| Portability | portable | 
|---|---|
| Maintainer | cabal-devel@haskell.org | 
| Safe Haskell | Safe-Inferred | 
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".
- data  Version  = Version {- versionBranch :: [Int]
- versionTags :: [String]
 
- data VersionRange
- anyVersion :: VersionRange
- noVersion :: VersionRange
- thisVersion :: Version -> VersionRange
- notThisVersion :: Version -> VersionRange
- laterVersion :: Version -> VersionRange
- earlierVersion :: Version -> VersionRange
- orLaterVersion :: Version -> VersionRange
- orEarlierVersion :: Version -> VersionRange
- unionVersionRanges :: VersionRange -> VersionRange -> VersionRange
- intersectVersionRanges :: VersionRange -> VersionRange -> VersionRange
- withinVersion :: Version -> VersionRange
- betweenVersionsInclusive :: Version -> Version -> VersionRange
- withinRange :: Version -> VersionRange -> Bool
- isAnyVersion :: VersionRange -> Bool
- isNoVersion :: VersionRange -> Bool
- isSpecificVersion :: VersionRange -> Maybe Version
- simplifyVersionRange :: VersionRange -> VersionRange
- foldVersionRange :: a -> (Version -> a) -> (Version -> a) -> (Version -> a) -> (a -> a -> a) -> (a -> a -> a) -> VersionRange -> a
- foldVersionRange' :: a -> (Version -> a) -> (Version -> a) -> (Version -> a) -> (Version -> a) -> (Version -> a) -> (Version -> Version -> a) -> (a -> a -> a) -> (a -> a -> a) -> (a -> a) -> VersionRange -> a
- asVersionIntervals :: VersionRange -> [VersionInterval]
- type VersionInterval = (LowerBound, UpperBound)
- data LowerBound = LowerBound Version !Bound
- data UpperBound
- data Bound
- data VersionIntervals
- toVersionIntervals :: VersionRange -> VersionIntervals
- fromVersionIntervals :: VersionIntervals -> VersionRange
- withinIntervals :: Version -> VersionIntervals -> Bool
- versionIntervals :: VersionIntervals -> [VersionInterval]
- mkVersionIntervals :: [VersionInterval] -> Maybe VersionIntervals
- unionVersionIntervals :: VersionIntervals -> VersionIntervals -> VersionIntervals
- intersectVersionIntervals :: VersionIntervals -> VersionIntervals -> VersionIntervals
Package versions
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.
Constructors
| Version | |
| Fields 
 | |
Version ranges
data VersionRange
Constructors
| AnyVersion | Deprecated: Use  | 
| ThisVersion Version | Deprecated: use  | 
| LaterVersion Version | Deprecated: use  | 
| EarlierVersion Version | Deprecated: use  | 
| WildcardVersion Version | Deprecated: use  | 
| UnionVersionRanges VersionRange VersionRange | Deprecated: use  | 
| IntersectVersionRanges VersionRange VersionRange | Deprecated: use  | 
| VersionRangeParens VersionRange | 
Instances
Constructing
The version range -any. That is, a version range containing all
 versions.
withinRange v anyVersion = True
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 anyVersion = 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
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'
Arguments
| :: a | 
 | 
| -> (Version -> a) | "== v" | 
| -> (Version -> a) | "> v" | 
| -> (Version -> a) | "< v" | 
| -> (a -> a -> a) | 
 | 
| -> (a -> a -> a) | 
 | 
| -> VersionRange | |
| -> a | 
Fold over the basic syntactic structure of a VersionRange.
This provides a syntacic 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.
Arguments
| :: a | 
 | 
| -> (Version -> a) | "== v" | 
| -> (Version -> a) | "> v" | 
| -> (Version -> a) | "< v" | 
| -> (Version -> a) | ">= v" | 
| -> (Version -> a) | "<= v" | 
| -> (Version -> Version -> a) | 
 | 
| -> (a -> a -> a) | 
 | 
| -> (a -> a -> a) | 
 | 
| -> (a -> a) | 
 | 
| -> VersionRange | |
| -> a | 
An extended variant of foldVersionRange that also provides a view of
 in which the syntactic sugar ">= v", "<= v" and "== v.*" is presented
 explicitly rather than in terms of the other basic syntax.
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
type VersionInterval = (LowerBound, UpperBound)
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.
Instances
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 invervals may overlap or touch. If any of these conditions are not
 satisfied the function returns Nothing.