On Fri, Mar 4, 2011 at 07:01, wren ng thornton
where the annotation of MergeAnn is merged with the previous annotation up the tree (via mappend), thus allowing for annotations to be inherited and modified incrementally based on the Monoid instance; whereas the NewAnn constructor uses the annotation directly, overriding any contextual annotations. This can be helpful to reduce the amount of duplication in the AST, though how helpful will depend on how you plan to use/generate the ASTs.
To handle this situation, I thought I'd leave it in the hands of the user (who will be me later) to use Data.Foldable.fold (or not) to arrive at the annotation when building up their tree of statements. I don't anticipate a problem with this but I may not use monoidal annotations on this AST for some time. (I anticipate using comments and raw text inclusions in the near future.) -- Jason Dusek Linux User #510144 | http://counter.li.org/