Crate cmt 

cmt — the Canonical Mutable Tree, the single-algorithm mutable tree over the spine structural core.

CMT is the mutable peer of the append-only cml log: both are built on the spine and neither depends on the other (the structural currency between them is spine::Seal). Where CML optimizes an append-only frontier and proves consistency, CMT lets interior cells change — so it keeps no frontier and no consistency proofs (the frontier’s left-subtrees-sealed assumption is unsound under mutation). It is positional and dense, sharing the spine’s proof-spine index space, and supports:

• construct, Cmt::set / Cmt::get;
• inclusion proofs and non-membership (inclusion of the spine null constant via collapse);
• per-node multi-hash — a cell addressable under many algorithms — with retroactive per-node algorithm addition at O(log n) (Cmt::add_algorithm_at), the structural materialization of N per-algorithm roots (D11);
• a one-way Cmt::seal into the general structural spine::Seal (no unseal).

Epoch-free (D13). The CMT carries no committed timeline and no binding / combined root. The cross-tree binding of its per-algorithm member roots is the polydigest combinator’s facet, added as a wrapper over the structural Seal (polydigest(cmt)); the CMT exposes each algorithm’s raw root and member_roots, never a binding root.

Verification stays in the spine: a proof generated here is checked with spine::verify_inclusion against an authenticated (index, tree_size, arity, root).

Re-exports

pub use shape::rebalanced_bag;

pub use shape::rebalanced_skeleton;

Modules

shape

The proof-spine shape, materialized as an explicit positional tree.

Structs

Cmt

The Canonical Mutable Tree over the Merkle Spine.

Config

Configuration for a Cmt.

LeafProof

A self-contained leaf proof: a leaf hash bound to its position, ready to verify against a trusted root and the structure’s skeleton.

ProofStep

A single level in a Merkle proof path.

Seal

The general structural commitment lattice: a sealed, resumable frontier.

Enums

Error

A CMT construction or mutation error.

Traits

Hasher

Hash operations required by the Merkle Spine.

Functions

verify_inclusion

Verify an inclusion proof against a consumer-supplied skeleton.

Type Aliases

Result

A specialized Result for the mutable tree.