Macro a2lmacros::a2ml_specification

a2ml_specification!() { /* proc-macro */ }

The a2ml_specification! macro enables application to conveniently decode and use IF_DATA defined though A2ML. The macro uses an “enhanced A2ML” language to define the items. Rust data structures and associated code will be generated for items defined inside of the macro.

For example a file might have the following definition inside its A2ML block:

block "IF_DATA" taggedunion {
    "SOME_DATA" struct {
        uint;
        uint;
    }
}

The a2ml_specification! can process this form directly, but the struct and its members have no names. The “enhanced A2ML” form of this would be:

block "IF_DATA" taggedunion {
    "SOME_DATA" struct SomeData {
        uint month;
        uint day;
    }
}

Finally, the A2ml inside the macro must be preceded by a header that names the content; all together it looks like this:

a2ml_specification! {
    <MyA2mlSpec>
    block "IF_DATA" taggedunion {
        "SOME_DATA" struct SomeData {
            uint month; /// a doc comment for month that will be preserved
            uint day; /// a doc comment for day
        }
    }
}

The macro will also generate a text constant containing standard (basic) A2ML matching the enhanced definition in the macro; it is called uppercase(macroname)_text. For the example it is MYA2MLSPEC_TEXT.

Now you can load IfData from an a2l file:

let a2l_file: A2lFile = a2lfile::load(the_filename, Some(MYA2MLSPEC_TEXT.to_string()), &mut logger, false);
let my_data = MyA2mlSpec::load_from_ifdata(&a2l_file.project.modules[0].if_data[0]);