From 5a157d66b046a3061f92b47a02dee97e34d7df37 Mon Sep 17 00:00:00 2001
From: tA <s@p7.co.nz>
Date: Wed, 17 Jul 2019 12:28:00 +1200
Subject: [PATCH] first commit

---
 README.md | 43 +++++++++++++++++++++++++++++++++++++++++++
 week2.hs  | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 104 insertions(+)
 create mode 100644 README.md
 create mode 100644 week2.hs

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..c58c52c
--- /dev/null
+++ b/README.md
@@ -0,0 +1,43 @@
+# I'm so sorry
+
+Hoon101's Week 2 Assignment in Haskell
+
+> Create a gate that takes a noun, checks if its a cell, and if not, checks if the atom is odd or even
+
+## Running
+
+in `ghci`, load the file:
+
+```
+:load week2.hs
+```
+
+you can then run the program using the form
+
+`:t solution (nil :: X)`
+
+where `X` is either an atom or a cell, using the following syntax:
+
+`Atom`: Using Church Encoding with `(S n)` and `Z`, ie `(S (S (S Z)))` is the atom `3`
+
+`Cell`: Using `Cons x xs` and `Nil`, ie `(Cons (S Z) (Cons Z Z))` is the cell `[1 [0 0]]`
+
+## Example
+
+```
+*Main> :load week2.hs 
+[1 of 1] Compiling Main             ( week2.hs, interpreted )
+Ok, modules loaded: Main.
+
+*Main> :t solution (nil :: (S (S (S (S Z)))))
+solution (nil :: (S (S (S (S Z)))))
+   :: IsEvenAtom
+
+*Main> :t solution (nil :: (S (S (S (S (S Z))))))
+solution (nil :: (S (S (S (S (S Z))))))
+   :: IsOddAtom
+
+*Main> :t solution (nil :: (Cons (Cons (S Z) (S (S Z))) (Cons (S (S (S Z))) (S (S (S (S Z)))))))
+solution (nil :: (Cons (Cons (S Z) (S (S Z))) (Cons (S (S (S Z))) (S (S (S (S Z)))))))
+   :: IsCell
+```
diff --git a/week2.hs b/week2.hs
new file mode 100644
index 0000000..a68bad0
--- /dev/null
+++ b/week2.hs
@@ -0,0 +1,61 @@
+{-# OPTIONS_GHC -fno-warn-missing-methods #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE FunctionalDependencies #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE UndecidableInstances #-}
+
+nil = undefined
+
+data True
+data False
+
+data S n
+data Z
+
+data Nil
+data Cons h t
+
+data IsCell
+data IsOddAtom
+data IsEvenAtom
+
+class Not t b | t -> b
+instance Not True False
+instance Not False True
+
+class And a b r | a b -> r
+instance And True True True
+instance And True False False
+instance And False True False
+instance And False False False
+
+class If c t f r | c t f -> r
+instance If True t f t
+instance If False t f f
+
+class IsEven a b | a -> b
+instance IsEven Z True
+instance IsEven (S Z) False
+instance (IsEven n r)
+   => IsEven (S (S n)) r
+instance IsEven (Cons xs x) False
+
+class Wutpam t b | t -> b
+instance Wutpam Z True
+instance Wutpam (S n) True
+instance Wutpam Nil False
+instance Wutpam (Cons x xs) False
+
+class Wutket t b | t -> b
+instance (Wutpam t b, Not b r)
+   => Wutket t r
+
+class Solution n r | n -> r
+   where solution :: n -> r
+instance ( Wutket n c
+         , Not c a
+         , IsEven n m
+         , If m IsEvenAtom IsOddAtom e
+         , If c IsCell e o
+         )
+   => Solution n o where solution = nil