Namespace prefix should be definable by a user

[sjiherzig]

Currently, the namespace prefix is implicitly assumed to be the last part of an IRI. For instance, consider the following example:

open terminology <http://jpl.nasa.gov/someTerminology> {
    extends <http://jpl.nasa.gov/anotherTerminology>

    concept Foo

    Foo extendsConcept anotherTerminology:Bar
}

where the ontology being extended from is assumed to be defined as:

open terminology <http://jpl.nasa.gov/anotherTerminology> {
    concept Bar
}

Problematic are cases where the IRI ends with the same suffix. In such cases, the prefix may no longer be unique. For instance, consider the following example:

closed terminology <http://jpl.nasa.gov/someModel> {
    extends <http://jpl.nasa.gov/someTool/metamodel>
    extends <http://jpl.nasa.gov/someOtherTool/metamodel>

    ...
}

In such cases, it is impossible to differentiate between the two ontologies being extended from.

Suggestion: add an optional specification of a namespace prefix that, if left unset, defaults back to the current strategy.

E.g., for terminology extension axioms:

TerminologyExtensionAxiom returns TerminologyExtensionAxiom:
	( annotations+=AnnotationPropertyValue )*
	'extends' (nsPrefix=STRING ':')? extendedTerminology=[TerminologyBox|ExternalReference];

This would result in syntax such as:

closed terminology <http://jpl.nasa.gov/someModel> {
    extends someToolMM : <http://jpl.nasa.gov/someTool/metamodel>
    extends someOtherToolMM : <http://jpl.nasa.gov/someOtherTool/metamodel>

    ...

    Foo extendsConcept someToolMM:MetaBar

    Bar extendsConcept someOtherToolMM:MetaFoo

    ...
}

(Note that this is just a suggestion for how to do it - whether this is the best possible syntax is up for debate)

[NicolasRouquette]

I think this is doable by adding in OML ModuleEdge an optional nsPrefix string property.

For the concrete syntax, I think '=' would make more sense than ':';, i.e.,:

closed terminology <http://jpl.nasa.gov/someModel> {
    extends someToolMM = <http://jpl.nasa.gov/someTool/metamodel>
    extends someOtherToolMM = <http://jpl.nasa.gov/someOtherTool/metamodel>

    ...

    Foo extendsConcept someToolMM:MetaBar

    Bar extendsConcept someOtherToolMM:MetaFoo

    ...
}

This is not a big deal to do; however, this will require updating all the other OML infrastructure components in Scala as well.