Cabal-1.24.0.0: A framework for packaging Haskell software

CopyrightIsaac Jones, Simon Marlow 2003-2004 Duncan Coutts 2008
LicenseBSD3
Maintainercabal-devel@haskell.org
Portabilityportable
Safe HaskellSafe
LanguageHaskell98

Distribution.Version

Contents

Description

Exports the Version type along with a parser and pretty printer. A version is something like "1.3.3". It also defines the VersionRange data types. Version ranges are like ">= 1.2 && < 2".

Synopsis

Package versions

data Version :: *

Constructors

Version 

Fields

versionBranch :: [Int]
 
versionTags :: [String]
 

Instances

IsList Version 
Eq Version 
Data Version 
Ord Version 
Read Version 
Show Version 
NFData Version 
Text Version 
type Item Version = Int 

Version ranges

Constructing

anyVersion :: VersionRange

The version range -any. That is, a version range containing all versions.

withinRange v anyVersion = True

noVersion :: VersionRange

The empty version range, that is a version range containing no versions.

This can be constructed using any unsatisfiable version range expression, for example > 1 && < 1.

withinRange v noVersion = False

thisVersion :: Version -> VersionRange

The version range == v

withinRange v' (thisVersion v) = v' == v

notThisVersion :: Version -> VersionRange

The version range || v

withinRange v' (notThisVersion v) = v' /= v

laterVersion :: Version -> VersionRange

The version range > v

withinRange v' (laterVersion v) = v' > v

earlierVersion :: Version -> VersionRange

The version range < v

withinRange v' (earlierVersion v) = v' < v

orLaterVersion :: Version -> VersionRange

The version range >= v

withinRange v' (orLaterVersion v) = v' >= v

orEarlierVersion :: Version -> VersionRange

The version range <= v

withinRange v' (orEarlierVersion v) = v' <= v

unionVersionRanges :: VersionRange -> VersionRange -> VersionRange

The version range vr1 || vr2

  withinRange v' (unionVersionRanges vr1 vr2)
= withinRange v' vr1 || withinRange v' vr2

intersectVersionRanges :: VersionRange -> VersionRange -> VersionRange

The version range vr1 && vr2

  withinRange v' (intersectVersionRanges vr1 vr2)
= withinRange v' vr1 && withinRange v' vr2

invertVersionRange :: VersionRange -> VersionRange

The inverse of a version range

  withinRange v' (invertVersionRange vr)
= not (withinRange v' vr)

withinVersion :: Version -> VersionRange

The version range == v.*.

For example, for version 1.2, the version range == 1.2.* is the same as >= 1.2 && < 1.3

withinRange v' (laterVersion v) = v' >= v && v' < upper v
  where
    upper (Version lower t) = Version (init lower ++ [last lower + 1]) t

betweenVersionsInclusive :: Version -> Version -> VersionRange

Deprecated: In practice this is not very useful because we normally use inclusive lower bounds and exclusive upper bounds

The version range >= v1 && <= v2.

In practice this is not very useful because we normally use inclusive lower bounds and exclusive upper bounds.

withinRange v' (laterVersion v) = v' > v

Inspection

withinRange :: Version -> VersionRange -> Bool

Does this version fall within the given range?

This is the evaluation function for the VersionRange type.

isAnyVersion :: VersionRange -> Bool

Does this VersionRange place any restriction on the Version or is it in fact equivalent to AnyVersion.

Note this is a semantic check, not simply a syntactic check. So for example the following is True (for all v).

isAnyVersion (EarlierVersion v `UnionVersionRanges` orLaterVersion v)

isNoVersion :: VersionRange -> Bool

This is the converse of isAnyVersion. It check if the version range is empty, if there is no possible version that satisfies the version range.

For example this is True (for all v):

isNoVersion (EarlierVersion v `IntersectVersionRanges` LaterVersion v)

isSpecificVersion :: VersionRange -> Maybe Version

Is this version range in fact just a specific version?

For example the version range ">= 3 && <= 3" contains only the version 3.

simplifyVersionRange :: VersionRange -> VersionRange

Simplify a VersionRange expression. For non-empty version ranges this produces a canonical form. Empty or inconsistent version ranges are left as-is because that provides more information.

