Struct StudyState 

pub struct StudyState { /* private fields */ }

A read-only snapshot of a study’s history, handed to samplers and pruners.

Both crate::Sampler::suggest and crate::Pruner::should_prune receive a StudyState rather than a single trial so that adaptive samplers (TPE) and cross-trial pruners (median, successive-halving) have everything they need through one channel. Under parallel execution this snapshot is deliberately slightly stale — see [crate::Study::optimize_parallel].

Implementations

impl StudyState

pub fn new(direction: Direction, trials: Vec<Trial>) -> Self

Builds a snapshot from the study direction and its trials so far.

pub fn direction(&self) -> Direction

The optimization direction of the owning study.

pub fn trials(&self) -> &[Trial]

All trials in the snapshot, in trial-number order.

pub fn completed_trials(&self) -> impl Iterator<Item = &Trial>

Trials that completed successfully and carry a final value.

pub fn n_completed(&self) -> usize

Number of completed trials — used by samplers/pruners for warmup gates.

pub fn intermediate_values_at(&self, step: usize) -> Vec<f64>

Intermediate values reported at exactly step across all trials that reached it (completed or pruned). Used by MedianPruner.

pub fn values_at_or_after(&self, step: usize) -> Vec<f64>

Values of all trials that reached resource >= step, taken at the first step at or after step. Used by rung-based pruners.

pub fn best_trial(&self) -> Option<&Trial>

The best completed trial under the study direction, if any.

Trait Implementations

impl Clone for StudyState

fn clone(&self) -> StudyState

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for StudyState

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

Formats the value using the given formatter.