<div dir="ltr">Try fromMaybe [1]. Examples<br><br><div>Prelude Data.Maybe> fromMaybe [] (Just [1,2,3])</div><div>[1,2,3]</div><div>Prelude Data.Maybe> fromMaybe [1,2,3] Nothing</div><div>[1,2,3]</div><div><br></div><div>[1]: <a href="https://hackage.haskell.org/package/base-4.8.0.0/docs/Data-Maybe.html#v:fromMaybe">https://hackage.haskell.org/package/base-4.8.0.0/docs/Data-Maybe.html#v:fromMaybe</a><br></div></div><br><div class="gmail_quote">On Tue, May 12, 2015 at 5:28 PM Roelof Wobben <<a href="mailto:r.wobben@home.nl">r.wobben@home.nl</a>> 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>Oke, <br>
<br>
And how do I do this. Haskell is a difficult one to learn,<br>
<br>
Roelof<br>
<br>
<br>
<br>
Alexey Shmalko schreef op 12-5-2015 om 16:24:<br>
</div></div><div bgcolor="#FFFFFF" text="#000000">
<blockquote type="cite">
<div dir="ltr">Before cons'ing the result of init', you should
check whether it's Just or Nothing. What you're doing now is
something along the line with 5 : Just 3 -- this won't
typecheck.<br>
</div>
<br>
<div class="gmail_quote">On Tue, May 12, 2015 at 5:22 PM Roelof
Wobben <<a href="mailto:r.wobben@home.nl" target="_blank">r.wobben@home.nl</a>> 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>Brandon Allbery schreef op 12-5-2015 om 16:16:<br>
</div>
</div>
<div bgcolor="#FFFFFF" text="#000000">
<blockquote type="cite">
<div dir="ltr">
<div class="gmail_extra">
<div class="gmail_quote">On Tue, May 12, 2015 at 10:11
AM, 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>I do not understand what you are saying to
me.<br>
<br>
I know that init produces a Maybe [a] . That
is why I did put a Just before it.<br>
</div>
</div>
</blockquote>
<div><br>
</div>
<div>You are invoking it again though, and using its
result as if it produces [a] instead of Maybe [a].</div>
</div>
<div><br>
</div>
-- <br>
<div>
<div dir="ltr">
<div>brandon s allbery kf8nh
sine nomine associates</div>
<div><a href="mailto:allbery.b@gmail.com" target="_blank">allbery.b@gmail.com</a>
<a href="mailto:ballbery@sinenomine.net" target="_blank">ballbery@sinenomine.net</a></div>
<div>unix, openafs, kerberos, infrastructure,
xmonad <a href="http://sinenomine.net" target="_blank">http://sinenomine.net</a></div>
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<div bgcolor="#FFFFFF" text="#000000"> What is then the right
way to do. I still do not understand what you are trying to
make clear to me.</div>
<div bgcolor="#FFFFFF" text="#000000"><br>
<br>
Roelof</div>
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