Safe Haskell | None |
---|---|
Language | Haskell2010 |
Synopsis
- data ComponentRequestedSpec
- data ComponentDisabledReason
- defaultComponentRequestedSpec :: ComponentRequestedSpec
- componentNameRequested :: ComponentRequestedSpec -> ComponentName -> Bool
- componentEnabled :: ComponentRequestedSpec -> Component -> Bool
- componentDisabledReason :: ComponentRequestedSpec -> Component -> Maybe ComponentDisabledReason
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 Source #
Describes what components are enabled by user-interaction. See also this note in Distribution.Types.ComponentRequestedSpec.
Since: Cabal-2.0.0.2
Instances
data ComponentDisabledReason Source #
A reason explaining why a component is disabled.
Since: Cabal-2.0.0.2
defaultComponentRequestedSpec :: ComponentRequestedSpec Source #
The default set of enabled components. Historically tests and benchmarks are NOT enabled by default.
Since: Cabal-2.0.0.2
componentNameRequested :: ComponentRequestedSpec -> ComponentName -> Bool Source #
Is this component name enabled? See also this note in Distribution.Types.ComponentRequestedSpec.
Since: Cabal-2.0.0.2
componentEnabled :: ComponentRequestedSpec -> Component -> Bool Source #
Is this component enabled? See also this note in Distribution.Types.ComponentRequestedSpec.
Since: Cabal-2.0.0.2
componentDisabledReason :: ComponentRequestedSpec -> Component -> Maybe ComponentDisabledReason Source #
Is this component disabled, and if so, why?
Since: Cabal-2.0.0.2