Parameterize AnnotationStatistics by OUTCOME_TYPE?

Right now, AnnotationStatistics only works with String outcomes. If we want it 
to be able to work with other outcome types (e.g. Boolean), then we need to add 
a type parameter. This should be pretty easy, except for this method:

  public <ANNOTATION_TYPE extends Annotation> void add(
      Collection<? extends ANNOTATION_TYPE> referenceAnnotations,
      Collection<? extends ANNOTATION_TYPE> predictedAnnotations,
      String outcomeFeatureName)

This is a convenience method that uses the annotation offsets as its "span", 
and the value of the given feature as the "outcome". However, we don't know in 
general how to convert a feature value to an OUTCOME_TYPE type. The only 
solution I see is to replace the String parameter with a 
Function<ANNOTATION_TYPE, OUTCOME_TYPE> parameter as is done in the 4 parameter 
version of add. Then users would have to manually provide 
AnnotationStatistics.annotationToFeatureValue(outcomeFeatureName) as the value 
of this parameter.

Is it worth it to allow AnnotationStatistics to be used with any arbitrary 
outcome type?

We need to decide before the 1.2 release, because AnnotationStatistics has not 
been released yet, and this is probably our last chance to make a breaking 
change.

Original issue reported on code.google.com by steven.b...@gmail.com on 31 Jul 2012 at 11:16

DrDub / cleartk

Parameterize AnnotationStatistics by OUTCOME_TYPE? #320