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copied!<p>Suppose you have:</p> <pre><code>myDate = Gtg 7 Jan 2013 myPerson = Person "Joe" "Bloe" myDate myEintrag = (myPerson, ???, ???) -- I don't know what Anschrift and SozNr look like </code></pre> <p>Here are some examples of how you access them:</p> <pre><code>putStrLn $ show (vorname myPerson) putStrLn $ show (nachname myPerson) let (a, _, _) = myEintrag putStrLn $ show (nachname a) let (Gtg d m y) = geburtstag a putStrLn $ show y </code></pre> <p>If you used named fields on <code>Geburtstag</code> and <code>Eintrag</code> as you did with <code>Person</code>, it might be more convenient (depending on your application). Otherwise, you have to pattern match on those fields, as I've done here.</p> <hr> <p>EDIT: You say you already have getPerson, which I assume looks something like this:</p> <pre><code>getPerson :: Eintrag -> Person getPerson (p, _, _) = p </code></pre> <p>So in my example, <code>getPerson myEintrag</code> would return <code>myPerson</code>.</p> <p>You don't need to write a function to extract the geburtstag from a person; naming the field gives you that function automatically. So <code>geburtstag (getPerson myEintrag)</code> would extract the geburtstag from a Person. From there, you could define functions such as:</p> <pre><code>getDay :: Geburtstag -> Int getDay (Gtg d _ _) = d </code></pre> <p>And then <code>getDay (geburtstag (getPerson myEintrag))</code>, or equivalently, <code>getDay . geburtstag . getPerson $ myEintrag</code> would get you the day from the Eintrag.</p>

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