Portability	portable
Maintainer	cabal-devel@haskell.org

Distribution.Package

Contents

Package ids
Installed package identifiers
Package source dependencies
Package classes

Description

Defines a package identifier along with a parser and pretty printer for it. PackageIdentifiers consist of a name and an exact version. It also defines a Dependency data type. A dependency is a package name and a version range, like "foo >= 1.2 && < 2".

Synopsis

Package ids

newtype PackageName Source

Constructors

PackageName String

Instances

Eq PackageName
Ord PackageName
Read PackageName
Show PackageName
Text PackageName

data PackageIdentifier Source

The name and version of a package.

Constructors

PackageIdentifier
Fields pkgName :: PackageName The name of this package, eg. foo pkgVersion :: Version the version of this package, eg 1.2

Instances

Eq PackageIdentifier
Ord PackageIdentifier
Read PackageIdentifier
Show PackageIdentifier
Text PackageIdentifier
Package PackageIdentifier

type PackageId = PackageIdentifier Source

Type alias so we can use the shorter name PackageId.

Installed package identifiers

newtype InstalledPackageId Source

An InstalledPackageId uniquely identifies an instance of an installed package. There can be at most one package with a given InstalledPackageId in a package database, or overlay of databases.

Constructors

InstalledPackageId String

Instances

Eq InstalledPackageId
Ord InstalledPackageId
Read InstalledPackageId
Show InstalledPackageId
Text InstalledPackageId

Package source dependencies

data Dependency Source

Describes a dependency on a source package (API)

Constructors

Dependency PackageName VersionRange

Instances

Eq Dependency
Read Dependency
Show Dependency
Text Dependency

thisPackageVersion :: PackageIdentifier -> Dependency Source

notThisPackageVersion :: PackageIdentifier -> Dependency Source

simplifyDependency :: Dependency -> Dependency Source

Simplify the VersionRange expression in a Dependency. See simplifyVersionRange.

Package classes

class Package pkg whereSource

Class of things that have a PackageIdentifier

Types in this class are all notions of a package. This allows us to have different types for the different phases that packages go though, from simple name/id, package description, configured or installed packages.

Not all kinds of packages can be uniquely identified by a PackageIdentifier. In particular, installed packages cannot, there may be many installed instances of the same source package.

Methods

packageId :: pkg -> PackageIdentifier Source

Instances

Package PackageIdentifier
Package GenericPackageDescription
Package PackageDescription
Package (InstalledPackageInfo_ str)

packageName :: Package pkg => pkg -> PackageName Source

packageVersion :: Package pkg => pkg -> Version Source

class Package pkg => PackageFixedDeps pkg whereSource

Subclass of packages that have specific versioned dependencies.

So for example a not-yet-configured package has dependencies on version ranges, not specific versions. A configured or an already installed package depends on exact versions. Some operations or data structures (like dependency graphs) only make sense on this subclass of package types.

Methods

depends :: pkg -> [PackageIdentifier]Source