From 5ed8a6c84fad085dfab0bb91621c5a887f8802ef Mon Sep 17 00:00:00 2001 From: Jim Pryor Date: Sun, 3 Oct 2010 16:31:55 -0400 Subject: [PATCH] week3 evaluator fix Signed-off-by: Jim Pryor --- assignment_3_evaluator.mdwn | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/assignment_3_evaluator.mdwn b/assignment_3_evaluator.mdwn index 9207c058..c0af5d01 100644 --- a/assignment_3_evaluator.mdwn +++ b/assignment_3_evaluator.mdwn @@ -13,10 +13,10 @@ let isempty = \x. x fst in let make\_list = \h t. make\_pair false (make\_pair h t) in let head = \l. isempty l err (l snd fst) in let tail = \l. isempty l err (l snd snd) in - +; ; a list of numbers to experiment on let mylist = make\_list 1 (make\_list 2 (make\_list 3 empty)) in - +; ; church numerals let iszero = \n. n (\x. false) true in let succ = \n s z. s (n s z) in @@ -24,12 +24,12 @@ let mul = \m n s. m (n s) in let pred = \n. iszero n 0 (length (tail (n (\p. make\_list junk p) empty))) in let leq = \m n. iszero(n pred m) in let eq = \m n. and (leq m n)(leq n m) in - +; ; a fixed-point combinator for defining recursive functions let Y = \f. (\h. f (h h)) (\h. f (h h)) in - +; let length = Y (\length l. isempty l 0 (succ (length (tail l)))) in - +; ; synonyms let makePair = make\_pair in let nil = empty in @@ -37,7 +37,7 @@ let isNil = isempty in let makeList = make\_list in let isZero = iszero in let mult = mul in - +; length (tail mylist) -- 2.11.0