Distribution.Client.Dependency · cabal-install-3.12.1.0

The main package dependency resolver

4 declarations

datadata DepResolverParams

The set of parameters to the dependency resolver. These parameters are relatively low level but many kinds of high level policies can be implemented in terms of adjustments to the parameters.

valueresolveDependencies

:: Platform
-> CompilerInfo
-> PkgConfigDb
-> DepResolverParams
-> Progress String String SolverInstallPlan

#

Run the dependency solver.

Since this is potentially an expensive operation, the result is wrapped in a a Progress structure that can be unfolded to provide progress information, logging messages and the final result or an error.

datadata Progress step fail done

#

A type to represent the unfolding of an expensive long running calculation that may fail. We may get intermediate steps before the final result which may be used to indicate progress and/or logging messages.

Constructors

Step step (Progress step fail done)
Fail fail
Done done

Instances4Monad, Functor, Applicative, Alternative

Monad (Progress step fail)Defined in cabal-install-solver-3.12.1.0 · Distribution.Solver.Types.Progress
Functor (Progress step fail)Defined in cabal-install-solver-3.12.1.0 · Distribution.Solver.Types.Progress
Applicative (Progress step fail)Defined in cabal-install-solver-3.12.1.0 · Distribution.Solver.Types.Progress
Monoid fail => Alternative (Progress step fail)Defined in cabal-install-solver-3.12.1.0 · Distribution.Solver.Types.Progress

valuefoldProgress

:: step -> a -> a
-> fail -> a
-> done -> a
-> Progress step fail done
-> a

#

Consume a Progress calculation. Much like foldr for lists but with two base cases, one for a final result and one for failure.

Eg to convert into a simple Either result use:

foldProgress (flip const) Left Right

Alternate, simple resolver that does not do dependencies recursively

1 declaration

valueresolveWithoutDependencies

:: DepResolverParams
-> Either [ResolveNoDepsError] [UnresolvedSourcePackage]

#

A simplistic method of resolving a list of target package names to available packages.

Specifically, it does not consider package dependencies at all. Unlike resolveDependencies, no attempt is made to ensure that the selected packages have dependencies that are satisfiable or consistent with each other.

It is suitable for tasks such as selecting packages to download for user inspection. It is not suitable for selecting packages to install.

Note: if no installed package index is available, it is OK to pass mempty. It simply means preferences for installed packages will be ignored.

Constructing resolver policies

5 declarations

datadata PackageProperty

#

A package property is a logical predicate on packages.

Constructors

PackagePropertyVersion VersionRange
PackagePropertyInstalled
PackagePropertySource
PackagePropertyFlags FlagAssignment
PackagePropertyStanzas [OptionalStanza]

Instances6Eq, Show, Generic, Binary, Structured, Rep

Eq PackagePropertyDefined in cabal-install-solver-3.12.1.0 · Distribution.Solver.Types.PackageConstraint
Show PackagePropertyDefined in cabal-install-solver-3.12.1.0 · Distribution.Solver.Types.PackageConstraint
Generic PackagePropertyDefined in cabal-install-solver-3.12.1.0 · Distribution.Solver.Types.PackageConstraint
Binary PackagePropertyDefined in cabal-install-solver-3.12.1.0 · Distribution.Solver.Types.PackageConstraint
Structured PackagePropertyDefined in cabal-install-solver-3.12.1.0 · Distribution.Solver.Types.PackageConstraint
type Rep PackageProperty = D1 ('MetaData "PackageProperty" "Distribution.Solver.Types.PackageConstraint" "cabal-install-solver-3.12.1.0-582X8xReBAn365xYF5myIO" 'False) ((C1 ('MetaCons "PackagePropertyVersion" 'PrefixI 'False) (S1 ('MetaSel 'Nothing 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 VersionRange)) :+: C1 ('MetaCons "PackagePropertyInstalled" 'PrefixI 'False) U1) :+: (C1 ('MetaCons "PackagePropertySource" 'PrefixI 'False) U1 :+: (C1 ('MetaCons "PackagePropertyFlags" 'PrefixI 'False) (S1 ('MetaSel 'Nothing 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 FlagAssignment)) :+: C1 ('MetaCons "PackagePropertyStanzas" 'PrefixI 'False) (S1 ('MetaSel 'Nothing 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 [OptionalStanza])))))Defined in cabal-install-solver-3.12.1.0 · Distribution.Solver.Types.PackageConstraint

datadata PackageConstraint

#

A package constraint consists of a scope plus a property that must hold for all packages within that scope.

