Distribution.Package

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".

Package ids

newtype PackageName

Constructors

PackageName String

Instances

Eq PackageName

Ord PackageName

Read PackageName

Show PackageName

Text PackageName

data PackageIdentifier

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

Type alias so we can use the shorter name PackageId.

Installed package identifiers

newtype InstalledPackageId

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

Describes a dependency on a source package (API)

Constructors

Dependency PackageName VersionRange

Instances

Eq Dependency

Read Dependency

Show Dependency

Text Dependency

thisPackageVersion :: PackageIdentifier -> Dependency

notThisPackageVersion :: PackageIdentifier -> Dependency

simplifyDependency :: Dependency -> Dependency

Simplify the VersionRange expression in a Dependency. See simplifyVersionRange.

Package classes

class Package pkg where

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

Instances

Package PackageIdentifier

Package GenericPackageDescription

Package PackageDescription

Package (InstalledPackageInfo_ str)

packageName :: Package pkg => pkg -> PackageName

packageVersion :: Package pkg => pkg -> Version

class Package pkg => PackageFixedDeps pkg where

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]