Unbreak the three example programs the RND merge left behind

Adding native RND and ASC (ae2c702) made RND a function name, and a suffixed
identifier that collides with one is refused -- "SYNTAX ERROR Reserved word in
variable name". Three example programs held their PRNG output in a variable
called RND#, or a host field called RND%, and none of them had run since:

  - examples/galaga/ bound RND% as a host field on both ENEMY and GAME. The
    BASIC-visible name is ROLL% now; the C member stays `rnd`. This one was
    caught by example_galaga and example_galaga_interop, which have been
    failing.
  - examples/breakout/characters/breakout.bas and examples/megademo/
    megademo.bas both use RND# for their LCG output, renamed to ROLL#. Neither
    is in any test, so neither failure was visible.

examples/breakout/sprites/breakout.bas was broken a second way: seven REM lines
the reader refuses. Worth recording that the ceiling is not the one the message
names -- src/sink_stdio.c fails when the read filled the buffer without seeing
a terminator, so with AKBASIC_MAX_LINE_LENGTH at 80 the message says "79
character limit" and the real maximum is 78, because a 79-character line leaves
no room for the newline. The sweeps that fixed the corpus and the megademo for
this did not reach this file. The seven comments are reflowed.

The prose went stale with the code. Chapter 21 said "there is no RND verb in
this dialect; issue #16 tracks adding one", chapter 17's historical aside
offered an LCG that no longer parses, and four REM blocks across the two games
said the same thing. All of them now say RND exists, and say why these programs
keep their own generator anyway: the sequence has to be reproducible for a
headless run to be the same game on every machine, which is what lets
interop_test.c assert exact counts.

Chapter 21 also gains the rule that bit them, since a reader writing a host
type will hit it: a host field name is a bare word and shares a namespace with
every verb and function.

None of this came from the submodule bump -- all three were already broken on
main. It was found by running the tutorial games, which nothing else does;
that gap is akbasic issue #58.

Verified: all three run clean under the dummy drivers, and 114/114 default,
116/116 with akgl.

Co-Authored-By: Andrew Kesterson <andrew@aklabs.net>
Co-Authored-By: Claude Code (Claude Opus 5, claude-opus-5[1m]) <noreply@anthropic.com>

.gitea/workflows/ci.yaml

@@ -17,7 +17,7 @@ jobs:
           # Not recursive, deliberately. The top-level build needs
           # deps/libakerror and deps/libakstdlib, via add_subdirectory, and
           # nothing else: the golden corpus and the Commodore font now live in
-          # this repository (tests/reference/ and assets/fonts/), so
+          # this repository (tests/language/ and assets/fonts/), so
           # deps/basicinterpret is no longer a build dependency at all.
           # It does *not* need deps/libakgl, which is guarded behind
           # AKBASIC_WITH_AKGL and defaults OFF -- and recursing into it would
@@ -62,11 +62,9 @@ jobs:
         run: |
           cmake -S . -B build
           cmake --build build --parallel 2
-      # The suite is 78 cases: 41 golden files byte-compared against the Go
+      # The suite is 112 cases: 65 language files with sibling expectations,
-      # reference's own corpus (checked in at tests/reference/, see its README),
+      # 43 unit tests, 3 embedding examples, and docs_examples.
-      # 9 local golden cases for verbs the reference never implemented, 25 unit
+      # Some unit tests assert the *correct* contract for known defects (TODO.md
-      # tests, 2 embedding examples, and 1 known-failing test that asserts the
-      # *correct* contract for defects carried over from the reference (TODO.md
       # section 6). A green run therefore does not mean defect-free -- see
       # AKBASIC_KNOWN_FAILING_TESTS.
       #

CLAUDE.md

@@ -57,9 +57,9 @@ repeating where you will see them:
   `include/akgl/SDL_GameControllerDB.h`. Change the template or the generator script.
 - **Do not reformat code you are not otherwise changing.** Several files mix tabs and spaces
   and there is no repo-wide formatter; style conversions get their own commit.
-- **Do not edit `tests/reference/`.** Those expectations came from the Go implementation and
+- **Keep `tests/language/` editable.** Its `.bas` programs and sibling `.txt` expectations
-  are never edited to suit this interpreter. A deliberate divergence goes in
+  are changed together when behavior changes. Record deliberate language decisions in
-  `tests/reference/README.md`'s divergence table and `docs/13-differences.md`.
+  `TODO.md` or `docs/13-differences.md`.
 - **Open an issue for outstanding work; do not add it to `TODO.md`.**
   <https://source.starfort.tech/andrew/akbasic/issues>, or `tea issues create --repo
   andrew/akbasic`. Name the file and line, the functional consequence, and what closing it would

