From: Jim Pryor Date: Sun, 3 Oct 2010 01:51:02 +0000 (-0400) Subject: library tweak X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=commitdiff_plain;h=273f2590356318a9d496b49b48af330711382a3c library tweak Signed-off-by: Jim Pryor --- diff --git a/lambda_library.mdwn b/lambda_library.mdwn index 289b2843..f0b4f441 100644 --- a/lambda_library.mdwn +++ b/lambda_library.mdwn @@ -65,7 +65,7 @@ and all sorts of other places. Others of them are our own handiwork. ; more efficient reverse builds a left-fold instead ; (make_left_list a (make_left_list b (make_left_list c empty)) ~~> \f z. f c (f b (f a z)) let reverse = (\make_left_list lst. lst make_left_list empty) (\h t f z. t f (f h z)) in - ; zip [a;b;c] [x; y; z] ~~> [(a,x);(b,y);(c,z)] + ; zip [a;b;c] [x;y;z] ~~> [(a,x);(b,y);(c,z)] let zip = \left right. (\base build. reverse left build base (\x y. reverse x)) ; where base is (make_pair empty (map (\h u. u h) right))