Struct PathSegment 

pub struct PathSegment { /* private fields */ }

One parsed step of a relationship path.

Implementations

impl PathSegment

pub fn parse(text: &str) -> Result<Self, String>

Parses Relationship[|Relationship…][:direction][+].

Errors

Returns why the text is no step: an empty alternative, one named twice, a direction other than forward, backward or either, or a direction written after an alternative other than the last.

pub fn relationships(&self) -> &[SemanticRelationship]

The relationships the step may take, in the order written.

pub fn direction(&self) -> TraversalDirection

The direction every alternative is taken in.

pub fn chain(&self) -> bool

Whether the step is taken one or more times (a trailing +).

pub fn reversed(&self) -> Self

The same step taken the other way.

pub fn shown(&self) -> String

How messages name the step’s relationships: A or A|B.

pub fn walk( &self, service: &RelationshipSelectionServiceHandle, from: &ObjectId, everything: &[ObjectId], scope: &[ObjectId], chain: bool, absent_ends: AbsentEndPolicy, ) -> Result<(BTreeSet<ObjectId>, Vec<Evidence>), RelationshipSelectionError>

The objects of scope the step reaches from from, taken once or, with chain, one or more times, with the service’s evidence.

A chain through several relationships hops between objects of everything, each hop following any alternative’s own chain, and keeps what lies in scope. from is never among the result.

Errors

Returns the service’s error for the first query it cannot answer completely.

Trait Implementations

impl Clone for PathSegment

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PathSegment

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

Formats the value using the given formatter.

impl Eq for PathSegment

impl PartialEq for PathSegment

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for PathSegment