If you need a canonical form use fromVersionIntervals . toVersionIntervals

It satisfies the following properties:

withinRange v (simplifyVersionRange r) = withinRange v r
    withinRange v r = withinRange v r'
==> simplifyVersionRange r = simplifyVersionRange r'
 || isNoVersion r
 || isNoVersion r'

foldVersionRange

Arguments

:: a

"-any" version

-> (Version -> a)
"== v"
-> (Version -> a)
"> v"
-> (Version -> a)
"< v"
-> (a -> a -> a)

"_ || _" union

-> (a -> a -> a)

"_ && _" intersection

-> VersionRange 
-> a 

Fold over the basic syntactic structure of a VersionRange.

This provides a syntactic view of the expression defining the version range. The syntactic sugar ">= v", "<= v" and "== v.*" is presented in terms of the other basic syntax.

For a semantic view use asVersionIntervals.

foldVersionRange'

Arguments

:: a

"-any" version

-> (Version -> a)
"== v"
-> (Version -> a)
"> v"
-> (Version -> a)
"< v"
-> (Version -> a)
">= v"
-> (Version -> a)
"<= v"
-> (Version -> Version -> a)

"== v.*" wildcard. The function is passed the inclusive lower bound and the exclusive upper bounds of the range defined by the wildcard.

-> (a -> a -> a)

"_ || _" union

-> (a -> a -> a)

"_ && _" intersection

-> (a -> a)

"(_)" parentheses

-> VersionRange 
-> a 

An extended variant of foldVersionRange that also provides a view of the expression in which the syntactic sugar ">= v", "<= v" and "== v.*" is presented explicitly rather than in terms of the other basic syntax.

hasUpperBound :: VersionRange -> Bool

Does the version range have an upper bound?

Since: 1.24.0.0

hasLowerBound :: VersionRange -> Bool

Does the version range have an explicit lower bound?

Note: this function only considers the user-specified lower bounds, but not the implicit >=0 lower bound.

Since: 1.24.0.0

Modification

removeUpperBound :: VersionRange -> VersionRange

Given a version range, remove the highest upper bound. Example: (>= 1 && < 3) || (>= 4 && < 5) is converted to (>= 1 && || (= 4).

Version intervals view

asVersionIntervals :: VersionRange -> [VersionInterval]

View a VersionRange as a union of intervals.

This provides a canonical view of the semantics of a VersionRange as opposed to the syntax of the expression used to define it. For the syntactic view use foldVersionRange.

Each interval is non-empty. The sequence is in increasing order and no intervals overlap or touch. Therefore only the first and last can be unbounded. The sequence can be empty if the range is empty (e.g. a range expression like && 2).

Other checks are trivial to implement using this view. For example:

isNoVersion vr | [] <- asVersionIntervals vr = True
               | otherwise                   = False
isSpecificVersion vr
   | [(LowerBound v  InclusiveBound
      ,UpperBound v' InclusiveBound)] <- asVersionIntervals vr
   , v == v'   = Just v
   | otherwise = Nothing

data LowerBound

Constructors

LowerBound Version !Bound 

Instances

data UpperBound

Instances

data Bound

Instances

Eq Bound 
Show Bound 

VersionIntervals abstract type

The VersionIntervals type and the accompanying functions are exposed primarily for completeness and testing purposes. In practice asVersionIntervals is the main function to use to view a VersionRange as a bunch of VersionIntervals.

data VersionIntervals

A complementary representation of a VersionRange. Instead of a boolean version predicate it uses an increasing sequence of non-overlapping, non-empty intervals.

The key point is that this representation gives a canonical representation for the semantics of VersionRanges. This makes it easier to check things like whether a version range is empty, covers all versions, or requires a certain minimum or maximum version. It also makes it easy to check equality or containment. It also makes it easier to identify 'simple' version predicates for translation into foreign packaging systems that do not support complex version range expressions.

toVersionIntervals :: VersionRange -> VersionIntervals

Convert a VersionRange to a sequence of version intervals.

fromVersionIntervals :: VersionIntervals -> VersionRange

Convert a VersionIntervals value back into a VersionRange expression representing the version intervals.

withinIntervals :: Version -> VersionIntervals -> Bool

Test if a version falls within the version intervals.

It exists mostly for completeness and testing. It satisfies the following properties:

withinIntervals v (toVersionIntervals vr) = withinRange v vr
withinIntervals v ivs = withinRange v (fromVersionIntervals ivs)

versionIntervals :: VersionIntervals -> [VersionInterval]

Inspect the list of version intervals.

mkVersionIntervals :: [VersionInterval] -> Maybe VersionIntervals

Directly construct a VersionIntervals from a list of intervals.

Each interval must be non-empty. The sequence must be in increasing order and no intervals may overlap or touch. If any of these conditions are not satisfied the function returns Nothing.