Table.hs

module Table where
import Data.List

t1 :: [[String]]
t1 = [ ["name", "age"]
     , ["Obama", "56"]
     , ["Elizabeth", "91"]
     , ["Josiah Edward \"Jed\" Bartlet", "76"]
     ]

-- | Print table with aligned fields, assuming a tab char completes to 8 chars
showTable :: [[String]] -> String
showTable t = intercalate "\n" . map
    (\row -> concatMap
      (\(field, n) -> field ++ replicate (n - div (length field) 8 + 1) '\t')
        (zip row maxTabsPerField)) $ t
  where maxTabsPerField =
          map ((+1) . (`div` 8)   -- get max # of tabs required
              . maximum           -- get max # of chars in the same column
              . map length)       -- get lengths of each field
              . transpose $ t     -- get columns in the same list