SimpleClassDiagrams diamond inheritance

[joeriexelmans]

While multiple inheritance is supported in the SimpleClassDiagrams formalism, creating an instance that has diamond inheritance gives an error "500:constraint (post-create noInheritanceLoops) failed".

Is this intended behavior?

• If so, we must make it explicit that diamond inheritance is not allowed.
• Otherwise, the constraint checking function should be fixed to allow this.

The constraint checking function is currently as follows:

var mm      = '/Formalisms/__LanguageSyntax__/SimpleClassDiagram/SimpleClassDiagram/',
    nout    = getNeighbors('>',mm+'Class'),
    visited = [];
function dfs(to_visit)
{
    var curr = to_visit.pop();
    if( curr == undefined )
        return true;
    else if( visited.indexOf(curr) > -1 )
        return false;
    else
    {
        visited.push(curr);
        var ntype = (getAttr('$type',curr) == mm+'Class' ? 
                    mm+'Inheritance' : mm+'Class');
        return dfs( to_visit.concat(getNeighbors('>',ntype,curr)) );
    }
}
dfs(nout);

[BentleyJOakes]

Thanks for the report Joeri.

My concern is that if diamond inheritance was allowed, that AToMPM would be able to correctly handle the inheritance of attributes. Not even the usual problem of resolving conflicts, but also just making sure that all attributes are properly inherited if there is more than one super-class.

Is this a blocker for you? For now, it would be best to create a third class between those two which inherits from AbstractSegment and has the attributes of the others, set manually.

Perhaps in the future we can relax this check and go through the tests to see if anything else needs updating.

[joeriexelmans]

Not a blocker. I asked my students to think of a workaround :)