Constructors

PackageConstraint ConstraintScope PackageProperty

Instances2Eq, Show

Eq PackageConstraintDefined in cabal-install-solver-3.12.1.0 · Distribution.Solver.Types.PackageConstraint
Show PackageConstraintDefined in cabal-install-solver-3.12.1.0 · Distribution.Solver.Types.PackageConstraint

valuescopeToplevel :: PackageName -> ConstraintScope

#

Constructor for a common use case: the constraint applies to the package with the specified name when that package is a top-level dependency in the default namespace.

datadata PackagesPreferenceDefault

#

Global policy for all packages to say if we prefer package versions that are already installed locally or if we just prefer the latest available.

Constructors

PreferAllLatest
Always prefer the latest version irrespective of any existing installed version.
- This is the standard policy for upgrade.
PreferAllOldest
Always prefer the oldest version irrespective of any existing installed version or packages explicitly requested.
- This is enabled by --prefer-oldest.
PreferAllInstalled
Always prefer the installed versions over ones that would need to be installed. Secondarily, prefer latest versions (eg the latest installed version or if there are none then the latest source version).
PreferLatestForSelected
Prefer the latest version for packages that are explicitly requested but prefers the installed version for any other packages.
- This is the standard policy for install.

Instances1Show

Show PackagesPreferenceDefaultDefined in cabal-install-3.12.1.0 · Distribution.Client.Dependency.Types

datadata PackagePreference

#

A package selection preference for a particular package.

Preferences are soft constraints that the dependency resolver should try to respect where possible. It is not specified if preferences on some packages are more important than others.

Constructors

PackageVersionPreference PackageName VersionRange
A suggested constraint on the version number.
PackageInstalledPreference PackageName InstalledPreference
If we prefer versions of packages that are already installed.
PackageStanzasPreference PackageName [OptionalStanza]
If we would prefer to enable these optional stanzas (i.e. test suites and/or benchmarks)

Standard policy

valuebasicInstallPolicy

:: InstalledPackageIndex
-> SourcePackageDb
-> [PackageSpecifier UnresolvedSourcePackage]
-> DepResolverParams

#

A basic solver policy on which all others are built.

valuestandardInstallPolicy

:: InstalledPackageIndex
-> SourcePackageDb
-> [PackageSpecifier UnresolvedSourcePackage]
-> DepResolverParams

#

The policy used by all the standard commands, install, fetch, freeze etc (but not the v2-build and related commands).

It extends the basicInstallPolicy with a policy on setup deps.

datadata PackageSpecifier pkg

#

A fully or partially resolved reference to a package.

Constructors

NamedPackage PackageName [PackageProperty]
A partially specified reference to a package (either source or installed). It is specified by package name and optionally some required properties. Use a dependency resolver to pick a specific package satisfying these properties.
SpecificSourcePackage pkg
A fully specified source package.

Instances7Functor, Eq, Show, Generic, Binary, Structured, …

Functor PackageSpecifierDefined in cabal-install-3.12.1.0 · Distribution.Client.Types.PackageSpecifier
Eq pkg => Eq (PackageSpecifier pkg)Defined in cabal-install-3.12.1.0 · Distribution.Client.Types.PackageSpecifier
Show pkg => Show (PackageSpecifier pkg)Defined in cabal-install-3.12.1.0 · Distribution.Client.Types.PackageSpecifier
Generic (PackageSpecifier pkg)Defined in cabal-install-3.12.1.0 · Distribution.Client.Types.PackageSpecifier
Binary pkg => Binary (PackageSpecifier pkg)Defined in cabal-install-3.12.1.0 · Distribution.Client.Types.PackageSpecifier
Structured pkg => Structured (PackageSpecifier pkg)Defined in cabal-install-3.12.1.0 · Distribution.Client.Types.PackageSpecifier
type Rep (PackageSpecifier pkg) = D1 ('MetaData "PackageSpecifier" "Distribution.Client.Types.PackageSpecifier" "cabal-install-3.12.1.0-1D90DH9PPem9Tqn79I9vRN" 'False) (C1 ('MetaCons "NamedPackage" 'PrefixI 'False) (S1 ('MetaSel 'Nothing 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 PackageName) :*: S1 ('MetaSel 'Nothing 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 [PackageProperty])) :+: C1 ('MetaCons "SpecificSourcePackage" 'PrefixI 'False) (S1 ('MetaSel 'Nothing 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 pkg)))Defined in cabal-install-3.12.1.0 · Distribution.Client.Types.PackageSpecifier

