First i want to thank all the persons who responded me yesterday to help me. Thanks! I am so happy with with your <span style="font-family:arial,sans-serif;font-size:13px;white-space:nowrap;background-color:rgb(255,255,255)">friendliness</span>.<div>
So i have other beginners question:</div><div><br></div><div>Now i want a improved version of my<font color="#000099"><b> intercalate</b></font>. Now i want to call a function with two [t][t] and obtain another one which have only</div>
<div>even elements, even because:</div><div><ul><li>[1,2,3,3,4][6] and the ouput [1,6]</li><li>[1,2,3,4][5,6,7] output [1,5,2,6,3,7]</li></ul><div>I tried it:</div></div><div><br></div><div><div><font color="#000099"><b>intercalate :: (Eq t) => [t] -> [t] -> [t]</b></font></div>
<div><font color="#000099"><b>intercalate (x:xs) (y:ys)</b></font></div><div><font color="#000099"><b><span class="Apple-tab-span" style="white-space:pre"> </span>| xt == []<span class="Apple-tab-span" style="white-space:pre"> </span>= []</b></font></div>
<div><font color="#000099"><b><span class="Apple-tab-span" style="white-space:pre"> </span>| yt == []<span class="Apple-tab-span" style="white-space:pre"> </span>= []</b></font></div><div><font color="#000099"><b><span class="Apple-tab-span" style="white-space:pre"> </span>| otherwise<span class="Apple-tab-span" style="white-space:pre"> </span>= x : y : intercalate xs ys</b></font></div>
<div><font color="#000099"><b><span class="Apple-tab-span" style="white-space:pre"> </span>where xt=(x:xs)</b></font></div><div><font color="#000099"><b><span class="Apple-tab-span" style="white-space:pre"> </span> yt=(y:ys)</b></font></div>
<div><span class="Apple-tab-span" style="white-space:pre"> </span> </div></div><div>but i get nice error</div><div><br></div><div><div><font color="#000099"><b>*Main> intercalate [1][6]</b></font></div><div><font color="#000099"><b>[1,6*** Exception: baby.hs:(2,1)-(5,51): Non-exhaustive patterns in function intercalate</b></font></div>
<div><font color="#000099"><b><br></b></font></div><div><font color="#000099"><b>*Main> </b></font></div></div><div><br></div><div>(yes...the file's name is baby.hs)</div><div><br></div><div>Thanks in advance! (: (: (:</div>
<div>(: (:</div>