more assignment3 name cleanup

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

diff --git a/assignment3.mdwn b/assignment3.mdwn
index 8c22dfa..df06d52 100644 (file)
--- a/assignment3.mdwn
+++ b/assignment3.mdwn
@@ -14,32 +14,30 @@ Recall that version 1 style lists are constructed like this (see
        let false = \x y. y in
        let and = \l r. l (r true false) false in
 
        let false = \x y. y in
        let and = \l r. l (r true false) false in
 

-       ; version 1 lists

        let make_pair = \f s g. g f s in
        let make_pair = \f s g. g f s in

-       let fst = true in
-       let snd = false in
+       let get_fst = true in
+       let get_snd = false in

        let empty = make_pair true junk in
        let empty = make_pair true junk in

-       let isempty = \x. x fst in
+       let isempty = \x. x get_fst in

        let make_list = \h t. make_pair false (make_pair h t) 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
-
+       let head = \l. isempty l err (l get_snd get_fst) in
+       let tail = \l. isempty l err (l get_snd get_snd) in
+       

        ; a list of numbers to experiment on
        let mylist = make_list 1 (make_list 2 (make_list 3 empty)) in
        ; a list of numbers to experiment on
        let mylist = make_list 1 (make_list 2 (make_list 3 empty)) in

-
-       ; a fixed-point combinator for defining recursive functions
-       let Y = \f. (\h. f (h h)) (\h. f (h h)) in
-
+       

        ; church numerals
        let iszero = \n. n (\x. false) true in
        let succ = \n s z. s (n s z) in
        ; church numerals
        let iszero = \n. n (\x. false) true in
        let succ = \n s z. s (n s z) in

-       let mult = \m n s. m (n s) in
-       let length = Y (\length l. isempty l 0 (succ (length (tail l)))) in
-       let pred = \n. iszero n 0 (length (tail (n (\p. make_list junk p) empty)))
-       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
        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
+       

        eq 2 2 yes no
 
 
        eq 2 2 yes no
 
 

diff --git a/assignment_3_evaluator.mdwn b/assignment_3_evaluator.mdwn
index c0af5d0..496003d 100644 (file)
--- a/assignment_3_evaluator.mdwn
+++ b/assignment_3_evaluator.mdwn
@@ -6,13 +6,13 @@ 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 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 get\_fst = true in
+let get\_snd = false in

 let empty = make\_pair true junk in
 let empty = make\_pair true junk in

-let isempty = \x. x fst in
+let isempty = \x. x get\_fst in

 let make\_list = \h t. make\_pair false (make\_pair h t) 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
+let head = \l. isempty l err (l get\_snd get\_fst) in
+let tail = \l. isempty l err (l get\_snd get\_snd) in

 ;
 ; a list of numbers to experiment on
 let mylist = make\_list 1 (make\_list 2 (make\_list 3 empty)) in
 ;
 ; a list of numbers to experiment on
 let mylist = make\_list 1 (make\_list 2 (make\_list 3 empty)) in


@@ -32,6 +32,8 @@ let length = Y (\length l. isempty l 0 (succ (length (tail l)))) in
 ;
 ; synonyms
 let makePair = make\_pair in
 ;
 ; synonyms
 let makePair = make\_pair in

+let fst = get\_fst in
+let snd = get\_snd in

 let nil = empty in
 let isNil = isempty in
 let makeList = make\_list in
 let nil = empty in
 let isNil = isempty in
 let makeList = make\_list in