pruneIndex :: [PackageName] -> Index -> Index
pruneIndex packagenames = Map.filterWithKey (\key _ -> key `elem` packagenames)
pruneIndex :: [PackageName] -> Index -> Index
pruneIndex packagenames = Map.filterWithKey (\key _ -> key `elem` packagenames)
pruneIndex packagenames = Map.filterWithKey (\key _ -> key `elem` packagenames)