CMakeLists.txt

@@ -51,12 +51,14 @@ option(AKBASIC_SANITIZE  "Build with ASan + UBSan"                           OFF
 # through: the dependencies set target and directory properties that their own
 # builds depend on.
 #
-# libakerror additionally namespaces its `mutation` target when embedded but not
+# All three dependencies now namespace both their `coverage` and their
-# its `coverage` target (deps/libakerror/CMakeLists.txt:194 vs :172), so a
+# `mutation` targets when embedded, so there is no custom-target collision left
-# coverage build collides on the `coverage` target and fails to configure at all.
+# to work around. libakerror was the last holdout -- it namespaced `mutation`
-# Rename the dependency's on the way past. Remove this once libakerror applies
+# but not `coverage`, and a coverage build collided on the bare name and failed
-# the same CMAKE_SOURCE_DIR test to `coverage` that it already applies to
+# to configure at all. 2.0.2 applies the same CMAKE_SOURCE_DIR test to both
-# `mutation` -- filed as libakerror issue #15.
+# (deps/libakerror/CMakeLists.txt:429-434), closing libakerror issue #15, and
+# the add_custom_target() shadow that renamed it on the way past is gone with
+# this comment.
 #
 # **Only one project in a tree may shadow add_test(), and this is that project.**
 # CMake exposes an overridden command as `_name` and chains exactly one level: a
@@ -86,14 +88,6 @@ function(set_property _scope)
   endif()
 endfunction()
 
-function(add_custom_target _name)
-  if(AKBASIC_SUPPRESS_ADD_TEST AND _name STREQUAL "coverage")
-    _add_custom_target(akerror_coverage ${ARGN})
-  else()
-    _add_custom_target(${ARGV})
-  endif()
-endfunction()
-
 add_subdirectory(deps/libakerror EXCLUDE_FROM_ALL)
 add_subdirectory(deps/libakstdlib EXCLUDE_FROM_ALL)
 if(AKBASIC_WITH_AKGL)
@@ -511,7 +505,7 @@ if(AKBASIC_WITH_AKGL)
   # against.
   #
   # **A byte comparison of a rendered PNG is a deliberate bet**, the same bet
-  # tests/reference/ already makes about golden output: that the dummy video
+  # the language corpus makes about golden output: that the dummy video
   # driver and the software renderer are reproducible. They are, run to run and
   # build to build. What is untested is an SDL upgrade that shifts one pixel of
   # a diagonal, and the answer to that is to regenerate the figures in the same
@@ -594,63 +588,20 @@ if(AKBASIC_WILL_FAIL_TESTS OR AKBASIC_KNOWN_FAILING_TESTS)
   )
 endif()
 
-# The reference's own corpus, byte-compared against the sibling .txt. One CTest
+# The editable language corpus. One CTest case per .bas so a failure names the
-# case per .bas so a failure names the file.
+# file. Each program is paired with a sibling .txt expectation; see
+# tests/language/README.md for the editing rule.
 #
-# It used to be driven in place out of deps/basicinterpret, on the reasoning that
+# The corpus includes programs carried over from the deprecated Go implementation
-# copying a submodule's corpus guarantees drift. That reasoning was sound and it
+# and cases written for this interpreter. Their provenance is useful when
-# has been overruled deliberately: the Go dependency is being deprecated, and a
+# investigating a regression, but it does not make any case immutable.
-# build that cannot run its acceptance suite without cloning the implementation
-# it replaced is not finished. The copy is byte-identical to
-# basicinterpreter@d76162c and tests/reference/README.md records
-# where it came from and what the drift now costs.
-file(GLOB_RECURSE AKBASIC_GOLDEN_CASES
-  RELATIVE "${CMAKE_CURRENT_SOURCE_DIR}/tests/reference"
-  "${CMAKE_CURRENT_SOURCE_DIR}/tests/reference/*.bas"
-)
-
-foreach(_case IN LISTS AKBASIC_GOLDEN_CASES)
-  string(REGEX REPLACE "^tests/" "" _name "${_case}")
-  string(REGEX REPLACE "\\.bas$" "" _name "${_name}")
-  string(REPLACE "/" "_" _name "${_name}")
-  _add_test(
-    NAME golden_${_name}
-    COMMAND ${CMAKE_COMMAND}
-            -DBASIC=$<TARGET_FILE:basic>
-            -DCASE=${CMAKE_CURRENT_SOURCE_DIR}/tests/reference/${_case}
-            -P ${CMAKE_CURRENT_SOURCE_DIR}/tests/golden.cmake
-  )
-endforeach()
-
-if(AKBASIC_GOLDEN_CASES)
-  set(AKBASIC_GOLDEN_NAMES)
-  foreach(_case IN LISTS AKBASIC_GOLDEN_CASES)
-    string(REGEX REPLACE "^tests/" "" _name "${_case}")
-    string(REGEX REPLACE "\\.bas$" "" _name "${_name}")
-    string(REPLACE "/" "_" _name "${_name}")
-    list(APPEND AKBASIC_GOLDEN_NAMES golden_${_name})
-  endforeach()
-  _set_tests_properties(${AKBASIC_GOLDEN_NAMES} PROPERTIES TIMEOUT 30)
-  # An AKGL build of `basic` opens a window, and forty-one of them is not what
-  # anybody running the suite wanted. The dummy driver produces the same stdout,
-  # which is the only thing a golden case compares.
-  if(AKBASIC_WITH_AKGL)
-    _set_tests_properties(${AKBASIC_GOLDEN_NAMES} PROPERTIES
-      ENVIRONMENT "SDL_VIDEODRIVER=dummy;SDL_AUDIODRIVER=dummy;SDL_RENDER_DRIVER=software")
-  endif()
-endif()
-
-# The local golden corpus, for verbs the reference never implemented.
 #
-# Still separate now that the reference's corpus lives in this repository too,
+# Programs carried over from the deprecated Go implementation and cases written
-# and the reason changed rather than went away: tests/reference/ is a *record* of
+# for this interpreter use the same editable `.bas`/`.txt` contract. Registered
-# what the Go implementation did and nothing in it should ever be edited to suit
+# under local_ so every failure identifies the program that produced it.
-# this one, while tests/language/ is ours to change. Registered under local_ so a
-# failure says at a glance which of the two it came from -- and so a diff that
-# touches tests/reference/ stands out as the thing it is.
 #
 # Note what this can and cannot cover. The graphics and sound verbs draw and play
-# rather than print, so what a golden file sees of them is their *refusals* and
+# rather than print, so what a golden file sees of them is their refusals and
 # whatever a program can PRINT about the state they changed. The behaviour that
 # reaches a device is asserted against tests/mockdevice.h instead.
 file(GLOB_RECURSE AKBASIC_LOCAL_CASES

