<div dir="ltr">The type of (.)<div><br></div><div><font face="monospace, monospace"> (.) :: (b -> c) -> (a -> b) -> a -> c</font></div><div><font face="monospace, monospace"><br></font></div>Means that "last' [1,2,3]" should be a function, which it isn't<div>You can instead try,</div><div><br></div><div><font face="monospace, monospace"> main = (print . last') [1,2,3]</font></div><div><font face="monospace, monospace"><br></font></div>Or equivalently,<div><font face="monospace, monospace"><br></font></div><div><font face="monospace, monospace"> main = print . last' $ [1,2,3]</font></div></div><div class="gmail_extra"><br><div class="gmail_quote">On 12 May 2015 at 18:06, Roelof Wobben <span dir="ltr"><<a href="mailto:r.wobben@home.nl" target="_blank">r.wobben@home.nl</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000">
<div>Thanks all. <br>
<br>
I have now this : <br><span class="">
<br>
-- | The main entry point.<br></span>
last' :: [a] -> Maybe a<br>
last' [] = Nothing<br>
last' [x] = Just x <br>
last' (_:xs) = last' xs<br>
<br>
<br>
main = print . last' [1,2,3]<br>
<br>
but I see this message about main : <br>
<br>
<i>
GHC threw an exception : Couldn't match expected type
‘<a href="http://GHC.Types.IO" target="_blank">GHC.Types.IO</a> a0’ with actual type ‘a1 -> <a href="http://GHC.Types.IO" target="_blank">GHC.Types.IO</a> ()’
<br>
<br>
I work wih the fpcomplete and they demand a main in the code .<br>
<br>
Roelof<br>
<br>
</i><br>
<br>
<br>
Nicolas SCHOEMAEKER schreef op 12-5-2015 om 11:45:<br>
</div>
<blockquote type="cite"><div><div class="h5">
<p dir="ltr">Hi</p>
<p dir="ltr">In your definition, you seem to have forgotten the
case when your list is empty.<br>
[x] won't bind on [].</p>
<p dir="ltr">Regards,<br>
Nicolas SCHOEMAEKER</p>
<p dir="ltr">(<i>This email was composed from a mobile phone,
please</i><i> excuse</i><i> any resulting mistakes</i>)</p>
<p dir="ltr">Web, Cloud Computing & WebRTC developer<br>
Haskell Programmer<br>
Artificial Intelligence & Robotics enthusiast</p>
<div class="gmail_quote">On May 12, 2015, at 11:40 AM, Kim-Ee Yeoh
<<a href="mailto:ky3@atamo.com" target="_blank">ky3@atamo.com</a>> wrote:
<blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div dir="ltr">
<div class="gmail_extra"><br>
<div class="gmail_quote">On Tue, May 12, 2015 at 1:42 PM,
Roelof Wobben <span dir="ltr"><<a href="mailto:r.wobben@home.nl" target="_blank">r.wobben@home.nl</a>></span>
wrote:<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span> -- | The main entry point.<br>
last' :: [a] -> a <br>
</span> last' [x] = x <br>
<span> last' (x:xs) = last xs</span></blockquote>
</div>
<br>
</div>
<div class="gmail_extra">Notice that the last line does no
recursion: it invokes the Prelude's definition of last.<br>
</div>
<div class="gmail_extra"><br clear="all">
<div>
<div>-- Kim-Ee</div>
</div>
</div>
</div>
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<br></blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><div>Regards</div><div dir="ltr"><div><br></div><div>Sumit Sahrawat</div></div></div></div></div></div></div>
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