24 lines
411 B
Text
24 lines
411 B
Text
data Maybe (a) where {
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Nothing : Maybe (a)
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Just : forall a. a -> Maybe (a)
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};
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fromJust : Maybe (a) -> a ;
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fromJust a =
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case a of {
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Just a => a
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};
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fromMaybe : a -> Maybe (a) -> a ;
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fromMaybe a b =
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case b of {
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Just a => a;
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Nothing => a
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};
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maybe : b -> (a -> b) -> Maybe (a) -> b;
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maybe b f ma =
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case ma of {
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Just a => f a;
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Nothing => b
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}
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