From: jim Date: Mon, 6 Apr 2015 14:03:37 +0000 (-0400) Subject: change x,y to n,m X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=commitdiff_plain;h=67cb14b0d6067d3024d34c8e72febd07b8f33b3f change x,y to n,m --- diff --git a/exercises/assignment8-9.mdwn b/exercises/assignment8-9.mdwn index c41ee9ba..529811cd 100644 --- a/exercises/assignment8-9.mdwn +++ b/exercises/assignment8-9.mdwn @@ -17,17 +17,17 @@ relationships, as in See her 1999 paper for details. Here is [[code for the arithmetic tree Chris presented in week 8|code/arith1.ml]]. It computes -`\x. (+ 1 (* (/ 6 x) 4))`. Your task is to modify it to compute -`\x y. (+ 1 (* (/ 6 x) y))`. You will need to modify five lines. +`\n. (+ 1 (* (/ 6 n) 4))`. Your task is to modify it to compute +`\n m. (+ 1 (* (/ 6 n) m))`. You will need to modify five lines. The first one is the type of a boxed int. Instead of `type num = int -> int`, you'll need type num = int -> int -> int The second and third are the definitions of `mid` and `map2`. The fourth -is the one that encodes the variable `x`, the line that begins `(Leaf -(Num (fun x -> ...`. The fifth line you need to modify is the one -that replaces "4" with "y". When you have these lines modified, +is the one that encodes the variable `n`, the line that begins `(Leaf +(Num (fun n -> ...`. The fifth line you need to modify is the one +that replaces "4" with "m". When you have these lines modified, you should be able to execute the following expression: # match eval t2 with Leaf (Num f) -> f 2 4;;