Struct RestructureOptions 

pub struct RestructureOptions {
    pub split: SplitOptions,
    pub swap: SwapOptions,
    pub final_truncation: Option<TruncationOptions>,
}

Options for TreeTN::restructure_to multi-phase restructures.

RestructureOptions combines the three phases in the approved B2a design: a split/refinement phase, a site-transport phase, and an optional final truncation sweep after the target structure has been assembled.

Related types:

• SplitOptions controls exact splitting plus any optional final sweep inside the split primitive.
• SwapOptions controls bond truncation during site-index transport.
• TruncationOptions can be applied once at the end of the full restructure to clean up bond dimensions on the final topology.

When in doubt, start with RestructureOptions::default(): exact splitting, exact transport, and no extra final truncation sweep.

Examples

use tensor4all_treetn::{
    RestructureOptions, SplitOptions, SwapOptions, TruncationOptions,
};
use tensor4all_core::SvdTruncationPolicy;

let options = RestructureOptions::new()
    .with_split(SplitOptions::new().with_max_rank(32))
    .with_swap(SwapOptions {
        max_rank: Some(16),
        rtol: Some(1e-10),
    })
    .with_final_truncation(
        TruncationOptions::new().with_svd_policy(SvdTruncationPolicy::new(1e-12)),
    );

assert_eq!(options.split.max_rank(), Some(32));
assert!(!options.split.final_sweep);
assert_eq!(options.swap.max_rank, Some(16));
assert_eq!(options.swap.rtol, Some(1e-10));
assert_eq!(
    options
        .final_truncation
        .as_ref()
        .and_then(TruncationOptions::svd_policy),
    Some(SvdTruncationPolicy::new(1e-12))
);

Fields

split: SplitOptions

Options for the split/refinement phase.

These settings matter when a current node must be factored into multiple fragments before any fragment movement can happen. Higher max_rank, stricter svd_policy, and smaller qr_rtol preserve more fidelity but can increase intermediate bond dimensions. final_sweep should usually remain false here unless a split-only workflow is being optimized in isolation.

swap: SwapOptions

Options for the site-transport / swap phase.

This phase only moves already planned fragments across existing edges. Leaving both fields unset keeps swaps exact. Setting max_rank or rtol can control intermediate rank growth, but may introduce approximation earlier than the optional final truncation sweep.

final_truncation: Option<TruncationOptions>

Optional final truncation sweep on the fully restructured network.

Use this when the split and swap phases should remain as exact as possible, and compression should happen only after the target topology and grouping have been reached. None disables this cleanup pass.

Implementations

impl RestructureOptions

pub fn new() -> Self

Create options with exact split/swap phases and no final cleanup sweep.

Returns

A RestructureOptions value equivalent to Default::default.

Examples

use tensor4all_treetn::RestructureOptions;

let options = RestructureOptions::new();

assert!(!options.split.final_sweep);
assert_eq!(options.swap.max_rank, None);
assert_eq!(options.swap.rtol, None);
assert!(options.final_truncation.is_none());

pub fn with_split(self, split: SplitOptions) -> Self

Replace the split-phase options.

Arguments

• split - Split/refinement settings used before fragment transport.

Returns

Updated restructure options using the provided split settings.

Examples

use tensor4all_treetn::{RestructureOptions, SplitOptions};

let options = RestructureOptions::new()
    .with_split(SplitOptions::new().with_max_rank(24).with_final_sweep(true));

assert_eq!(options.split.max_rank(), Some(24));
assert!(options.split.final_sweep);

pub fn with_swap(self, swap: SwapOptions) -> Self

Replace the swap/transport options.

Arguments

• swap - Truncation settings applied during fragment movement.

Returns

Updated restructure options using the provided swap settings.

Examples

use tensor4all_treetn::{RestructureOptions, SwapOptions};

let options = RestructureOptions::new().with_swap(SwapOptions {
    max_rank: Some(12),
    rtol: Some(1e-8),
});

assert_eq!(options.swap.max_rank, Some(12));
assert_eq!(options.swap.rtol, Some(1e-8));

pub fn with_final_truncation(self, final_truncation: TruncationOptions) -> Self

Set the optional final truncation sweep.

Arguments

• final_truncation - Final cleanup sweep to run on the target topology.

Returns

Updated restructure options using the provided final sweep settings.

Examples

use tensor4all_treetn::{RestructureOptions, TruncationOptions};
use tensor4all_core::SvdTruncationPolicy;

let options = RestructureOptions::new()
    .with_final_truncation(
        TruncationOptions::new()
            .with_max_rank(10)
            .with_svd_policy(SvdTruncationPolicy::new(1e-10)),
    );

assert_eq!(
    options
        .final_truncation
        .as_ref()
        .and_then(TruncationOptions::max_rank),
    Some(10)
);

Trait Implementations

impl Clone for RestructureOptions

fn clone(&self) -> RestructureOptions

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for RestructureOptions

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

Formats the value using the given formatter.

impl Default for RestructureOptions

fn default() -> RestructureOptions

Returns the “default value” for a type.