If you're operating at the AST level, you don't need range deletes to make the merge result work. In my head I'm imagining a document (at the top level) being a

If you're operating at the AST level, you don't need range deletes to make the merge result work. In my head I'm imagining a document (at the top level) being a list of functions. Deleting two functions is expressed as deleting the AST node for the function definitions from that list. You don't need a range delete operator to do that - you just delete both function subtrees explicitly.