R2RML: generating subject's class from input data

Hi all,
Currently the rr:class predicate of the rr:SubjectMapClass only let you define the type of the instance by providing a static IRI of a rdfs:Class. I propose that we add rr:classColumn and rr:classTemplate to generate the IRI of the class at runtime. 

Example :

DB:

ORGs:
| OrganizationName  |      Type       |
----------------------------------------------
| A                                 |   Company  |
| B                                 |  NGO            |
| C                                 |  NPO            |


R2RML:

<TripleMap1> 
	a rr:TripleMap;
	rr:tableName "ORGs";
        rr:subjectMap [
		rr:template "http://example.com/resource/{OrganizationName}" ;
		rr:termType "IRI";
		rr:classTemplate "http://example.com/ontology/{Type}"';
	];
.


Cheers,
Alex