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Add pattern matching on MaybeInt

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Julian Ospald 2015-04-16 01:31:42 +02:00
parent 81170661bc
commit 40fb30148f
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1 changed files with 12 additions and 0 deletions
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VL1.tex
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@ -520,6 +520,18 @@ calcSomething x
\end{lstlisting} \end{lstlisting}
\end{frame} \end{frame}
\begin{frame}[fragile]
\frametitle{Algebraic Data Types (ctn.)}
And pattern match on it as well:
\setHaskellCodeStyle
\begin{lstlisting}
addIntToList :: MaybeInt -> [Int]
addIntToList (NoError x) = [x]
addIntToList (Error str) = []
\end{lstlisting}
So if we got an error, we just return an empty list, otherwise we return a list with the \code{Int} as its only element.
\end{frame}
\begin{frame}[fragile] \begin{frame}[fragile]
\frametitle{Algebraic Data Types (ctn.)} \frametitle{Algebraic Data Types (ctn.)}
Let's define something more complex. How about a tree? Let's define something more complex. How about a tree?