Walter likes to say (sorry for inexact quoting ;-).

On Saturday, 24 December 2016 at 20:32:58 UTC, Andrei Alexandrescu wrote:
> Consider:
>
> with (import std.stdio)
> int fun(int x/*, File f*/)
> {
>     // f.writeln("In: ", x);
>     return x * x;
> }
>
> Such situations occur during refactorings and code evolution. The import is no longer used. Should the compiler flag that as an error, or leave it be?
>
>
> Andrei

Generic code and generated code would suffer from an error being generated there.

Andrei Alexandrescu via Digitalmars-d <digitalmars-d@puremagic.com> napsal So, pro 24, 2016 v 9∶32 :
> Consider:
> 
> with (import std.stdio)
> int fun(int x/*, File f*/)
> {
>     // f.writeln("In: ", x);
>     return x * x;
> }
> 
> Such situations occur during refactorings and code evolution. The import is no longer used. Should the compiler flag that as an error, or leave it be?
> 
> 
> Andrei

for such things there should be support in IDE or use some lint tool