<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On 12 May 2015 at 20:14, 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:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
  
    
  
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    <div>Thanks, <br>
      <br>
      The right solution was this : <br>
      <br>
      init' (x:xs) = Just (x:fromMaybe xs (init' xs))<br>
      <br>
      if I understand it right x:fromMaybe xs takes care that from xs
      the just or Nothing is removed ?<br>
      <br></div></div></blockquote><div><br></div>Trying it out in ghci,<div><br></div><div>fromMaybe [1,2] Nothing == [1,2]</div><div>fromMaybe [1,2] Just [3] == [3]</div><div><br></div><div>It seems like that should indeed work.</div><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div bgcolor="#FFFFFF" text="#000000"><div>
      Roelof<br>
      <br>
      <br>
      <br>
      Alexey Shmalko schreef op 12-5-2015 om 16:33:<br>
    </div><div><div class="h5">
    <blockquote type="cite">
      <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" target="_blank">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" target="_blank">r.wobben@home.nl</a>> wrote:<br>
        <blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style: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:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
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                    <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:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style: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>
                            </div>
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                    <br>
                  </div>
                  <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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<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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