{-# LANGUAGE Safe #-} {-# LANGUAGE DeriveGeneric #-} {-# LANGUAGE NoImplicitPrelude #-} ----------------------------------------------------------------------------- -- | -- Module : Data.Version -- Copyright : (c) The University of Glasgow 2004 -- License : BSD-style (see the file libraries/base/LICENSE) -- -- Maintainer : libraries@haskell.org -- Stability : experimental -- Portability : non-portable (local universal quantification in ReadP) -- -- A general library for representation and manipulation of versions. -- -- Versioning schemes are many and varied, so the version -- representation provided by this library is intended to be a -- compromise between complete generality, where almost no common -- functionality could reasonably be provided, and fixing a particular -- versioning scheme, which would probably be too restrictive. -- -- So the approach taken here is to provide a representation which -- subsumes many of the versioning schemes commonly in use, and we -- provide implementations of 'Eq', 'Ord' and conversion to\/from 'String' -- which will be appropriate for some applications, but not all. -- ----------------------------------------------------------------------------- module Data.Version ( -- * The @Version@ type Version(..), -- * A concrete representation of @Version@ showVersion, parseVersion, -- * Constructor function makeVersion ) where import Data.Functor ( Functor(..) ) import Control.Applicative ( Applicative(..) ) import Data.Bool ( (&&) ) import Data.Char ( isDigit, isAlphaNum ) import Data.Eq import Data.Int ( Int ) import Data.List ( map, sort, concat, concatMap, intersperse, (++) ) import Data.Ord import Data.String ( String ) import GHC.Generics import GHC.Read import GHC.Show import Text.ParserCombinators.ReadP import Text.Read ( read ) {- | A 'Version' represents the version of a software entity. An instance of 'Eq' is provided, which implements exact equality modulo reordering of the tags in the 'versionTags' field. An instance of 'Ord' is also provided, which gives lexicographic ordering on the 'versionBranch' fields (i.e. 2.1 > 2.0, 1.2.3 > 1.2.2, etc.). This is expected to be sufficient for many uses, but note that you may need to use a more specific ordering for your versioning scheme. For example, some versioning schemes may include pre-releases which have tags @\"pre1\"@, @\"pre2\"@, and so on, and these would need to be taken into account when determining ordering. In some cases, date ordering may be more appropriate, so the application would have to look for @date@ tags in the 'versionTags' field and compare those. The bottom line is, don't always assume that 'compare' and other 'Ord' operations are the right thing for every 'Version'. Similarly, concrete representations of versions may differ. One possible concrete representation is provided (see 'showVersion' and 'parseVersion'), but depending on the application a different concrete representation may be more appropriate. -} data Version = Version { Version -> [Int] versionBranch :: [Int], -- ^ The numeric branch for this version. This reflects the -- fact that most software versions are tree-structured; there -- is a main trunk which is tagged with versions at various -- points (1,2,3...), and the first branch off the trunk after -- version 3 is 3.1, the second branch off the trunk after -- version 3 is 3.2, and so on. The tree can be branched -- arbitrarily, just by adding more digits. -- -- We represent the branch as a list of 'Int', so -- version 3.2.1 becomes [3,2,1]. Lexicographic ordering -- (i.e. the default instance of 'Ord' for @[Int]@) gives -- the natural ordering of branches. Version -> [String] versionTags :: [String] -- really a bag -- ^ A version can be tagged with an arbitrary list of strings. -- The interpretation of the list of tags is entirely dependent -- on the entity that this version applies to. } deriving ( Read -- ^ @since 2.01 , Show -- ^ @since 2.01 , Generic -- ^ @since 4.9.0.0 ) {-# DEPRECATED versionTags "See GHC ticket #2496" #-} -- TODO. Remove all references to versionTags in GHC 8.0 release. -- | @since 2.01 instance Eq Version where Version v1 == :: Version -> Version -> Bool == Version v2 = Version -> [Int] versionBranch Version v1 [Int] -> [Int] -> Bool forall a. Eq a => a -> a -> Bool == Version -> [Int] versionBranch Version v2 Bool -> Bool -> Bool && [String] -> [String] forall a. Ord a => [a] -> [a] sort (Version -> [String] versionTags Version v1) [String] -> [String] -> Bool forall a. Eq a => a -> a -> Bool == [String] -> [String] forall a. Ord a => [a] -> [a] sort (Version -> [String] versionTags Version v2) -- tags may be in any order -- | @since 2.01 instance Ord Version where Version v1 compare :: Version -> Version -> Ordering `compare` Version v2 = Version -> [Int] versionBranch Version v1 [Int] -> [Int] -> Ordering forall a. Ord a => a -> a -> Ordering `compare` Version -> [Int] versionBranch Version v2 -- ----------------------------------------------------------------------------- -- A concrete representation of 'Version' -- | Provides one possible concrete representation for 'Version'. For -- a version with 'versionBranch' @= [1,2,3]@ and 'versionTags' -- @= [\"tag1\",\"tag2\"]@, the output will be @1.2.3-tag1-tag2@. -- showVersion :: Version -> String showVersion :: Version -> String showVersion (Version [Int] branch [String] tags) = [String] -> String forall (t :: * -> *) a. Foldable t => t [a] -> [a] concat (String -> [String] -> [String] forall a. a -> [a] -> [a] intersperse String "." ((Int -> String) -> [Int] -> [String] forall a b. (a -> b) -> [a] -> [b] map Int -> String forall a. Show a => a -> String show [Int] branch)) String -> ShowS forall a. [a] -> [a] -> [a] ++ ShowS -> [String] -> String forall (t :: * -> *) a b. Foldable t => (a -> [b]) -> t a -> [b] concatMap (Char '-'Char -> ShowS forall a. a -> [a] -> [a] :) [String] tags -- | A parser for versions in the format produced by 'showVersion'. -- parseVersion :: ReadP Version parseVersion :: ReadP Version parseVersion = do [Int] branch <- ReadP Int -> ReadP Char -> ReadP [Int] forall a sep. ReadP a -> ReadP sep -> ReadP [a] sepBy1 ((String -> Int) -> ReadP String -> ReadP Int forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b fmap String -> Int forall a. Read a => String -> a read ((Char -> Bool) -> ReadP String munch1 Char -> Bool isDigit)) (Char -> ReadP Char char Char '.') [String] tags <- ReadP String -> ReadP [String] forall a. ReadP a -> ReadP [a] many (Char -> ReadP Char char Char '-' ReadP Char -> ReadP String -> ReadP String forall (f :: * -> *) a b. Applicative f => f a -> f b -> f b *> (Char -> Bool) -> ReadP String munch1 Char -> Bool isAlphaNum) Version -> ReadP Version forall (f :: * -> *) a. Applicative f => a -> f a pure Version :: [Int] -> [String] -> Version Version{versionBranch :: [Int] versionBranch=[Int] branch, versionTags :: [String] versionTags=[String] tags} -- | Construct tag-less 'Version' -- -- @since 4.8.0.0 makeVersion :: [Int] -> Version makeVersion :: [Int] -> Version makeVersion [Int] b = [Int] -> [String] -> Version Version [Int] b []