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https://github.com/idris-lang/Idris2.git
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a972778eab
They don't all pass yet, for minor reasons. Coming shortly... Unfortunately the startup overhead for chez is really noticeable here!
35 lines
760 B
Idris
35 lines
760 B
Idris
data Fin : Nat -> Type where
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FZ : Fin (S k)
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FS : Fin k -> Fin (S k)
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interface Finite t where
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card : Nat
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to : t -> Fin card
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from : Fin card -> t
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toFrom : (k : Fin card) -> to (from k) = k
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fromTo : (x : t) -> from (to x) = x
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-- Checking dependent methods work, and that having names from the
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-- methods shadowed in the interface head doesn't cause any issues
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implementation Finite (Fin k) where
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card = ?ncard
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to = ?lala
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from = ?lula
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toFrom = ?foo
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fromTo = ?bar
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implementation Finite (Fin n) where
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card = ?ncard1
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to = ?lala1
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from = ?lula1
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toFrom = ?foo1
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fromTo = ?bar1
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implementation Finite (Fin t) where
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card = ?ncard2
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to = ?lala2
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from = ?lula2
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toFrom = ?foo2
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fromTo = ?bar2
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