Struct HistoryTape 

pub struct HistoryTape { /* private fields */ }

The append-forward / pop-backward garbage tape of a recording forward run. TWO stacks:

• entries — the erased-DATA deltas (register/global overwrites, output lines). These are the Landauer garbage; HistoryTape::erased_bytes/HistoryTape::len count them, and they are EMPTY for an all-abelian run. • steps — the executed program-counter trace (one entry per executed op), the control skeleton. Reverse execution walks it backward to replay the exact executed path — branches and loops fall out for free (a loop is just the trace with repeated pcs). This is control overhead (re-derivable by re-running forward, so zero erased DATA and Bennett-uncomputable), NOT part of the erased-bit count.

Implementations

impl HistoryTape

pub fn new() -> Self

A fresh, empty tape.

pub fn push(&mut self, entry: JournalEntry)

Append an erased-data delta (forward execution).

pub fn pop(&mut self) -> Option<JournalEntry>

Pop the most recent erased-data delta (reverse execution).

pub fn push_step(&mut self, pc: usize, base: usize)

Record that the op at pc (running in window base) executed (forward) — the control trace.

pub fn pop_step(&mut self) -> Option<(usize, usize)>

Pop the most recently executed (pc, base) (reverse execution walks the path backward).

pub fn len(&self) -> usize

The number of recorded erased-data deltas.

pub fn is_empty(&self) -> bool

Whether the DATA tape is empty. true after an all-abelian (bijection-only) run — the zero-erasure signature (a program may still have a non-empty control-flow steps trace).

pub fn step_count(&self) -> usize

The number of executed ops on the control-flow trace.

pub fn nondet_count(&self) -> usize

The number of recorded nondeterministic reads (clock / random) — the captured entropy count.

pub fn erased_bytes(&self) -> usize

Total erased DATA on the tape, in bytes — the Landauer energy proxy. Exactly 0 for an all-abelian run (every op self-inverts, nothing is journaled), regardless of how many times a reversible loop body ran.

pub fn landauer_bytes(&self) -> usize

The GENUINELY-irreversible information on the tape — the true Landauer (energy) number. Below HistoryTape::erased_bytes because a write that overwrote the DEFAULT (Nothing) destroyed no information: pebbling elides the recomputable scratch, and this excludes the zero-information first-writes, so a pure computation into an output measures 0.

Trait Implementations

impl Debug for HistoryTape

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

Formats the value using the given formatter.

impl Default for HistoryTape

fn default() -> HistoryTape

Returns the “default value” for a type.