21 lines
450 B
Haskell
21 lines
450 B
Haskell
{- git-annex UUID type
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-
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- Copyright 2011 Joey Hess <joey@kitenet.net>
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-
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- Licensed under the GNU GPL version 3 or higher.
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-}
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module Types.UUID where
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-- A UUID is either an arbitrary opaque string, or UUID info may be missing.
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data UUID = NoUUID | UUID String
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deriving (Eq, Ord)
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instance Show UUID where
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show (UUID u) = u
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show NoUUID = ""
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instance Read UUID where
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readsPrec _ s
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| null s = [(NoUUID, "")]
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| otherwise = [(UUID s, "")]
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