From 3624c712d72d246f21d4e710cec7c11e052e0326 Mon Sep 17 00:00:00 2001 From: Eugen Wissner Date: Tue, 9 Dec 2025 16:32:32 +0100 Subject: Add the haskell book --- Haskell-book/08/src/WordNumber.purs | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) create mode 100644 Haskell-book/08/src/WordNumber.purs (limited to 'Haskell-book/08/src/WordNumber.purs') diff --git a/Haskell-book/08/src/WordNumber.purs b/Haskell-book/08/src/WordNumber.purs new file mode 100644 index 0000000..5d73db5 --- /dev/null +++ b/Haskell-book/08/src/WordNumber.purs @@ -0,0 +1,30 @@ +module WordNumber where + +import Data.Array (reverse) +import Data.Maybe (Maybe(..)) +import Data.String (joinWith) +import Data.Tuple (Tuple(..)) +import Data.Unfoldable (unfoldr) +import Prelude + +digitToWord :: Int -> String +digitToWord 0 = "null" +digitToWord 1 = "one" +digitToWord 2 = "two" +digitToWord 3 = "three" +digitToWord 4 = "four" +digitToWord 5 = "five" +digitToWord 6 = "six" +digitToWord 7 = "seven" +digitToWord 8 = "eight" +digitToWord 9 = "nine" +digitToWord _ = "" + +digits :: Int -> Array Int +digits n = reverse $ unfoldr unfold n + where unfold x + | x == 0 = Nothing + | otherwise = Just (Tuple (mod x 10) (div x 10)) + +wordNumber :: Int -> String +wordNumber n = joinWith "-" $ map digitToWord (digits n) -- cgit v1.2.3