Struct KahipOptions 

pub struct KahipOptions {
    pub seed: u64,
    pub mode: KahipMode,
    pub node_refine: bool,
}

Tunable parameters for KaHIP nested-dissection ordering.

Kept intentionally narrow while the crate is a scaffold — defaults will match KaHIP’s library defaults (seed=0, mode=Fast) once phase K6 is implemented.

Fields

seed: u64

Deterministic RNG seed. Two runs with the same seed on the same input must produce the same permutation.

mode: KahipMode

Quality / speed tradeoff. See KahipMode.

node_refine: bool

Carry the node separator through uncoarsening and refine it at every level, instead of refining the 2-way bisection and lifting to a separator once at the finest level.

The old path optimised the wrong objective at every level: minimum edge cut and minimum vertex separator are different problems. feral-metis and feral-scotch had the identical defect. KaHIP’s flow lift (flow_node_separator) is a max-flow vertex-cover reduction, too expensive to rerun per level, so the lift happens once at the coarsest level and the separator is then FM-refined down the hierarchy. Evidence in dev/research/scotch-kahip-node-separator-2026-09-18.md.

Trait Implementations

impl Clone for KahipOptions

fn clone(&self) -> KahipOptions

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for KahipOptions

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

Formats the value using the given formatter.

impl Default for KahipOptions

fn default() -> Self

Returns the “default value” for a type.