QVT14 — How are comments persisted?

QVT supports two styles of comment, single/multi-line each of which may precede/follow the commented syntax element. (A leading new-line distinguishes a preceding from a following comment).

The QVT AS inherits a Comment element from MOF with body and annotatedElement properties. This is inadequate to distinguish the two styles or the two positions. Could be fixed by a couple of Boolean properties.

Comments may also be applied to punctuation that has no corresponding model element.

if x then y
else // must have an else
z endif

Perhaps an annotatedText is necessary to allow a comment to refer to punctuation

<comment multiline="false" prefix="false" annotatedText="else" body="must have an else"/>

Might need an annotatedIndex too for the case where the annotatedText occurs multiple times.

Since the annotatedElement is already there, it might be less klunky to anchor the markup with annotatedElement="...z..." precedingText="else", where "...z..." is the appropriate fragment to reference the z element.