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22 lines
347 B
Idris
22 lines
347 B
Idris
data Foo = A | B | C
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Eq Foo where
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A == A = True
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B == B = True
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C == C = True
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_ == _ = False
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interface Read a where
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readPrefix : String -> Maybe (a, String)
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read : String -> Maybe a
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read str = case readPrefix str of
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Just (a, "") => pure a
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Nothing => Nothing
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Read Foo where
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read "A" = A
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read "B" = B
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read "C" = C
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