Struct PathCountSpec 

pub struct PathCountSpec<'a> {
    pub rel_types: Vec<Option<&'a str>>,
    pub labels: Vec<Option<&'a str>>,
    pub vertex_allow: Vec<Option<Vec<NodeId>>>,
}

Pattern description for Graph::count_linear_paths: an open directed path of one or two hops, (v0)-[t1]->(v1) or (v0)-[t1]->(v1)-[t2]->(v2), with an optional relationship type per hop and an optional label per node variable. None means unconstrained.

rel_types.len() is the hop count (1 or 2); labels.len() is the node count (hop count plus one). The two-hop count follows Cypher MATCH relationship-uniqueness semantics: the two relationships must be distinct, which only constrains self-loop assignments where one edge could fill both hops.

Fields

rel_types: Vec<Option<&'a str>>

Relationship type per hop, in path order. Length 1 or 2.

labels: Vec<Option<&'a str>>

Label per node variable, in path order. Length is rel_types.len() + 1.

vertex_allow: Vec<Option<Vec<NodeId>>>

Optional explicit allow-set of node ids per variable, in path order. A Some(ids) entry restricts that variable to ids (intersected with its label, if any); None leaves it unconstrained beyond the label. The caller resolves these sets by pushing per-vertex property predicates down into index lookups, so a filtered path count stays a kernel call instead of materializing rows. An empty vector (the default) means no variable is constrained, identical to the unfiltered path count.

Trait Implementations

impl<'a> Clone for PathCountSpec<'a>

fn clone(&self) -> PathCountSpec<'a>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'a> Debug for PathCountSpec<'a>

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

Formats the value using the given formatter.

impl<'a> Default for PathCountSpec<'a>

fn default() -> PathCountSpec<'a>

Returns the “default value” for a type.