#28 support subjectIndicatorRef in parameters

[Ichiro Furusato]

currently the Variant interface includes an addParameter(Topic) method, but XTM 1.0 also permits <subjectIndicatorRef> elements as children of <parameters>, so there should probably be an addParameter(Locator) method in the API as well.

Calls to this method would add a Locator instead of a Topic. When one doesn't want to reify the subject of the parameter (such as XTM 'Display') as a Topic, this would be welcome.

[Kal Ahmed]

Logged In: YES
user_id=176992
Originator: NO

My feeling is that the underlying data model should keep all parameters as topics, otherwise it gets messy for a programmer calling getParameters to have to deal with a list of Topic and Locator objects. However, a convenience method addParameter(Locator l) could operate as follows:
1) Find a topic with subject identifier l. If found add that topic as a parameter otherwise,
2) Find a topic with source locator l. If found add that topic as a parameter otherwise,
3) Create a new topic and add l as a subject identifier then add that topic as a parameter.

(Note that step (2) is required because a topic T with subject identifier L will merge with a topic T with source locator L under topic map merging rules, so if you didn't do that step then step (3) would create a topic which would instantly get merged).