www.digitalmars.com         C & C++   DMDScript  

digitalmars.D.learn - Template mixin problem

reply Olli Aalto <oaalto gmail.com> writes:
I already posed this question on the #D channel, but here's for the rest 
of you.

http://tango.pastebin.com/m59b8715f

Here's the error:

oaalto-desktop Projects/workspace/MixinTest> dsss build
mixins/main.d => mixin_test
mixins/HelloWorld.d(7): mixin is not defined
mixins/HelloWorld.d(8): mixin 
mixins.HelloWorld.HelloWorld.HelloSpeaker!() error instantiating
mixins/HelloWorld.d(7): mixin is not defined
mixins/HelloWorld.d(8): mixin 
mixins.HelloWorld.HelloWorld.HelloSpeaker!() error instantiating
Command /home/oaalto/D/dsss/bin/rebuild returned with code 256, aborting.
Error: Command failed, aborting.

Any ideas what's going wrong?

DMD 1.033
DSSS 0.78

O.
Dec 15 2008
parent reply Olli Aalto <oaalto gmail.com> writes:
Ok, downs figured it out on #D. You can't have mixins in templates, 
which is a big disappointment.

Removing the HelloData mixin from HelloSpeaker and all references to 
helloStr it "works".

O.
Dec 15 2008
next sibling parent reply "Bill Baxter" <wbaxter gmail.com> writes:
On Mon, Dec 15, 2008 at 5:48 PM, Olli Aalto <oaalto gmail.com> wrote:
 Ok, downs figured it out on #D. You can't have mixins in templates, which is
 a big disappointment.

 Removing the HelloData mixin from HelloSpeaker and all references to
 helloStr it "works".

Hmm, didn't know that. But also if you import a module that uses a mixin, the module that uses the mixin also needs to import the mixin module. I'm sure that didn't make any sense. I.e. you may need to import mixins.HelloData in mixins.HelloWorld. And maybe import all the mixin modules in in main. --bb
Dec 15 2008
parent reply Olli Aalto <oaalto gmail.com> writes:
Bill Baxter wrote:
 On Mon, Dec 15, 2008 at 5:48 PM, Olli Aalto <oaalto gmail.com> wrote:
 Ok, downs figured it out on #D. You can't have mixins in templates, which is
 a big disappointment.

 Removing the HelloData mixin from HelloSpeaker and all references to
 helloStr it "works".

Hmm, didn't know that. But also if you import a module that uses a mixin, the module that uses the mixin also needs to import the mixin module. I'm sure that didn't make any sense. I.e. you may need to import mixins.HelloData in mixins.HelloWorld. And maybe import all the mixin modules in in main.

Yeah, just tried that and it worked. :) I think all this makes some kind of sense, but having to import the module for HelloData in HelloWorld shouldn't be needed. It's already been mixed-in in HelloSpeaker so from the HelloWorld's standpoint there is no HelloData. But any way glad to have it working. O.
Dec 15 2008
parent Olli Aalto <oaalto gmail.com> writes:
Bill Baxter wrote:
 On Mon, Dec 15, 2008 at 5:58 PM, Olli Aalto <oaalto gmail.com> wrote:
 Bill Baxter wrote:
 On Mon, Dec 15, 2008 at 5:48 PM, Olli Aalto <oaalto gmail.com> wrote:
 Ok, downs figured it out on #D. You can't have mixins in templates, which
 is
 a big disappointment.

 Removing the HelloData mixin from HelloSpeaker and all references to
 helloStr it "works".

mixin, the module that uses the mixin also needs to import the mixin module. I'm sure that didn't make any sense. I.e. you may need to import mixins.HelloData in mixins.HelloWorld. And maybe import all the mixin modules in in main.

sense, but having to import the module for HelloData in HelloWorld shouldn't be needed. It's already been mixed-in in HelloSpeaker so from the HelloWorld's standpoint there is no HelloData. But any way glad to have it working.

But modules are inherited privately by default. If you use "public import blahblah" for the modules the mixins require then you can get around the problem. Also there is a trick that I think h3r3tic first noticed -- you can actually put an import statement inside the template, and at least if it gets mixed into a class, it will work. May work in other cases too, but not so sure about that.

Yes, I know that they are private by default and that's great. My point here is this: (copy pasted from #D) < Odeamus> the way I see this is that when the HelloWorld sees the mixin for HelloSpeaker the HelloSpeaker template should already contain the line "private char[] helloStr" and not the mixin But any way I wrote couple words about what I was after here: http://odefu.blogspot.com/2008/12/composite-oriented-programming.html O.
Dec 15 2008
prev sibling parent "Bill Baxter" <wbaxter gmail.com> writes:
On Mon, Dec 15, 2008 at 5:58 PM, Olli Aalto <oaalto gmail.com> wrote:
 Bill Baxter wrote:
 On Mon, Dec 15, 2008 at 5:48 PM, Olli Aalto <oaalto gmail.com> wrote:
 Ok, downs figured it out on #D. You can't have mixins in templates, which
 is
 a big disappointment.

 Removing the HelloData mixin from HelloSpeaker and all references to
 helloStr it "works".

Hmm, didn't know that. But also if you import a module that uses a mixin, the module that uses the mixin also needs to import the mixin module. I'm sure that didn't make any sense. I.e. you may need to import mixins.HelloData in mixins.HelloWorld. And maybe import all the mixin modules in in main.

Yeah, just tried that and it worked. :) I think all this makes some kind of sense, but having to import the module for HelloData in HelloWorld shouldn't be needed. It's already been mixed-in in HelloSpeaker so from the HelloWorld's standpoint there is no HelloData. But any way glad to have it working.

But modules are inherited privately by default. If you use "public import blahblah" for the modules the mixins require then you can get around the problem. Also there is a trick that I think h3r3tic first noticed -- you can actually put an import statement inside the template, and at least if it gets mixed into a class, it will work. May work in other cases too, but not so sure about that. --bb
Dec 15 2008