I have a bit of code which is the definition of a class Preferences, which has:

	this() {
		filePath = expandTilde(chainPath("~", ".config", "me-tv", "preferences.yml").array);

filePath is a member of the class. Now if I have a module level instance (clearly not a good move but OK for now):

   public auto preferences = new Preferences;

then Dub using DMD on Debian Sid gives me:

/usr/include/dmd/phobos/std/path.d(3970,31): Error: getenv cannot be interpreted at compile time, because it has no available source code
/usr/include/dmd/phobos/std/path.d(4064,41):        called from here: expandFromEnvironment(inputPath)
source/preferences.d(36,25):        called from here: expandTilde(array(chainPath("~", ".config", "me-tv", "preferences.yml")))

What is the official way of getting preferences initialised at run time and not compile time.

-- 
Russel.
===========================================
Dr Russel Winder      t: +44 20 7585 2200
41 Buckmaster Road    m: +44 7770 465 077
London SW11 1EN, UK   w: www.russel.org.uk

On 26/05/2018 3:58 AM, Russel Winder wrote:
> I have a bit of code which is the definition of a class Preferences,
> which has:
> 
> 	this() {
> 		filePath = expandTilde(chainPath("~", ".config", "me-tv", "preferences.yml").array);
> 
> filePath is a member of the class. Now if I have a module level
> instance (clearly not a good move but OK for now):
> 
>     public auto preferences = new Preferences;
> 
> then Dub using DMD on Debian Sid gives me:
> 
> /usr/include/dmd/phobos/std/path.d(3970,31): Error: getenv cannot be interpreted at compile time, because it has no available source code
> /usr/include/dmd/phobos/std/path.d(4064,41):        called from here: expandFromEnvironment(inputPath)
> source/preferences.d(36,25):        called from here: expandTilde(array(chainPath("~", ".config", "me-tv", "preferences.yml")))
> 
> What is the official way of getting preferences initialised at run time
> and not compile time.

Use a module constructor to initialize your global.

On Sat, 2018-05-26 at 04:00 +1200, rikki cattermole via Digitalmars-d- learn wrote:
> […]
> 
> Use a module constructor to initialize your global.

Splendid idea! :-)

I know, I should have thought of that.

I note that if you click "Constructor" on https://dlang.org/spec/module
.html
you get taken to https://dlang.org/spec/class.html#Constructor which
really does help describe the concept of a module constructor.

-- 
Russel.
===========================================
Dr Russel Winder      t: +44 20 7585 2200
41 Buckmaster Road    m: +44 7770 465 077
London SW11 1EN, UK   w: www.russel.org.uk