-- ints.hs: conjuring functions over lists of ints
--
-- Copyright (C) 2021 Rudy Matela
-- Distributed under the 3-Clause BSD licence (see the file LICENSE).
import Conjure
second :: [Int] -> Int
second [x,y] = y
second [x,y,z] = y
second [x,y,z,w] = y
third :: [Int] -> Int
third [x,y,z] = z
third [x,y,z,w] = z
sum' :: [Int] -> Int
sum' [x] = x
sum' [x,y] = x+y
sum' [x,y,z] = x+y+z
product' :: [Int] -> Int
product' [x] = x
product' [x,y] = x*y
product' [x,y,z] = x*y*z
main :: IO ()
main = do
conjure "second" (second :: [Int] -> Int) background
conjure "third" (third :: [Int] -> Int) background
conjure "sum" (sum' :: [Int] -> Int) background
conjure "product" (product' :: [Int] -> Int) background
conjureWithMaxSize 4 "sum" (sum' :: [Int] -> Int) backgroundWithFold
conjureWithMaxSize 4 "product" (product' :: [Int] -> Int) backgroundWithFold
background :: [Expr]
background =
[ val (0 :: Int)
, val (1 :: Int)
, value "+" ((+) :: Int -> Int -> Int)
, value "*" ((*) :: Int -> Int -> Int)
, value "null" (null :: [Int] -> Bool)
, value "head" (head :: [Int] -> Int)
, value "tail" (tail :: [Int] -> [Int])
]
backgroundWithFold :: [Expr]
backgroundWithFold =
value "foldr" (foldr :: (Int -> Int -> Int) -> Int -> [Int] -> Int)
: background
-- sum xs = if null xs then 0 else head xs + sum (tail xs)
-- product xs = if null xs then 1 else head xs * product (tail xs)
-- 1 2 3 4 5 6 7 8 9 10 symbols