Expand description
The history tape — the Bennett/Landauer “garbage” of reverse execution.
A forward run of the VM produces (final state, tape); Vm::run_reverse walks
the instruction stream backward and consumes the tape to reconstruct the EXACT initial state.
Each information-losing op appends the minimal destroyed bits (an undo-log delta, NOT a full
snapshot); a RevClass::Bijection op appends NOTHING — it
self-inverts algebraically. So the tape’s size is the erased-bit (Landauer energy) cost, and it
is ZERO for an all-abelian run — the zero-erasure ideal the adiabatic chip is built on.
Bennett uncompute (R4) shrinks it further toward that floor.
Structs§
- History
Tape - The append-forward / pop-backward garbage tape of a recording forward run. TWO stacks:
Enums§
- Journal
Entry - One recorded delta on the
HistoryTape. Records only what a forward op DESTROYED, so reverse execution can restore it. Zero-cost/control entries (a shown line, a branch direction) carry no erased data — they are re-derivable — and so contribute nothing to the erased-bit measure.