{"id":15,"date":"2007-07-26T21:52:17","date_gmt":"2007-07-27T04:52:17","guid":{"rendered":"http:\/\/www.elbeno.com\/haskell_soe_blog\/?p=15"},"modified":"2008-01-07T21:49:42","modified_gmt":"2008-01-08T05:49:42","slug":"exercise-51","status":"publish","type":"post","link":"https:\/\/www.elbeno.com\/haskell_soe_blog\/?p=15","title":{"rendered":"Exercise 5.1"},"content":{"rendered":"<p>Recall the definitions from <a href=\"http:\/\/www.elbeno.com\/haskell_soe_blog\/?p=8\">Exercise 2.3<\/a>.<\/p>\n<pre lang=\"haskell\">area' :: Shape -> Float\r\narea' (Polygon (v1:vs)) = let arealist = map (\\(v2, v3) -> triArea v1 v2 v3)\r\n                                         (zip vs (tail vs))\r\n                          in foldl (+) 0 arealist<\/pre>\n<p><tt>(zip vs (tail vs))<\/tt> turns out to be a handy idiom.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Recall the definitions from Exercise 2.3. area&#8217; :: Shape -> Float area&#8217; (Polygon (v1:vs)) = let arealist = map (\\(v2, v3) -> triArea v1 v2 v3) (zip vs (tail vs)) in foldl (+) 0 arealist (zip vs (tail vs)) turns out to be a handy idiom.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[],"_links":{"self":[{"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=\/wp\/v2\/posts\/15"}],"collection":[{"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=15"}],"version-history":[{"count":0,"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=\/wp\/v2\/posts\/15\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=15"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=15"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=15"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}