Meaning of the dot-function syntax

[dhs]

On Sunday, 1 October 2023 at 09:20:32 UTC, Anonymouse wrote:
> On Sunday, 1 October 2023 at 08:22:48 UTC, dhs wrote:
>> Hi,
>>
>> What's the meaning of the dot in the call to writeln() below?
>>
>> ```d
>>     .writeln("Hello there!");
>> ```
>>
>> I haven't found this in the spec or anywhere else. This is 
>> used very often in the source code for Phobos.
>>
>> Thanks,
>> dhs
>
> Quote https://dlang.org/spec/module.html#module_scope_operators;
>
>> A leading dot (`.`) causes the identifier to be looked up in 
>> the module scope.
>> 
>> ```d
>> int x;
>>
>> int foo(int x)
>> {
>>     if (y)
>>         return x;  // returns foo.x, not global x
>>     else
>>         return .x; // returns global x
>> }
>> ```

Oh thank you, especially the link to the spec!