anchor.diff:  
   %% Compile a single selection column into a fun that can extract the cell
   %% from the row.
  -% -spec compile_select_col(DDL::#ddl_v1{}, ColumnSpec::any()) ->
  -%         #single_sel_column{}.
  +-spec compile_select_col(DDL::#ddl_v1{}, ColumnSpec::any()) ->
  +        #single_sel_column{}.
   compile_select_col(DDL, {{window_agg_fn, FnName}, [FnArg1]}) ->
       case riak_ql_window_agg_fns:start_state(FnName) of
           stateless ->
  
positive.code: 
  %% Returns a one arity fun which is stateless for example pulling a field from a
  %% row.
  % -spec compile_select_col_stateless(#ddl_v1{}, selection()) ->
  %         {ColTypes::[primitive_field_type()], IsValid::true|any(), function()}.
  compile_select_col_stateless(DDL, {identifier, [<<"*">>]}) ->
      ColTypes = [X#riak_field_v1.type || X <- DDL#ddl_v1.fields],
      {ColTypes, true, fun(Row) -> Row end};
  
negative.code: }).
  
  %%
  -spec select_column_clause_folder(#ddl_v1{}, selection(), {set(), #riak_sel_clause_v1{}}) ->
          {set(), #riak_sel_clause_v1{}}.
  select_column_clause_folder(DDL, ColX, {TypeSet1, SelClause1}) ->
      #riak_sel_clause_v1{
          initial_state = InitX,
  