20 regels
733 B
TeX
20 regels
733 B
TeX
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:
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\begin{haskellcode}
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data WeekDay = Monday
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| Tuesday
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| Thursday
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| Wednesday
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| Friday
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| Saturday
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| Sunday
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\end{haskellcode}
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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}.
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\pause
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\\
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We could now define a whole week, by creating a list:
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\pause
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\begin{haskellcode}
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week :: [WeekDay]
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week = [Monday, Tuesday, Thursday, Wednesday
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, Friday, Saturday, Sunday]
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\end{haskellcode} |