sass/compass: nested include of all-foo-sprites mixin - extjs

Question

I have generate automatic sprite classes with
#import "icons/*.png";
#include all-icons-sprites;
The import and include will magically generate classes like:
.icons-application_go {
background-position: 0 -16px;
}
(which corresponds to icons/application_go.png file)
However, I need to include my sprites so that the resulting classes looks like this
.x-btn-icon.icons-application_go {
background-position: 0 -16px;
}
.x-btn-icon.icons-delete {
background-position: 0 0;
}
I've tried to do
.x-btn-icon {
#include all-icons-sprites;
}
but it will result in
.x-btn-icon .icons-application_go {
background-position: 0 -16px;
}
.x-btn-icon .icons-delete {
background-position: 0 0;
}
,so selecting childs of .x-btn-icon but not elements with class="x-btn-icon icons-delete"
Right now, I have
.x-btn-icon.icons-add { #include icons-sprite(add); }
in my SASS. But I would need to do this manually for every item. I have exactly 1000 icons in this set, so this would be tedious :-)
Is there a way to loop through all icons name (like "add") and output
.x-btn-icon.icons-$foo { #include icons-sprite($foo); }
?
As per suggestion from #cram1010, I've also tried
#import "icons/*.png";
$icons-sprite-base-class: "&.icons-";
.x-btn-icon {
#include all-icons-sprites;
}
But I got the following error:
Invalid CSS after "": expected selector, was "&.icons-"
(in /Users/pasc/projects/bss-io-demo/vendor/gems/bss-io-app/app/assets/stylesheets/bss.io.app.css.scss)

Answer 1

Following works. The key is referencing parents selectors.
Sass:
#mixin all-icons-sprites {
&.icons-application_go {
background-position: 0 -16px;
}
&.icons-delete {
background-position: 0 0;
}
}
.x-btn-icon {
#include all-icons-sprites;
}
Is compiled to following CSS:
.x-btn-icon.icons-application_go {
background-position: 0 -16px;
}
.x-btn-icon.icons-delete {
background-position: 0 0;
}
UPDATE 1
It seems I misunderstood the question, as your mixin is automatically generated.
Have you tried of changing the $<map>-sprite-base-class option for sprites in compass, so it includes the referencing parent selectors &?
$icons-sprite-base-class: "&.icons-";
UPDATE 2
For the comments, it seems that it's not possible because of compass source code. So surely a new bug should be reported to the Compass team: github.com/chriseppstein/compass/issues