Struct FeatureSet

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

A set of resolved feature IDs in a feature graph.

Created by FeatureQuery::resolve, the FeatureGraph::resolve_ methods, or from PackageSet::to_feature_set.

Implementations

impl<'g> FeatureSet<'g>

pub fn graph(&self) -> &FeatureGraph<'g>

Returns the FeatureGraph that this feature set was computed against.

pub fn len(&self) -> usize

Returns the number of feature IDs in this set.

pub fn is_empty(&self) -> bool

Returns true if no feature IDs were resolved in this set.

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

Returns true if this set contains the given feature ID.

Returns an error if this feature ID was unknown.

pub fn contains_package(&self, package_id: &PackageId) -> Result<bool, Error>

Returns true if this set contains this package.

Returns an error if this package ID was unknown.

pub fn to_feature_query( &self, direction: DependencyDirection, ) -> FeatureQuery<'g>

Creates a new FeatureQuery from this set in the specified direction.

This is equivalent to constructing a query from all the feature IDs in this set.

pub fn union(&self, other: &Self) -> Self

Returns a FeatureSet that contains all packages present in at least one of self and other.

Panics

Panics if the package graphs associated with self and other don’t match.

pub fn intersection(&self, other: &Self) -> Self

Returns a FeatureSet that contains all packages present in both self and other.

Panics

Panics if the package graphs associated with self and other don’t match.

pub fn difference(&self, other: &Self) -> Self

Returns a FeatureSet that contains all packages present in self but not other.

Panics

Panics if the package graphs associated with self and other don’t match.

pub fn symmetric_difference(&self, other: &Self) -> Self

Returns a FeatureSet that contains all packages present in exactly one of self and other.

Panics

Panics if the package graphs associated with self and other don’t match.

pub fn filter( &self, direction: DependencyDirection, callback: impl FnMut(FeatureMetadata<'g>) -> bool, ) -> Self

Returns a PackageSet on which a filter has been applied.

Filters out all values for which the callback returns false.

Cycles

For packages within a dependency cycle, the callback will be called in non-dev order. When the direction is forward, if package Foo has a dependency on Bar, and Bar has a cyclic dev-dependency on Foo, then Foo is returned before Bar.

pub fn partition( &self, direction: DependencyDirection, callback: impl FnMut(FeatureMetadata<'g>) -> bool, ) -> (Self, Self)

Partitions this PackageSet into two.

The first PackageSet contains packages for which the callback returned true, and the second one contains packages for which the callback returned false.

Cycles

For packages within a dependency cycle, the callback will be called in non-dev order. When the direction is forward, if package Foo has a dependency on Bar, and Bar has a cyclic dev-dependency on Foo, then Foo is returned before Bar.

pub fn filter_partition( &self, direction: DependencyDirection, callback: impl FnMut(FeatureMetadata<'g>) -> Option<bool>, ) -> (Self, Self)

Performs filtering and partitioning at the same time.

The first PackageSet contains packages for which the callback returned Some(true), and the second one contains packages for which the callback returned Some(false). Packages for which the callback returned None are dropped.

Cycles

For packages within a dependency cycle, the callback will be called in non-dev order. When the direction is forward, if package Foo has a dependency on Bar, and Bar has a cyclic dev-dependency on Foo, then Foo is returned before Bar.

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

Returns a list of features present for this package, or None if this package is not present in the feature set.

Returns an error if the package ID was unknown.

pub fn to_package_set(&self) -> PackageSet<'g>

Converts this FeatureSet into a PackageSet containing all packages with any selected features (including the “base” feature).

pub fn into_cargo_set( self, opts: &CargoOptions<'_>, ) -> Result<CargoSet<'g>, Error>

Converts this feature set into a Cargo set, simulating a Cargo build for it.

The feature set is expected to be entirely within the workspace. Its behavior outside the workspace isn’t defined and may be surprising.

Returns an error if the CargoOptions weren’t valid in some way (for example if an omitted package ID wasn’t known to this graph.)

pub fn feature_ids<'a>( &'a self, direction: DependencyDirection, ) -> impl Iterator<Item = FeatureId<'g>> + ExactSizeIterator + 'a

Iterates over feature IDs, in topological order in the direction specified.

Cycles

The features within a dependency cycle will be returned in non-dev order. When the direction is forward, if feature Foo has a dependency on Bar, and Bar has a cyclic dev-dependency on Foo, then Foo is returned before Bar.

pub fn features<'a>( &'a self, direction: DependencyDirection, ) -> impl Iterator<Item = FeatureMetadata<'g>> + ExactSizeIterator + 'a

Iterates over feature metadatas, in topological order in the direction specified.

Cycles

The features within a dependency cycle will be returned in non-dev order. When the direction is forward, if feature Foo has a dependency on Bar, and Bar has a cyclic dev-dependency on Foo, then Foo is returned before Bar.

pub fn packages_with_features<'a>( &'a self, direction: DependencyDirection, ) -> impl Iterator<Item = FeatureList<'g>> + 'a

Iterates over package metadatas and their corresponding features, in topological order in the direction specified.

Cycles

The packages within a dependency cycle will be returned in non-dev order. When the direction is forward, if package Foo has a dependency on Bar, and Bar has a cyclic dev-dependency on Foo, then Foo is returned before Bar.

pub fn root_ids<'a>( &'a self, direction: DependencyDirection, ) -> impl Iterator<Item = FeatureId<'g>> + ExactSizeIterator + 'a

Returns the set of “root feature” IDs in the specified direction.

• If direction is Forward, return the set of feature IDs that do not have any dependencies within the selected graph.
• If direction is Reverse, return the set of feature IDs that do not have any dependents within the selected graph.

Cycles

If a root consists of a dependency cycle, all the packages in it will be returned in non-dev order (when the direction is forward).

pub fn root_features<'a>( &'a self, direction: DependencyDirection, ) -> impl Iterator<Item = FeatureMetadata<'g>> + 'a

Returns the set of “root feature” metadatas in the specified direction.

• If direction is Forward, return the set of metadatas that do not have any dependencies within the selected graph.
• If direction is Reverse, return the set of metadatas that do not have any dependents within the selected graph.

Cycles

If a root consists of a dependency cycle, all the packages in it will be returned in non-dev order (when the direction is forward).

pub fn conditional_links<'a>( &'a self, direction: DependencyDirection, ) -> impl Iterator<Item = ConditionalLink<'g>> + 'a

Creates an iterator over ConditionalLink instances in the direction specified.

Cycles

The links in a dependency cycle will be returned in non-dev order. When the direction is forward, if feature Foo has a dependency on Bar, and Bar has a cyclic dev-dependency on Foo, then the link Foo -> Bar is returned before the link Bar -> Foo.

Trait Implementations

impl<'g> Clone for FeatureSet<'g>

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

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'g> Debug for FeatureSet<'g>

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

Formats the value using the given formatter.

impl<'g> PartialEq for FeatureSet<'g>

fn eq(&self, other: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<'g> Eq for FeatureSet<'g>