Someone please tell me how, for I am a newbie and don't know any solutions even to this very simple problem. As I learned dlang using the Dlang tour page, I stuck at the alias & Strings page. I have tried to compile the following simple code many times but still get the same error both from dmd and gdc. They both say that
<----------------------------------------------------
string.d:9:9: error: module string is used as a type
  string str = "This is a test.";
---------------------------------------------------->
whenever I tried compiling this code below
<------------------------------------------
import std.stdio;
import std.string;

void main()
{
    //alias string = immutable(char)[];
    string str = "This is a test.";
}
------------------------------------------->
However, when I uncomment the alias~ line above,
both dmd and gdc can compile the code. I thought
that the string object is already defined in the
package or somewhere beforehand, but am I wrong?

On Monday, 5 March 2018 at 23:34:50 UTC, askjfbd wrote:
> string.d

The problem is you named the file string.d and didn't give a `module xxxxx;` statement in the code, so the compiler assumed the module is named after the file.... and thus introduced a local name `string` referring to the module, overriding the built in one.

You can still refer to the built in one by saying `.string foo = "bar";` - yes, the leading dot, which tells it to use the global instead of local name.

Or by putting `module mytest.string;` at the top, so the module has a two-part name (I recommend this in all cases anyway btw, it is the best way to avoid conflicts as you import more modules).

Or just renaming the file from string.d to almost_anything_else.d, which will also avoid the local name override.

On Monday, 5 March 2018 at 23:34:50 UTC, askjfbd wrote:
> Someone please tell me how, for I am a newbie and don't know any solutions even to this very simple problem. As I learned dlang using the Dlang tour page, I stuck at the alias & Strings page. I have tried to compile the following simple code many times but still get the same error both from dmd and gdc. They both say that...

This is mistake I made too, when i began using D.

I quickly got into the habit of putting

module test;

at the beginning of every file I create, unless I determine a better module name.

Actually, I wrote my own IDE, so it does that for me whenever I select a new D file.

Personally, I think that is one of the first things newcomers need to learn about - modules.

-------------
"Modules have a one-to-one correspondence with source files. The module name is, by default, the file name with the path and extension stripped off, and can be set explicitly with the module declaration."

"Modules automatically provide a namespace scope for their contents."

https://dlang.org/spec/module.html

------------

On Monday, 5 March 2018 at 23:42:59 UTC, Adam D. Ruppe wrote:
> On Monday, 5 March 2018 at 23:34:50 UTC, askjfbd wrote:
>> string.d
>
> The problem is you named the file string.d and didn't give a `module xxxxx;` statement in the code, so the compiler assumed the module is named after the file.... and thus introduced a local name `string` referring to the module, overriding the built in one.
>
> You can still refer to the built in one by saying `.string foo = "bar";` - yes, the leading dot, which tells it to use the global instead of local name.
>
> Or by putting `module mytest.string;` at the top, so the module has a two-part name (I recommend this in all cases anyway btw, it is the best way to avoid conflicts as you import more modules).
>
> Or just renaming the file from string.d to almost_anything_else.d, which will also avoid the local name override.

Thanks for the precise advice. How foolish I was and how quickly you gave me the answer! I'll have to learn a lot more about D and more about modules. Since C and common lisp, which I have learned so far, have almost nothing to do with name conflicts, I couldn't imagine that I was still wrong. :) Thank you.

On Tuesday, 6 March 2018 at 00:18:14 UTC, psychoticRabbit wrote:
> On Monday, 5 March 2018 at 23:34:50 UTC, askjfbd wrote:
>> Someone please tell me how, for I am a newbie and don't know any solutions even to this very simple problem. As I learned dlang using the Dlang tour page, I stuck at the alias & Strings page. I have tried to compile the following simple code many times but still get the same error both from dmd and gdc. They both say that...
>
> This is mistake I made too, when i began using D.
>
> I quickly got into the habit of putting
>
> module test;
>
> at the beginning of every file I create, unless I determine a better module name.
>
> Actually, I wrote my own IDE, so it does that for me whenever I select a new D file.
>
> Personally, I think that is one of the first things newcomers need to learn about - modules.
>
> -------------
> "Modules have a one-to-one correspondence with source files. The module name is, by default, the file name with the path and extension stripped off, and can be set explicitly with the module declaration."
>
> "Modules automatically provide a namespace scope for their contents."
>
> https://dlang.org/spec/module.html
>
> ------------

Thank you. I will learn about modules from now on. I thought I was right until you two replied to me. ;) Can you make your own IDE? That's great! If it were OpenSource, I would gladly download it for myself to avoid this sort of annoying experience. Thanks.