git-annex/Types/UUID.hs

{- git-annex UUID type
 -
 - Copyright 2011 Joey Hess <joey@kitenet.net>
 -
 - Licensed under the GNU GPL version 3 or higher.
 -}

module Types.UUID where

-- A UUID is either an arbitrary opaque string, or UUID info may be missing.
data UUID = NoUUID | UUID String
	deriving (Eq, Ord, Show)

fromUUID :: UUID -> String
fromUUID (UUID u) = u
fromUUID NoUUID = ""

toUUID :: String -> UUID
toUUID [] = NoUUID
toUUID s = UUID s
better types allowed breaking module dep loop 2011-06-01 23:10:38 +00:00			`{- git-annex UUID type`
			`-`
			`- Copyright 2011 Joey Hess <joey@kitenet.net>`
			`-`
			`- Licensed under the GNU GPL version 3 or higher.`
			`-}`

rename modules for data types into Types/ directory 2011-06-02 01:56:04 +00:00			`module Types.UUID where`
better types allowed breaking module dep loop 2011-06-01 23:10:38 +00:00
add a UUID type Should have done this a long time ago. 2011-11-07 18:46:01 +00:00			`-- A UUID is either an arbitrary opaque string, or UUID info may be missing.`
			`data UUID = NoUUID \| UUID String`
clean up read/show abuse Avoid ever using read to parse a non-haskell formatted input string. show :: Key is arguably still show abuse, but displaying Keys as filenames is just too useful to give up. 2011-11-08 03:21:22 +00:00			`deriving (Eq, Ord, Show)`
add a UUID type Should have done this a long time ago. 2011-11-07 18:46:01 +00:00
clean up read/show abuse Avoid ever using read to parse a non-haskell formatted input string. show :: Key is arguably still show abuse, but displaying Keys as filenames is just too useful to give up. 2011-11-08 03:21:22 +00:00			`fromUUID :: UUID -> String`
			`fromUUID (UUID u) = u`
			`fromUUID NoUUID = ""`
add a UUID type Should have done this a long time ago. 2011-11-07 18:46:01 +00:00
clean up read/show abuse Avoid ever using read to parse a non-haskell formatted input string. show :: Key is arguably still show abuse, but displaying Keys as filenames is just too useful to give up. 2011-11-08 03:21:22 +00:00			`toUUID :: String -> UUID`
			`toUUID [] = NoUUID`
			`toUUID s = UUID s`