haskell-lectures/VL1/content/VL1_ADT1.tex

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Of course we can also define our own data types in haskell. One very common type is the \emph{enumeration}. For example, we could define a data type for the Week:
\begin{haskellcode}
data WeekDay = Monday
| Tuesday
| Thursday
| Wednesday
| Friday
| Saturday
| Sunday
\end{haskellcode}
This declares the new data type \code{WeekDay} with 7 \emph{constructors}. That means \code{Monday}, \code{Tuesday} etc. are all values of the type \code{WeekDay}.
\pause
\\
We could now define a whole week, by creating a list:
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\begin{haskellcode}
week :: [WeekDay]
week = [Monday, Tuesday, Thursday, Wednesday
, Friday, Saturday, Sunday]
\end{haskellcode}