Extra policy options

valueupgradeDependencies :: DepResolverParams -> DepResolverParams

#

valuereinstallTargets :: DepResolverParams -> DepResolverParams

#

Policy utils

valueaddConstraints

#

valueaddPreferences

:: [PackagePreference]
-> DepResolverParams
-> DepResolverParams

#

valuesetPreferenceDefault

#

valuesetReorderGoals :: ReorderGoals -> DepResolverParams -> DepResolverParams

#

valuesetCountConflicts

:: CountConflicts
-> DepResolverParams
-> DepResolverParams

#

valuesetFineGrainedConflicts

:: FineGrainedConflicts
-> DepResolverParams
-> DepResolverParams

#

valuesetMinimizeConflictSet

:: MinimizeConflictSet
-> DepResolverParams
-> DepResolverParams

#

valuesetIndependentGoals

:: IndependentGoals
-> DepResolverParams
-> DepResolverParams

#

valuesetAvoidReinstalls

:: AvoidReinstalls
-> DepResolverParams
-> DepResolverParams

#

valuesetShadowPkgs :: ShadowPkgs -> DepResolverParams -> DepResolverParams

#

valuesetStrongFlags :: StrongFlags -> DepResolverParams -> DepResolverParams

#

valuesetAllowBootLibInstalls

:: AllowBootLibInstalls
-> DepResolverParams
-> DepResolverParams

#

valuesetOnlyConstrained

:: OnlyConstrained
-> DepResolverParams
-> DepResolverParams

#

valuesetMaxBackjumps :: Maybe Int -> DepResolverParams -> DepResolverParams

#

valuesetEnableBackjumping

:: EnableBackjumping
-> DepResolverParams
-> DepResolverParams

#

valuesetSolveExecutables

:: SolveExecutables
-> DepResolverParams
-> DepResolverParams

#

valuesetGoalOrder

:: Maybe (Variable QPN -> Variable QPN -> Ordering)
-> DepResolverParams
-> DepResolverParams

#

valuesetSolverVerbosity :: Verbosity -> DepResolverParams -> DepResolverParams

#

valueremoveLowerBounds :: AllowOlder -> DepResolverParams -> DepResolverParams

#

Dual of removeUpperBounds

valueremoveUpperBounds :: AllowNewer -> DepResolverParams -> DepResolverParams

#

Remove upper bounds in dependencies using the policy specified by the AllowNewer argument (allsomenone).

Note: It's important to apply removeUpperBounds after addSourcePackages. Otherwise, the packages inserted by addSourcePackages won't have upper bounds in dependencies relaxed.

valueaddDefaultSetupDependencies

:: UnresolvedSourcePackage -> Maybe [Dependency]
-> DepResolverParams
-> DepResolverParams

#

Supply defaults for packages without explicit Setup dependencies

Note: It's important to apply addDefaultSetupDepends after addSourcePackages. Otherwise, the packages inserted by addSourcePackages won't have upper bounds in dependencies relaxed.

valueaddSetupCabalMinVersionConstraint

:: Version
-> DepResolverParams
-> DepResolverParams

#

If a package has a custom setup then we need to add a setup-depends on Cabal.

valueaddSetupCabalMaxVersionConstraint

:: Version
-> DepResolverParams
-> DepResolverParams

#

Variant of addSetupCabalMinVersionConstraint which sets an upper bound on setup.Cabal labeled with ConstraintSetupCabalMaxVersion.