Changelog

All notable changes to rune are recorded here. Format follows Keep a Changelog; rune is pre-1.0 and tracks milestones M1–M10 toward the Kelvin freeze (see PLAN.md).

[Unreleased]

Added

• Two registers, one AST (M4) — classic (Rust-like) and pure (Hoon-style digraph) both parse to the same AST and lower to the same Nox noun (verified: fn double(x: @ud) { x * 2 } ≡ (|= x=@ud (mul x 2))). fmt is bi-directional (--to=rune/--to=rust, either input register). Pure register executes: rune eval --pure …, or a :: register: rune file pragma.
• Instant-start interpreter — tree-walking evaluator over all 18 Nox reduction patterns; parse → lower → reduce with no compilation phase (M1).
• Subject model + cybermark scry (M2) — ~self … ~world resolve to their axis (reserved names work with or without ~); #path/@neuron/~name addresses scry the ~world slot via look. rune_subject::path_atom is the one address→key hash (real hemera), shared by the lowerer and the rune_subject::world(&[(path, val)]) slice builder. Subject::standalone() gives a resolvable ~self/~here; the CLI injects a live ~now.
• Mold system (M3) — types as normalizing functions; base molds (@ud @da @t @flag @p @tas @neuron #) plus the strata algebra tower (@nebu @kuro @jali @trop @genies); rune check validates without running. The checker runs the real molds on literals, so each enforces its own constraint (@flag = 2, @ud = [1 2] are caught), not just hard-coded heuristics.
• Acts — the pure/world boundary: opcode-16 act tags (emit query link seal subscribe host) are performed through a Host trait (eval_with_host); pure eval no-ops them via DenyHost. The seam the cyb ward plugs into (M5).
• Cell entrypoint — event::run_cell reactive loop: a gate invoked per event, emitting as it runs, threading evolving state (M5).
• rune↔prysm bridge (rune-prysm) — decodes a chunk-noun into tape::Chunks, the exact wire format prysm renders. rune eval shows emitted/returned chunks.
• CLI (rune) — a REPL (no-arg) built on reedline (the nushell line editor): persistent history, Ctrl-R search, tab-completion (builtins, acts, bound names), syntax highlighting, multi-line input, and a plain fallback for piped input. Persistent let bindings; ANSI chunk rendering; meta-commands :nox (show the lowered Nox formula), :type, :ast, :load, :env, :reset, :help (categorized). Plus run, eval, fmt, check, --version. End-to-end tests pin the command + REPL contract.

Notes

• Hint parking exists via eval_step/resume; deep cell suspend/resume (CPS) is still pending (M5b).
• The compile tier (rune-compile, M6) is a stub — TierRouter routes and caches but does not yet call trident. The interpreter path is the contract.