Condense rules with 'or' filters

The example style below will result in an XML file with 9 separate rules. But Mapnik XML supports 'or' in filters like ([type] = 'foo' or [type] = 'bar') and it really only needs to be one rule.

Ideally Carto could just condense these automatically, but alternatively there could be some kind of key in value1, value2, ... syntax. Thoughts?

#areas {
  [type='camp_site'],
  [type='common'],
  [type='national_park'],
  [type='nature_reserve'],
  [type='park'],
  [type='protected_area'],
  [type='recreation_ground'],
  [type='village_green'],
  [type='zoo'] {
    polygon-fill: green;
  }
}

<Style name="areas" filter-mode="first" >
  <Rule>
    <Filter>([type] = 'camp_site')</Filter>
    <PolygonSymbolizer fill="#008000" />
  </Rule>
  <Rule>
    <Filter>([type] = 'common')</Filter>
    <PolygonSymbolizer fill="#008000" />
  </Rule>
  <Rule>
    <Filter>([type] = 'national_park')</Filter>
    <PolygonSymbolizer fill="#008000" />
  </Rule>
  <Rule>
    <Filter>([type] = 'nature_reserve')</Filter>
    <PolygonSymbolizer fill="#008000" />
  </Rule>
  <Rule>
    <Filter>([type] = 'park')</Filter>
    <PolygonSymbolizer fill="#008000" />
  </Rule>
  <Rule>
    <Filter>([type] = 'protected_area')</Filter>
    <PolygonSymbolizer fill="#008000" />
  </Rule>
  <Rule>
    <Filter>([type] = 'recreation_ground')</Filter>
    <PolygonSymbolizer fill="#008000" />
  </Rule>
  <Rule>
    <Filter>([type] = 'village_green')</Filter>
    <PolygonSymbolizer fill="#008000" />
  </Rule>
  <Rule>
    <Filter>([type] = 'zoo')</Filter>
    <PolygonSymbolizer fill="#008000" />
  </Rule>
</Style>