Inconsistencies between global imports and function local imports

[Jonathan M Davis]

On Wednesday 13 July 2011 11:56:10 Tyro[a.c.edwards] wrote:
> Methinks function local imports (introduced in 2.054) is a great idea,
> however if it is to be allowed, I believe it should provide all the
> functionality of global imports: which it currently does not.
> 
> import std.stdio;
> import std.string;
> import std.conv;
> 
> // Note: all of these import formats work if imported here but only
> // the first work if imported locally to the function.
> 
> //import std.utf;
> //import std.utf: toUTF16z;
> //import std.utf: wcp = toUTF16z;
> 
> void main()
> {
> 	auto s = "漢字を書くのはどうかな～？";
> 	auto s1 = genText(s);
> 	writeln(to!string(typeid(s1)));
> }
> 
> auto genText(string t)
> {
> 	import std.utf;	// This works
> 	//import std.utf: toUTF16z; // This doesn't
> 	//import std.utf: wcp = toUTF16z; // Neither does this
> 
> 	version(Unicode)
> 	{
> 		// Note: Everything here works with global import
> 		// but only the first line works with function local imports
> 
> 		return toUTF16z(t);   // This works
> 		//return t.toUTF16z;  // This doesn't
> 		//return wcp(t);      // Neither does this
> 		//return t.wcp;       // Or this
> 	}
> 	else
> 	{
> 		return t.toStringz;
> 	}
> }

import std.utf: toUTF16z;

is broken to begin with:

http://d.puremagic.com/issues/show_bug.cgi?id=314
http://d.puremagic.com/issues/show_bug.cgi?id=5161

Rather than just importing the symbol like it should, a selective import 
essentially create a new symbol. So, that's probably why it doesn't work when 
importing inside of a function.

> [OT - toUTFz]
> 
> Wasn't there discussion about adding toUTFz to the std.utf? For some
> reason I thought that was forthcoming in 2.054... whatever happened there?

It hasn't been merged in yet. It should be in 2.055.

https://github.com/D-Programming-Language/phobos/pull/123

- Jonathan M Davis