[antlr-interest] Why is the filter option incompatible with the template option?

[ToolUsr]

Hello,
    I have a Model-View pattern where the Model is an AST producing grammar  created from a parsed language (i.e. Java), which is then passed on to various tree grammar Views which filter the model for presentation. The Model is output language independent, just pure ANTLR producing the full AST representation of the file. The Views (which are filters by their nature) use actions and what not to act on the full model, and I need to have this be a template for various reasons. However, ANTLR errors out that the two options are incompatible, in a tree grammar at least. 
    This makes no sense to me, in a MVC pattern it makes sense for the model to be complete and as the heavy lifting is done in the Views, they need as much help as they can get, i.e. filtering and templates for code generation and whatnot.