Safe Haskell	None
Language	Haskell2010

Distribution.Types.ComponentRequestedSpec

Documentation

Note: Buildable versus requested versus enabled components

What's the difference between a buildable component (ala componentBuildable), a requested component (ala componentNameRequested), and an enabled component (ala componentEnabled)?

A component is buildable if, after resolving flags and conditionals, there is no buildable: False property in it. This is a static property that arises from the Cabal file and the package description flattening; once we have a PackageDescription buildability is known.

A component is requested if a user specified, via a the flags and arguments passed to configure, that it should be built. E.g., --enable-tests or --enable-benchmarks request all tests and benchmarks, if they are provided. What is requested can be read off directly from ComponentRequestedSpec. A requested component is not always buildable; e.g., a user may --enable-tests but one of the test suites may have buildable: False.

A component is enabled if it is BOTH buildable and requested. Once we have a LocalBuildInfo, whether or not a component is enabled is known.

Generally speaking, most Cabal API code cares if a component is enabled. (For example, if you want to run a preprocessor on each component prior to building them, you want to run this on each enabled component.)

Note that post-configuration, you will generally not see a non-buildable Component. This is because flattenPD will drop any such components from PackageDescription. See #3858 for an example where this causes problems.

data ComponentRequestedSpec #

Describes what components are enabled by user-interaction. See also this note in Distribution.Types.ComponentRequestedSpec.

Since: 2.0.0.2

Constructors

ComponentRequestedSpec
Fields testsRequested :: Bool benchmarksRequested :: Bool
OneComponentRequestedSpec ComponentName

Instances

Eq ComponentRequestedSpec #
Methods (==) :: ComponentRequestedSpec -> ComponentRequestedSpec -> Bool # (/=) :: ComponentRequestedSpec -> ComponentRequestedSpec -> Bool #
Read ComponentRequestedSpec #
Methods readsPrec :: Int -> ReadS ComponentRequestedSpec # readList :: ReadS [ComponentRequestedSpec] # readPrec :: ReadPrec ComponentRequestedSpec # readListPrec :: ReadPrec [ComponentRequestedSpec] #
Show ComponentRequestedSpec #
Methods showsPrec :: Int -> ComponentRequestedSpec -> ShowS # show :: ComponentRequestedSpec -> String # showList :: [ComponentRequestedSpec] -> ShowS #
Generic ComponentRequestedSpec #
Associated Types type Rep ComponentRequestedSpec :: * -> * # Methods from :: ComponentRequestedSpec -> Rep ComponentRequestedSpec x # to :: Rep ComponentRequestedSpec x -> ComponentRequestedSpec #
Binary ComponentRequestedSpec #
Methods put :: ComponentRequestedSpec -> Put # get :: Get ComponentRequestedSpec # putList :: [ComponentRequestedSpec] -> Put #
type Rep ComponentRequestedSpec #
type Rep ComponentRequestedSpec = D1 * (MetaData "ComponentRequestedSpec" "Distribution.Types.ComponentRequestedSpec" "Cabal-2.0.1.0-Jra8tLewAwA6OcEyyf1WGK" False) ((:+:) * (C1 * (MetaCons "ComponentRequestedSpec" PrefixI True) ((::) (S1 * (MetaSel (Just Symbol "testsRequested") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * Bool)) (S1 * (MetaSel (Just Symbol "benchmarksRequested") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * Bool)))) (C1 * (MetaCons "OneComponentRequestedSpec" PrefixI False) (S1 * (MetaSel (Nothing Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * ComponentName))))

data ComponentDisabledReason #

A reason explaining why a component is disabled.

Since: 2.0.0.2

Constructors

DisabledComponent
DisabledAllTests
DisabledAllBenchmarks
DisabledAllButOne String

defaultComponentRequestedSpec :: ComponentRequestedSpec #

The default set of enabled components. Historically tests and benchmarks are NOT enabled by default.

Since: 2.0.0.2

componentNameRequested :: ComponentRequestedSpec -> ComponentName -> Bool #

Is this component name enabled? See also this note in Distribution.Types.ComponentRequestedSpec.

Since: 2.0.0.2

componentEnabled :: ComponentRequestedSpec -> Component -> Bool #

Is this component enabled? See also this note in Distribution.Types.ComponentRequestedSpec.

Since: 2.0.0.2

componentDisabledReason :: ComponentRequestedSpec -> Component -> Maybe ComponentDisabledReason #

Is this component disabled, and if so, why?

Since: 2.0.0.2