%% my $default = { color => '#000000', size => 14 };
%% format(basic => $default.merge({bold => true(),align => 'left'}));

{
   "selection"  : 0,
   "worksheets" : [
      {
         "column_widths" : [ 14.6, 18.5, 15.8, 12.2 ],
         "name"          : "Merge Report 1",
         "selection"     : [ 1, 9 ],
         "row_heights"   : [ 25, 18, 18, 18 ],
         "cells"         : [
            %% for $headers -> $header {
            [
               [% c($header.value1, "basic") %],
               [% c($header.value2, "basic") %],
               [% c($header.value3, "basic") %],
               [% c($header.value4, "basic") %]
            ],
            %% }
            %% for $rows -> $row {
            [
               [% c($row.value1, "basic", "number") %],
               [% c($row.value2, "basic", "number") %],
               [% c($row.value3, "basic", "number") %],
               [% c($row.value4, "basic", "number") %]
            ],
            %% }
            []
         ],
         "merge" : [
            [% merge('A1:D1', 'Merged Header', 'basic', 'string') %],
            [% merge(
                   'A4:D4',
                   $rows.map(-> $a {$a.value1}).reduce(-> $a,$b {$a + $b}),
                   'basic',
                   'number',
                   formula => 'SUM(A2:A3)'
               ) %]
         ]
      }
   ]
}