Struct FeatureGraph

pub struct FeatureGraph<'g> { /* private fields */ }

A derived graph representing every feature of every package.

Constructed through PackageGraph::feature_graph.

Implementations

impl<'g> FeatureGraph<'g>

pub fn build_warnings(&self) -> &'g [FeatureGraphWarning]

Returns any non-fatal warnings encountered while constructing the feature graph.

pub fn package_graph(&self) -> &'g PackageGraph

Returns the PackageGraph from which this feature graph was constructed.

pub fn feature_count(&self) -> usize

Returns the total number of (package ID, feature) combinations in this graph.

Includes the “base” feature for each package.

pub fn link_count(&self) -> usize

Returns the number of links in this graph.

pub fn contains(&self, feature_id: impl Into<FeatureId<'g>>) -> bool

Returns true if this feature graph contains the specified feature.

pub fn metadata( &self, feature_id: impl Into<FeatureId<'g>>, ) -> Result<FeatureMetadata<'g>, Error>

Returns metadata for the given feature ID, or None if the feature wasn’t found.

pub fn all_features_for( &self, package_id: &PackageId, ) -> Result<FeatureList<'g>, Error>

Returns all known features for a package.

Returns an error if the package ID was unknown.

pub fn is_default_feature<'a>( &self, feature_id: impl Into<FeatureId<'a>>, ) -> Result<bool, Error>

Returns true if this feature is included in a package’s build by default.

Returns an error if this feature ID is unknown.

Cycles

A cyclic dev-dependency may cause additional features to be turned on. This computation does not follow conditional links and will not return true for such additional features.

pub fn depends_on<'a>( &self, feature_a: impl Into<FeatureId<'a>>, feature_b: impl Into<FeatureId<'a>>, ) -> Result<bool, Error>

Returns true if feature_a depends (directly or indirectly) on feature_b.

In other words, this returns true if feature_b is a (possibly transitive) dependency of feature_a.

This also returns true if feature_a is the same as feature_b.

Note that this returns true if feature_a conditionally depends on feature_b.

pub fn directly_depends_on<'a>( &self, feature_a: impl Into<FeatureId<'a>>, feature_b: impl Into<FeatureId<'a>>, ) -> Result<bool, Error>

Returns true if feature_a directly depends on feature_b.

In other words, this returns true if feature_a is a direct dependency of feature_b.

This returns false if feature_a is the same as feature_b.

pub fn cycles(&self) -> Cycles<'g>

Returns information about dependency cycles.

For more information, see the documentation for Cycles.

impl<'g> FeatureGraph<'g>

Queries

The methods in this section create queries over subsets of this feature graph. Use the methods here to analyze transitive dependencies.

pub fn query_workspace( &self, filter: impl FeatureFilter<'g>, ) -> FeatureQuery<'g>

Creates a new query over the entire workspace.

query_workspace will select all workspace packages (subject to the provided filter) and their transitive dependencies.

pub fn query_directed<'a>( &self, feature_ids: impl IntoIterator<Item = impl Into<FeatureId<'a>>>, dep_direction: DependencyDirection, ) -> Result<FeatureQuery<'g>, Error>

Creates a new query that returns transitive dependencies of the given feature IDs in the specified direction.

Returns an error if any feature IDs are unknown.

pub fn query_forward<'a>( &self, feature_ids: impl IntoIterator<Item = impl Into<FeatureId<'a>>>, ) -> Result<FeatureQuery<'g>, Error>

Creates a new query that returns transitive dependencies of the given feature IDs.

Returns an error if any feature IDs are unknown.

pub fn query_reverse<'a>( &self, feature_ids: impl IntoIterator<Item = impl Into<FeatureId<'a>>>, ) -> Result<FeatureQuery<'g>, Error>

Creates a new query that returns transitive reverse dependencies of the given feature IDs.

Returns an error if any feature IDs are unknown.

impl<'g> FeatureGraph<'g>

pub fn resolve_all(&self) -> FeatureSet<'g>

Creates a new FeatureSet consisting of all members of this feature graph.

This will include features that aren’t depended on by any workspace packages.

In most situations, query_workspace().resolve() is preferred. Use resolve_all if you know you need parts of the graph that aren’t accessible from the workspace.

pub fn resolve_none(&self) -> FeatureSet<'g>

Creates a new, empty FeatureSet associated with this feature graph.

pub fn resolve_ids<'a>( &self, feature_ids: impl IntoIterator<Item = impl Into<FeatureId<'a>>>, ) -> Result<FeatureSet<'g>, Error>

Creates a new FeatureSet consisting of the specified feature IDs.

Returns an error if any feature IDs are unknown.

Trait Implementations

impl<'g> Clone for FeatureGraph<'g>

fn clone(&self) -> FeatureGraph<'g>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'g> Debug for FeatureGraph<'g>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'g> Copy for FeatureGraph<'g>