X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=blobdiff_plain;f=assignment8.mdwn;h=a1e0140c7ce3a996553cea799b013d3464b5f5c6;hp=814f8d5663de0c86eed5a7ebb8741ef50995e28c;hb=f1012badf41d0d6d52dc849603eaca8aeb752b0b;hpb=07e66be3b3fa7b8b843894bdcbcb181bd1757349

diff --git a/assignment8.mdwn b/assignment8.mdwn
index 814f8d56..a1e0140c 100644
--- a/assignment8.mdwn
+++ b/assignment8.mdwn
@@ -8,7 +8,7 @@
 
 		let rec move_botleft (z : 'a zipper) : 'a zipper =
 			(* returns z if the targetted node in z has no children *)
-			(* else returns move_botleft (zipper which results from moving down and left in z) *)
+			(* else returns move_botleft (zipper which results from moving down from z to the leftmost child) *)
 			_____
 			(* YOU SUPPLY THE DEFINITION *)
 
@@ -25,6 +25,8 @@
 			{tree = Root; filler = t}
 			;;
 
+	 
+
 		let make_fringe_enumerator (t: 'a tree) =
 			(* create a zipper targetting the root of t *)
 			let zstart = new_zipper t
@@ -131,28 +133,3 @@
 		(same-fringe? tree1 tree2)
 
 
-<!--
-		(define (lazy-flatten tree)
-		  (letrec ([helper (lambda (tree tailk)
-		                  (cond
-		                    [(pair? tree)
-		                      (helper (car tree) (lambda () (helper (cdr tree) tailk)))]
-		                    [else (cons tree tailk)]))])
-		    (helper tree (lambda () (list)))))
-		
-		(define (stream-equal? stream1 stream2)
-		  (cond
-		    [(and (null? stream1) (null? stream2)) #t]
-		    [(and (pair? stream1) (pair? stream2))
-		     (and (equal? (car stream1) (car stream2))
-		          (stream-equal? ((cdr stream1)) ((cdr stream2))))]
-		    [else #f]))
-		
-		(define (same-fringe? tree1 tree2)
-		  (stream-equal? (lazy-flatten tree1) (lazy-flatten tree2)))
-		
-		(define tree1 '(((1 . 2) . (3 . 4)) . (5 . 6)))
-		(define tree2 '(1 . (((2 . 3) . (4 . 5)) . 6)))
-		
-		(same-fringe? tree1 tree2)
--->