From: Jim Pryor <profjim@jimpryor.net>
Date: Sun, 3 Oct 2010 20:27:10 +0000 (-0400)
Subject: week3 evaluator fix
X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=commitdiff_plain;h=1842b3259860fe518d995153209eb6e3cb6d1123

week3 evaluator fix

Signed-off-by: Jim Pryor <profjim@jimpryor.net>
---

diff --git a/assignment_3_evaluator.mdwn b/assignment_3_evaluator.mdwn
index 7a453e64..64bebb58 100644
--- a/assignment_3_evaluator.mdwn
+++ b/assignment_3_evaluator.mdwn
@@ -1,46 +1,45 @@
 Here are the definitions pre-loaded for working on assignment 3:
 
-<textarea id="INPUT" style="border: 2px solid black;
-color: black; font-family: monospace; height: 3in;
-overflow: auto; padding: 0.5em; width: 100%;">
-; booleans
-let true = \x y. x in
-let false = \x y. y in
-let and = \l r. l (r true false) false in
-let make_pair = \f s g. g f s in
-let fst = true in
-let snd = false in
-let empty = make_pair true junk in
-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
-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
-let isNil = isempty in
-let makeList = make_list in
-let isZero = iszero in
-let mult = mul in
-;
-length (tail mylist)
+<textarea id="INPUT" style="border: 2px solid black; color: black; font-family:
+monospace; height: 3in; overflow: auto; padding: 0.5em; width: 100%;">
+	; booleans
+	let true = \x y. x in
+	let false = \x y. y in
+	let and = \l r. l (r true false) false in
+	let make_pair = \f s g. g f s in
+	let fst = true in
+	let snd = false in
+	let empty = make_pair true junk in
+	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
+	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
+	let isNil = isempty in
+	let makeList = make_list in
+	let isZero = iszero in
+	let mult = mul in
+
+	length (tail mylist)
 </textarea>
 <input id="PARSE" value="Normalize" type="button">
 <input id="ETA" type="checkbox">do eta-reductions too