From 3fe95f67de118f843ec189ecfd2a6ca29adff3bf Mon Sep 17 00:00:00 2001
From: "@crashkeys.dev" <dawn@crashkeys.dev>
Date: Tue, 2 Dec 2025 23:14:04 +0100
Subject: [PATCH] wikibook: basics up to recursion.

---
 start.hs | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/start.hs b/start.hs
index 52465a2..d06efe3 100644
--- a/start.hs
+++ b/start.hs
@@ -244,3 +244,20 @@ mainName = do
   putStr "Please enter your name: "
   name <- getLine
   putStrLn (nameMessage name)
+
+-- Recursion
+fact :: (Integral n, Num n) => n -> n
+fact 0 = 1
+fact n = n * fact (n - 1)
+
+fact' n = product [1 .. n] -- Seems to define a sequence between 1 and n inclusive
+
+length' :: [a] -> Int
+length' [] = 0
+length' (item : remainder) = 1 + length' remainder
+
+doubleList [] = []
+doubleList (item : remainder) = item * 2 : doubleList remainder
+
+doubleList' :: [Integer] -> [Integer]
+doubleList' = map (* 2)
-- 
2.51.2