{"id":5,"date":"2007-07-24T21:55:31","date_gmt":"2007-07-25T04:55:31","guid":{"rendered":"http:\/\/www.elbeno.com\/haskell_soe_blog\/?p=5"},"modified":"2008-01-07T21:36:22","modified_gmt":"2008-01-08T05:36:22","slug":"exercise-13","status":"publish","type":"post","link":"https:\/\/www.elbeno.com\/haskell_soe_blog\/?p=5","title":{"rendered":"Exercise 1.3"},"content":{"rendered":"<pre lang=\"haskell\">simple x y z = x * (y + z)<\/pre>\n<p>From what we have learnt so far:<\/p>\n<pre lang=\"haskell\">[(2, 3), (4, 5)] :: [(Integer, Integer)]\r\n['z', 42] :: {- Error: different types cannot be mixed in a list -}\r\n('z', -42) :: (Char, Integer)\r\nsimple 'a' 'b' 'c' :: {- Error: simple cannot be called with Char types -}\r\n(simple 1 2 3, simple) :: (Integer, Integer -> Integer -> Integer -> Integer)<\/pre>\n<p>Hugs gives a slightly more general type for these:<\/p>\n<pre lang=\"haskell\">[(2, 3), (4, 5)] :: (Num a, Num b) => [(a,b)]\r\n('z', -42) :: Num a => (Char,a)\r\n(simple 1 2 3, simple) :: (Num a, Num b) => (b,a -> a -> a -> a)<\/pre>\n","protected":false},"excerpt":{"rendered":"<p>simple x y z = x * (y + z) From what we have learnt so far: [(2, 3), (4, 5)] :: [(Integer, Integer)] [&#8216;z&#8217;, 42] :: {- Error: different types cannot be mixed in a list -} (&#8216;z&#8217;, -42) :: (Char, Integer) simple &#8216;a&#8217; &#8216;b&#8217; &#8216;c&#8217; :: {- Error: simple cannot be called with [&hellip;]<\/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\/5"}],"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=5"}],"version-history":[{"count":0,"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=\/wp\/v2\/posts\/5\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=5"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}