From da663511f7a21a7fbb787ced3b727bd5187e033a Mon Sep 17 00:00:00 2001
From: Vivianne Langdon <puttabutta@gmail.com>
Date: Mon, 3 Jul 2023 01:09:56 -0700
Subject: [PATCH] Cleanup and proper win checking

---
 gib-gab-gob/game.scm | 57 ++++++++++++++++++++------------------------
 1 file changed, 26 insertions(+), 31 deletions(-)

diff --git a/gib-gab-gob/game.scm b/gib-gab-gob/game.scm
index 65e66a3..9b44fd7 100644
--- a/gib-gab-gob/game.scm
+++ b/gib-gab-gob/game.scm
@@ -20,18 +20,18 @@
 
   (methods
    ;; The peer is telling us about the turn it took.
-   [(peer-turn! coords)
+   [(peer-turn! x y)
     (if (not my-turn?)
         (begin
-          (board-choose! board peer-mark coords)
+          (board-choose! board peer-mark x y)
           (set! my-turn? (not my-turn?))
           (board-display board))
         (error "It's my turn!"))]
    ;; TODO: This needs to go somewhere else so the peer can't move for us!
-   [(my-turn! coords)
+   [(my-turn! x y)
     (if my-turn?
         (begin
-          (board-choose! board mark coords)
+          (board-choose! board mark x y)
           (set! my-turn? (not my-turn?))
           (board-display board))
         (error "It's not my turn."))]))
@@ -41,43 +41,38 @@
 (define (make-board)
   (make-array #f ggg-size ggg-size))
 
-(define (board-ref board coords)
-  (match coords ((x y) (array-ref board y x))))
+(define (board-ref board x y)
+  (array-ref board y x))
 
-(define (board-choose! board val coords)
-  (match coords
-    ((x y)
-     (define ref (board-ref board coords))
-     (if ref
-         (error "That space is already occupied with:" ref)
-         (array-set! board val y x)))))
+(define (board-choose! board val x y)
+  (define ref (board-ref board x y))
+  (if ref
+      (error "That space is already occupied with:" ref)
+      (array-set! board val y x)))
 
 (define (board-display board)
   (define (print m) (or m " "))
-
   ;; this is .. probably messy?
   (array-slice-for-each-in-order
    1
-   (lambda (x)
-     (map (lambda (i) (format #t "[~a]" (print i)))
+   (λ (x)
+     (map (λ (i) (format #t "[~a]" (print i)))
           (array->list x))
      (format #t "\n"))
    board))
 
 (define (board-winner? board mark)
+  ;; e.g. '(0 1 2)
   (define idxs (iota ggg-size))
-  (define (row-winner? y)
-    (apply eq? mark (map (lambda (x) (board-ref board (list x y))) idxs)))
-  (define (col-winner? x)
-    (apply eq? mark (map (lambda (y) (board-ref board (list x y))) idxs)))
-  (define (diag-winner?)
-    (or
-     (apply eq? mark (map (lambda (x) (board-ref board (list x x))) idxs))
-     (apply eq? mark (map (lambda (x) (board-ref board (list x x))) idxs))))
-
-  (any (lambda (x) (eq? #t x))
-       (cons
-        (diag-winner?)
-        (append
-         (map row-winner? idxs)
-         (map col-winner? idxs)))))
+  ;; true, if any item in list is non-false
+  (define (any? l) (and (any identity l) #t))
+  ;; Iterate through iota calling fn and check if all are true
+  (define (iter-all? fn) (apply eq? mark (map fn idxs)))
+  ;; Iterate through the rows and see if any are winners
+  (define (row-winner? b)
+    (any? (map (λ (y) (iter-all? (λ (x) (board-ref b x y)))) idxs)))
+  (or (row-winner? board)
+      (row-winner? (transpose-array board 1 0))
+      ;; check the two diagonals
+      (iter-all? (λ (x) (board-ref board x x)))
+      (iter-all? (λ (x) (board-ref board x (- ggg-size x 1))))))