Interface: LtpState

The reducer's immutable session state. Every ltpReduce call returns a new, frozen LtpState; the previous one is never mutated.

Properties

expectedFrame

readonly expectedFrame: number

The next frame number the receiver expects (1 → … → 7 → 0 → …), meaningful in transfer. A trusted frame carrying this number is accepted and appended; any other number is a duplicate retransmit (idempotent re-ACK) or an out-of-sequence frame (rejected with NAK), never silently bridged.

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lastAcceptedFrame?

readonly optional lastAcceptedFrame?: number

The frame number of the last frame accepted into the current record, used to recognise a duplicate retransmit; undefined before the first frame of a transfer is accepted.

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openRecord

readonly openRecord: Uint8Array

The bytes accumulated so far for the in-progress record: the concatenation of the ETB frames accepted since the last ETX. Empty when no record is open. These bytes are never delivered on their own: only an ETX completes a record, at which point they (plus the final frame's text) become one entry in LtpState.records. An EOT or an ENQ restart discards them unread.

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phase

readonly phase: LtpPhase

The current protocol phase.

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recordOpen

readonly recordOpen: boolean

true when a record is mid-reassembly (an ETB frame was accepted, awaiting its ETX).

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records

readonly records: readonly Uint8Array<ArrayBufferLike>[]

The reassembled bytes of every complete record delivered so far in the session (each closed by an ETX frame with a clean run). Concatenate these and hand them to parseAstmRecords to get the message. Only trusted, in-sequence frames contribute; a rejected or partial record never appears.