Packages — Representative Notation

// A named package containing owned members
package VehicleSystem {
    // owned members go here
}

// Elements declared inside a package body
// are owned members of that package (namespace membership)
package VehicleSystem {
    part def Engine;
    part def Chassis;
}

// Public import makes all public members of the
// imported package visible in the importing namespace,
// AND re-exports them to any further importers.
package AutomotiveLibrary {
    part def Engine;
    part def Wheel;
}

package VehicleDesign {
    import AutomotiveLibrary::*;
    // Engine and Wheel are now directly accessible
    // and re-exported from VehicleDesign
}

// Private import makes all public members visible
// in the importing namespace but does NOT re-export them.
package AutomotiveLibrary {
    part def Engine;
}

package VehicleDesign {
    private import AutomotiveLibrary::*;
    // Engine is accessible here but NOT re-exported
}

// A filter import applies a filter condition to restrict
// which members are imported from the target package.
// Only members satisfying the filter expression are visible.
package AutomotiveLibrary {
    part def Engine { attribute mass : Real; }
    part def Wheel  { attribute mass : Real; }
}

package LightweightComponents {
    import AutomotiveLibrary::* filter mass < 50;
    // Only members whose 'mass' attribute is less than 50 are imported
}

// A member import imports a single named member
// rather than all members of a package.
package AutomotiveLibrary {
    part def Engine;
    part def Wheel;
}

package VehicleDesign {
    import AutomotiveLibrary::Engine;
    // Only Engine is imported; Wheel is not visible
}

// An alias import gives a locally-scoped name to
// an imported member, avoiding name collisions.
package AutomotiveLibrary {
    part def InternalCombustionEngine;
}

package VehicleDesign {
    import AutomotiveLibrary::InternalCombustionEngine as ICEngine;
    // Now accessible as 'ICEngine' within VehicleDesign
}

// An element filter constrains a package so that
// only elements satisfying the condition are exposed.
// The filter applies to all imports of this package.
// (Element: Package with ElementFilterMembership)
package AutomotiveLibrary {
    filter @DetailLevel >= 2;
    // Only elements whose metadata DetailLevel >= 2
    // will be visible when this package is imported

    part def Engine { @DetailLevel = 3; }
    part def Sketch  { @DetailLevel = 1; }
}