From 136e49c2a054047a015f86e5d5e0cc443fc63fde Mon Sep 17 00:00:00 2001
From: rhiannon morris <rhi@rhiannon.website>
Date: Tue, 6 Dec 2022 06:49:48 +0100
Subject: [PATCH] simplify all_diff

---
 day6.m | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/day6.m b/day6.m
index 75b115a..d3d71ae 100644
--- a/day6.m
+++ b/day6.m
@@ -12,22 +12,16 @@
 :- import_module list.
 :- import_module maybe.
 
-
-:- func uniq(list(T)) = list(T).
-uniq([]) = [].
-uniq([X | Xs]) = Ys :-
-  Ys0 = uniq(Xs),
-  (if member(X, Ys0) then Ys = Ys0 else Ys = [X | Ys0]).
-
-:- pred alldiff(list(T)::in) is semidet.
-alldiff(Xs) :- Xs = uniq(Xs).
+:- pred all_diff(list(T)::in) is semidet.
+all_diff([]).
+all_diff([X | Xs]) :- not member(X, Xs), all_diff(Xs).
 
 :- pred window(int::in, list(T)::in, int::out, list(T)::out) is nondet.
 window(Len, In,     0,     Out) :- take(Len, In, Out).
 window(Len, [_|In], I + 1, Out) :- window(Len, In, I, Out).
 
 :- pred start_index(int::in, list(T)::in, int::out) is cc_nondet.
-start_index(Len, Input, Index) :- window(Len, Input, Index, Out), alldiff(Out).
+start_index(Len, Input, Index) :- window(Len, Input, Index, Out), all_diff(Out).
 
 :- func length(part) = int.
 length(one) = 4.