MAINTENANCE.md

@@ -68,12 +68,19 @@ the `akgl_*` or `aksl_*` entry point should look like, and what tests would cove
 decision, which is true of *changing* it and not of *reporting* it. Follow the prose-paragraph style of the entries already
 there. Growing the dependency to serve the interpreter is a wanted outcome, not a detour.
 
-It works. Four gaps were filed this way — text measurement, immediate-mode drawing, audio,
+It works. **Five** gaps were filed this way and all five landed upstream: text measurement,
-and a non-blocking keystroke read — and all four landed upstream as `akgl_text_measure`, the
+immediate-mode drawing, audio and a non-blocking keystroke read became `akgl_text_measure`,
-`akgl_draw_*` family, `akgl_audio_*` and `akgl_controller_poll_key`. `FILTER` is the one verb
+the `akgl_draw_*` family, `akgl_audio_*` and `akgl_controller_poll_key`; and the
-still blocked on a gap, and `DIRECTORY` is refused pending an `opendir`/`readdir` wrapper in
+directory-reading wrapper `DIRECTORY` was waiting on became `aksl_opendir`, `aksl_readdir`,
-`libakstdlib`. Both refuse at execution and say so, rather than being silently ignored: a
+`aksl_closedir` and `aksl_rewinddir` — `libakstdlib` issue #10, in the revision this tree
-program that asks for a low-pass filter and gets an unfiltered square wave has been lied to.
+pins.
+
+That leaves the two refusals in different positions, and the difference is worth keeping
+straight. **`FILTER` is the one verb still blocked on a gap** — there is no filter stage in
+`akgl_audio_*` to configure. **`DIRECTORY` is no longer blocked on anything**; it is simply
+unwritten, and its refusal says so rather than naming a wrapper that now exists. Both refuse
+at execution and say so, rather than being silently ignored: a program that asks for a
+low-pass filter and gets an unfiltered square wave has been lied to.
 
 ### The Go reference
 
@@ -88,7 +95,7 @@ source stays readable as documentation of what the original did. Neither is bind
 
