37 lines
1,007 B
Haskell
37 lines
1,007 B
Haskell
|
{- dotted versions, such as 1.0.1
|
||
|
|
-
|
||
|
|
- Copyright 2011-2014 Joey Hess <joey@kitenet.net>
|
||
|
|
-
|
||
|
|
- License: BSD-2-clause
|
||
|
|
-}
|
||
|
|
|
||
|
|
module Utility.DottedVersion where
|
||
|
|
|
||
|
|
import Common
|
||
|
|
|
||
|
|
data DottedVersion = DottedVersion String Integer
|
||
|
|
deriving (Eq)
|
||
|
|
|
||
|
|
instance Ord DottedVersion where
|
||
|
|
compare (DottedVersion _ x) (DottedVersion _ y) = compare x y
|
||
|
|
|
||
|
|
instance Show DottedVersion where
|
||
|
|
show (DottedVersion s _) = s
|
||
|
|
|
||
|
|
{- To compare dotted versions like 1.7.7 and 1.8, they are normalized to
|
||
|
|
- a somewhat arbitrary integer representation. -}
|
||
|
|
normalize :: String -> DottedVersion
|
||
|
|
normalize v = DottedVersion v $
|
||
|
|
sum $ mult 1 $ reverse $ extend precision $ take precision $
|
||
|
|
map readi $ split "." v
|
||
|
|
where
|
||
|
|
extend n l = l ++ replicate (n - length l) 0
|
||
|
|
mult _ [] = []
|
||
|
|
mult n (x:xs) = (n*x) : mult (n*10^width) xs
|
||
|
|
readi :: String -> Integer
|
||
|
|
readi s = case reads s of
|
||
|
|
((x,_):_) -> x
|
||
|
|
_ -> 0
|
||
|
|
precision = 10 -- number of segments of the version to compare
|
||
|
|
width = length "yyyymmddhhmmss" -- maximum width of a segment
|