From a9b35266167585131c20f8d534aece849e501487 Mon Sep 17 00:00:00 2001
From: Mart Lubbers <mart@martlubbers.net>
Date: Fri, 11 Dec 2020 10:03:23 +0100
Subject: [PATCH] 11.2 and cleanup

---
 11/one.icl | 45 +++++++++++++++++++++++++++------------------
 1 file changed, 27 insertions(+), 18 deletions(-)

diff --git a/11/one.icl b/11/one.icl
index 2745c1e..f96a677 100644
--- a/11/one.icl
+++ b/11/one.icl
@@ -15,28 +15,37 @@ Start w
 	# (io, w) = stdio w
 	# ls = read io
 	# ls = {l\\l<-ls}
-	= one ls
+	= (one ls, two ls)
 
-instance == {#String} where
-	(==) l r = and [l==r\\l<-:l & r<-:r]
+one = numOccupied o cell isOccupied ((==)0) ((<=)4)
+two = numOccupied o cell seeOccupied ((==)0) ((<=)5)
 
-one :: {#String} -> Int
-one ls = length [()\\r<-:cell ls, c<-:r | c == '#']
+isOccupied :: Int Int Int Int {#String} -> Bool
+isOccupied x y dx dy ls = seat (x+dx) (y+dy) ls == '#'
 
-cell :: !{#String} -> {#String}
-cell ls = let ls` = step ls in if (ls` == ls) ls (cell ls`)
+seeOccupied :: Int Int Int Int {#String} -> Bool
+seeOccupied x y dx dy ls = case seat (x+dx) (y+dy) ls of
+	'#' = True
+	'L' = False
+	'-' = False
+	'.' = seeOccupied (x+dx) (y+dy) dx dy ls
 
-step :: !{#String} -> {#String}
-step ls = {{step` x y\\x<-[0..size ls.[0] - 1]}\\y<-[0..size ls - 1]}
+numOccupied :: {#String} -> Int
+numOccupied ls = length [()\\r<-:ls, c<-:r | c == '#']
+
+cell :: (Int Int Int Int {#String} -> Bool) (Int -> Bool) (Int -> Bool) {#String} -> {#String}
+cell lookfun live die ls
+	# ls` = {{step x y\\x<-[0..size ls.[0] - 1]}\\y<-[0..size ls - 1]}
+	= if (and [l==r\\l<-:ls` & r<-:ls]) ls (cell lookfun live die ls`)
 where
-	step` :: Int Int -> Char
-	step` x y = case ls.[y,x] of
+	step x y = case ls.[y,x] of
 		'.' = '.'
-		'L' = if (occupied == 0) '#' 'L'
-		'#' = if (occupied >= 4) 'L' '#'
+		'L' = if (live numOccupied) '#' 'L'
+		'#' = if (die numOccupied) 'L' '#'
 	where
-		occupied = length [()\\dx<-[-1..1], dy<-[-1..1] | not (dx == 0 && dy == 0) && not (empty (x+dx) (y+dy))]
-	empty :: Int Int -> Bool
-	empty x y
-		| x < 0 || x >= size ls.[0] || y < 0 || y >= size ls = True
-		= ls.[y,x] <> '#'
+		numOccupied = length [()\\dx<-[-1..1], dy<-[-1..1] | not (dx == 0 && dy == 0) && lookfun x y dx dy ls]
+
+seat :: Int Int {#String} -> Char
+seat x y ls
+	| x < 0 || x >= size ls.[0] || y < 0 || y >= size ls = '-'
+	= ls.[y,x]
-- 
2.20.1