example.hs

print_table [left, right, right, right] ["Ore", "Value/m3", "Cost/m3", "Hourly Value"] (map prep_row $ sortBy most_valuable $ zip4 types values costs hourly)

Util.hs

import Data.List
import Text.PrettyPrint.Boxes as B

print_table :: [Alignment] -> [String] -> [[String]] -> IO ()
print_table aligns titles rows = printBox $ hsep 2 B.left (map (\(align, title, col) -> vcat center2 [text title, vcat align $ map text col]) $ zip3 aligns titles (transpose rows))

left = B.left
right = B.right
center = B.center2