Created
May 13, 2024 14:47
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Compare lengths of finite and infinite lists
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| data Length = forall x. Length { unLength :: [x] } | |
| instance Eq Length where | |
| (==) (Length []) (Length []) = True | |
| (==) (Length (_:xs)) (Length (_:ys)) = Length xs == Length ys | |
| (==) _ _ = False | |
| instance Ord Length where | |
| compare (Length []) (Length []) = EQ | |
| compare (Length (_:_)) (Length []) = GT | |
| compare (Length []) (Length (_:_)) = LT | |
| compare (Length (_:xs)) (Length (_:ys)) = compare (Length xs) (Length ys) | |
| toLength :: Length -> Int | |
| toLength (Length xs) = length xs | |
| length' :: [x] -> Length | |
| length' = Length |
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