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<div class="moz-cite-prefix">Oke, <br>
<br>
So a leaf is a node which has no "branch"<br>
<br>
I have made a exercise where I have to made the logMessages. <br>
Now I have to turn them into a tree <br>
<br>
Where does the second entry goes then ?<br>
<br>
Roelof<br>
<br>
<br>
Konstantine Rybnikov schreef op 26-2-2015 om 14:56:<br>
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cite="mid:CAAbahfQO5o+Db_qy_B+vb3E6WWb1bdeQBmpAPa6E-5TwTjerjg@mail.gmail.com"
type="cite">
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<div>Hi Roelof,<br>
<br>
</div>
I think you misunderstood it.<br>
<br>
</div>
<div>There are two things here: types and values
(value-constructors). They exist in different world,
not touching each other.<br>
<br>
</div>
<div>In Haskell, you define a type as:<br>
<br>
</div>
<div>data <Type_Name> =
<ValueConstructor_Name> <Type_Name>
<Type_Name> <Type_Name><br>
<br>
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<div>You can create values as:<br>
<br>
</div>
<div>let varName = <ValueConstructor_Name>
<Value> <Value> <Value><br>
<br>
</div>
<div>You need to put <Value> of some type, not
type name itself in place of those <Value>s.<br>
<br>
</div>
<div>So, with datatype you provided, you have two
data-constructors:<br>
<br>
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<div>Leaf<br>
<br>
</div>
<div>and<br>
<br>
</div>
<div>Node <val> <val> <val><br>
<br>
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<div>You can create a leaf:<br>
<br>
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<div>let leaf = Leav<br>
<br>
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<div>or a node:<br>
<br>
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<div>let node = Node Leaf "msg" Leaf<br>
<br>
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<div>You can see that Node is a data-constructor that
takes 3 values, not type-names as it's parameters.<br>
<br>
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<div>Hope this helps.<br>
</div>
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<div class="gmail_extra"><br>
<div class="gmail_quote">On Thu, Feb 26, 2015 at 3:21 PM, Roelof
Wobben <span dir="ltr"><<a moz-do-not-send="true"
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">Hello,<br>
<br>
Suppose we have this definition of a tree :<br>
<br>
data MessageTree = Leaf<br>
| Node MessageTree LogMessage MessageTree<br>
deriving (Show, Eq)<br>
<br>
let Message = LogMessage "E 1 this is a test error"<br>
let Message = LogMessage "e 2 this is the second test error
"<br>
<br>
As I understand it right I can make the first entry like
this : first_entry = Node Messagetree Message Messagetree<br>
<br>
And the second one like this second_entry = Node Message
Messagetree Message2 Messagetree ??<br>
<br>
Roelof<br>
<br>
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