List and Map Semantics

MALT exposes authenticated structure through semantic abstractions, not through runtime graph objects.

For the research framing, see MALT Abstraction. For the current UnixFS application model, see MALT UnixFS Application Model.

List

list describes complex graph nodes with ordered or indexed child references.

Read semantics:

• first-class index query
• optional measured range query over byte intervals when the implementation authenticates byte-layout metadata
• length-aware proof

Native writes:

• append
• replace
• truncate

List does not define path-resolution semantics. File layouts translate byte ranges into list queries. The current fixed-width measured list authenticates child_count, total_size, and chunk_size metadata and emits range evidence as path/@payload proof plus one measured-list list_range step carrying metadata, covered segment CIDs, and metadata/index proofs. The current prototype does not expose a first-class cryptographic range-proof API.

Map

map describes authenticated keyed or path-like relations among graph nodes.

Native reads:

• exact key lookup
• binding proof
• binding verification

Native writes:

• insert
• replace
• delete

@payload is a reserved coordinate but is optional for a generic map. A relation-only map may omit or delete it. When present, the binding is terminal and uses payload_binding proof semantics; list roots do not implicitly redirect through @payload.

UnixFS file and directory maps require @payload as a layout invariant. Other layouts may require it, omit it, or reserve additional coordinates without changing generic map semantics.

Path Resolution

Explicit path resolution is a compatibility layer above map reads. It may implement longest-prefix matching or product-specific path policy, but the map semantic owns exact key proof generation and verification.