# Changelog

All notable changes to WAFER are documented in this file.

The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

## [0.2.1] - 2026-08-06

### Fixed

- **The search order is now authoritative** (Forth 2012 §16.3.3): a word
  whose wordlist is not in the search order is no longer findable.
  Previously lookup fell back to the newest entry across all wordlists,
  making word hiding impossible. Verified against gforth and SwiftForth,
  and guarded by a cross-engine corpus program.
- **Host words validate their stack arguments.** Around 40 host-implemented
  words (`RND-SEED`, `ACCEPT`, `RESIZE`, `ALLOCATE`, `FREE`, `SEARCH`,
  `SUBSTITUTE`, `ROLL`, `M*`, `UM/MOD`, `SF@ SF! DF@ DF!`, `F. FE. FS. F~`,
  `2R@`, and friends) performed raw stack-pointer arithmetic with no
  underflow check — calling them on an empty stack silently corrupted the
  stack pointer (the compiled-code guards from 0.2.0 do not cover host
  words). All argument-taking host words now fail with a clean, CATCHable
  underflow error, enforced by a class-wide regression test.

## [0.2.0] - 2026-08-06

The usability release: introspection, source files, honest errors, and a
safety net under every compiled word.

### Added

- **Stack guards in compiled code**: under/overflow checks at the
  stack-pointer choke points of generated WASM. Faults THROW standard codes
  (`-3`..`-6`, `-44`, `-45`), are CATCHable, and print standard messages
  instead of silently corrupting memory. Default on; `wafer build` output
  stays unguarded; `WAFER_STACK_GUARDS=0|1` overrides.
- **`SEE`**: source-level decompiler. Colon words (including everything in
  `boot.fth`) show their captured verbatim source; data words show
  synthesized definitions with current values (`9 VALUE X`,
  `DEFER D ( IS DUP )`); primitives fall back to a readable IR dump —
  `SEE` never dead-ends on a defined word.
- **`SEE-IR`**: post-optimization IR view with resolved callee names and
  indented control flow — shows what the optimizer actually did.
- **`HELP`**: stack effect + one-line description for **every** word in a
  fresh VM (dictionary words and outer-interpreter tokens alike); coverage
  is enforced by a unit test, so an undocumented new word fails the build.
  User words echo their leading `( n -- n )` comment.
- **`INCLUDE` / `INCLUDED`**: nestable source-file loading with cycle
  detection, depth bound, paths relative to the including file, and
  per-level `SOURCE-ID`. The loader is injected (CLI: filesystem; web:
  defined error), so the core stays IO-free. `wafer prog.fth` now runs
  through the same machinery.
- **`MARKER` extensions**: `REMEMBER` (re-runnable marker), `EMPTY` and
  `GILD` (boot-state rollback and re-baselining). Marker rollback now also
  restores search order, wordlists, `REPLACES` substitutions, `ABORT"`
  texts, and captured word sources — enabling the `REMEMBER` + `INCLUDE`
  edit-reload loop.
- **`WORDS`**: optional substring filter (`WORDS FLOAT`), word count, and
  `WORDS ALL` — a grouped full view by wordlist plus internal words.
- **Return-stack introspection**: `.RS`, `RDEPTH`, `RP@`.
- **Tools**: `.S` honors `BASE`, `F.S`, `?`, bounds-checked `DUMP`, real
  `BYE`, named `ORDER` output.
- **CLI REPL**: persistent history (XDG state dir, `0600`), dictionary-backed
  tab completion, prefix history search on Up/Down, Ctrl-C clears the line.
- **Web REPL**: history persisted to localStorage, User Words palette,
  `BASE` indicator in the stack bar.
- **Error reporting**: uncaught `THROW` codes map to standard messages;
  `ABORT"` text prints only when uncaught; errors inside included files
  carry `file.fth:line:` context; uncaught throws are typed
  (`WaferError::UncaughtThrow`) for embedding consumers; compiled words
  carry WASM name sections, so genuine traps name the faulting word
  (`in CRASHER: wasm trap: out of bounds memory access`).
- **SwiftForth correctness lane**: the cross-engine program corpus can run
  against sf64 as an oracle (`just compare-correctness`), alongside the
  existing gforth lane and the sf64 performance lane.

### Fixed

- Multi-line command output in the CLI REPL starts on its own line
  (inline ` ok` echo only for single-line output).
- `.S` printed in decimal regardless of `BASE`.
- A bare interpreted `R>` underflowed silently (exposed by the new stack
  guards; compliance baseline updated).
- `SPACES` with a negative count now outputs nothing, per Forth 2012
  6.1.2230.

### Changed

- `wafer prog.fth` reports errors with `file:line` context and resolves
  nested `INCLUDE`s relative to the file.
- Internal words (`_`-prefixed) are flagged in the dictionary and hidden
  from `WORDS` and completion (`WORDS ALL` shows them).
- Dependencies upgraded across the board: wasmtime 43 → 47,
  wasm-encoder/wasmparser 0.246 → 0.255, plus all semver-compatible
  updates.

## [0.1.0] - 2026-08-04

Initial development line (untagged): Forth 2012 core with IR optimizer and
WASM codegen via wasm-encoder/wasmtime, ~300 words across Core, Double,
Float, String, Search-Order, Exception, and Tools word sets, Forth 2012
compliance suite, `CONSOLIDATE` whole-program recompilation, `wafer build`
AOT export (WASM / native / JS loader), browser REPL, SHA-1/256/512 words,
and cross-engine benchmark lanes against gforth and SwiftForth.

[0.2.1]: https://github.com/ok2/wafer/compare/v0.2.0...v0.2.1
[0.2.0]: https://github.com/ok2/wafer/compare/v0.1.0...v0.2.0
[0.1.0]: https://github.com/ok2/wafer/releases/tag/v0.1.0