September 2017 Update

Task/Non-decimal-radices-Output/Haskell/non-decimal-radices-output-3.hs

@@ -0,0 +1,40 @@
+import Data.Monoid ((<>))
+import Data.Array (Array, listArray, (!))
+import Data.List (unfoldr, transpose, intercalate)
+
+-- ARBITRARY RADICES ----------------------------------------------------------
+bases :: [Int]
+bases = abs <$> [2, 7, 8, 10, 12, 16, 32]
+
+tableRows :: [[String]]
+tableRows = ((([baseDigits] <*> bases) <*>) . return) <$> [1 .. 33]
+
+digits :: Array Int Char
+digits = listArray (0, 35) (['0' .. '9'] <> ['A' .. 'Z'])
+
+baseDigits :: Int -> Int -> String
+baseDigits base
+  | base > 36 = const "Needs glyphs beyond Z"
+  | otherwise = reverse . unfoldr remQuot
+  where
+    remQuot 0 = Nothing
+    remQuot n =
+      let (q, r) = quotRem n base
+      in Just (digits ! r, q)
+
+-- TEST AND TABULATION---------------------------------------------------------
+table :: String -> [[String]] -> [String]
+table delim rows =
+  intercalate delim <$>
+  transpose
+    ((\col ->
+         let width = maximum (length <$> col)
+             justifyRight n c s = drop (length s) (replicate n c <> s)
+         in justifyRight width ' ' <$> col) <$>
+     transpose rows)
+
+main :: IO ()
+main =
+  mapM_
+    putStrLn
+    (table " " (([(show <$>), (const "----" <$>)] <*> [bases]) <> tableRows))