Using agent with external (or class) methods

[Louis M]

Hello everyone.

I try to use an external method in the {C_EXTERNAL} class like this:

    frozen method_name(a_object:POINTER):POINTER
        external
            "C++ inline use <Box2D.h>"
        alias
            "((CType *)$a_object)->functionName()"
        end

in an agent call. I define the {FUNCTION} variable like this:

    l_method:FUNCTION[POINTER, POINTER]

Finally, I assign the agent like this:

    l_method := agent {C_EXTERNAL}.method_name

When I compile that, I have a VUAR error saying that the type of the
agent is:

    FUNCTION [C_EXTERNAL, POINTER, POINTER]

instead of :

    FUNCTION [POINTER, POINTER]

Since it is a class method, I don't have an object of type {C_EXTERNAL}
to use in the agent call. I have a workaround using:

    l_method := agent (a_item:POINTER):POINTER do Result :=
{C_EXTERNAL}.method_name(a_item) end

But I think that this is ugly (particularly when used as method
argument). So is there a way to use a more concise technique of creating
an agent from external or class method?

Thanks a lot,

Louis M

[Alexander Kogtenkov]

Agents were introduced in the language long time before class features. Class features are a recent addition. So, I believe, there is no special syntax for class-based (as opposed to object-based) agents at the moment.

 

Regards,

Alexander Kogtenkov

 

 

'Louis M' via Eiffel Users <eiffel...@googlegroups.com>:
 

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[Louis M]

Ok. Thanks.

Louis M

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