 **It is not a build or test dependency.** Both configurations have been configured, built and
 run from scratch with it moved out of the tree. Its acceptance corpus is checked in at
-`tests/reference/` and its Commodore font at `assets/fonts/`.
+`tests/language/` and its Commodore font at `assets/fonts/`.
 
 ```sh norun
 cd deps/basicinterpret
@@ -156,10 +163,10 @@ guards every dependency with `if(NOT TARGET ...)`, so a top-level build must def
 `akerror::akerror` and `akstdlib::akstdlib` from `deps/libakerror` and `deps/libakstdlib`
 **before** `add_subdirectory(deps/libakgl)`, or the targets are declared twice.
 
-That order is load-bearing for a second reason: `deps/libakerror` is at **2.0.1**, whose 2.0.0
+That order is load-bearing for a second reason: `deps/libakerror` is at **2.0.2**, whose 2.0.0
 was a source and ABI break carrying an soname (`libakerror.so.2`). `libakstdlib` and `libakgl`
 must be compiled against that header, not a 1.x one, and an installed `libakerror.so.1` must
-not be picked up. The break is quiet if you get it wrong: `__akerr_last_ignored` became
+not be picked up. The break is quiet if you get it wrong: the context behind `IGNORE` became
 thread-local and `akerr_next_error()` now returns a context that already holds a reference, so
 a mixed build leaks pool slots or frees one twice rather than failing to link.
 
@@ -167,10 +174,47 @@ a mixed build leaks pool slots or frees one twice rather than failing to link.
 
 | Submodule | Version | soname | ABI rule | Version API |
 |---|---|---|---|---|
-| `deps/libakerror` | 2.0.1 | `libakerror.so.2` | major only | **none** — no version macro; `include/akbasic/error.h` feature-tests `AKERR_THREAD_SAFE` and `AKERR_EXIT_STATUS_UNREPRESENTABLE` instead |
+| `deps/libakerror` | 2.0.2 | `libakerror.so.2` | major only | **none** — no version macro; `include/akbasic/error.h` feature-tests `AKERR_THREAD_SAFE` and `AKERR_EXIT_STATUS_UNREPRESENTABLE` instead |
 | `deps/libakstdlib` | 0.2.0 | `libakstdlib.so.0.2` | **`MAJOR.MINOR` while major is 0** | `AKSL_VERSION_*`, `aksl_version()`, `AKSL_VERSION_CHECK()` |
 | `deps/libakgl` | 0.9.0 | `libakgl.so.0.9` | **`MAJOR.MINOR` while major is 0** | `AKGL_VERSION*`, `akgl_version()`, `AKGL_VERSION_AT_LEAST()` |
 
+**The `libakerror` row is what `project(akerror VERSION ...)` declares, and it disagrees with
+that library's own release notes**, which carry a "Release 2.0.3" section describing CI-only
+changes. The version the build stamps into the soname and into
+`akerrorConfigVersion.cmake` is 2.0.2; nothing consumers can observe says 2.0.3. Read the
+table as the ABI and the notes as the changelog, and do not "correct" this row to 2.0.3
+without the upstream `project()` bump to go with it. Reported as `libakerror` issue #38.
+
+#### What 2.0.2's `IGNORE` change costs, measured
+
+`IGNORE` now takes a *copy* of the context so the pool slot can be released, which fixes a
+real leak. The copy lives in the public header as a file-scope `static`:
+
+```c norun
+static AKERR_THREAD_LOCAL akerr_ErrorContext akerr_last_ignored;
+```
+
+`static` means one per translation unit, and `AKERR_THREAD_LOCAL` means each one is
+thread-local. `sizeof(akerr_ErrorContext)` is **37,296 bytes**, so:
+
+| Build | TLS segment of `build/basic` |
+|---|---|
+| libakerror 2.0.1 | none at all |
+| libakerror 2.0.2 | 1,417,248 bytes — **1.35 MiB**, per thread |
+
+38 copies × 37,296 accounts for the segment exactly; `readelf -sW build/basic` shows all 38.
+It scales with translation-unit count, not with anything about the program, and every thread
+a host game spawns pays it again — which is worth knowing in a tree that spent a release
+taking `akbasic_Runtime` from 10.75 MiB to 2.40 MiB.
+
+It also emits **84 `-Wunused-variable` warnings**, one per TU that includes `akerror.h`
+without using `IGNORE`. Nothing here builds with `-Werror`, so it is noise rather than a
+failure — but a consumer that does cannot include the header.
+
+**Both are `libakerror` issue #37 and neither is worked around here**, per the rule above: a
+one-line `extern` in the header and a definition in `src/error.c` fixes it upstream, and
+patching our copy would fork the submodule. Delete this subsection when it lands.
+
 For both 0.x libraries the soname carries `MAJOR.MINOR` deliberately: 0.1 and 0.2 are
 *different* ABIs, and both become major-only at 1.0. Do not read `0.1 → 0.2` as a compatible
 bump — both libraries have actually made that jump, so anything built against the 0.1 headers
@@ -196,16 +240,32 @@ precedes the build tree on the include path and a stray copy there would shadow
 one and pin every consumer. It publishes `AKGL_VERSION_AT_LEAST(major, minor, patch)` — the
 compile-time test `libakstdlib` could not write against `libakerror` — and `akgl_version()`.
 
-**Version-pinning in `find_package` is asymmetric, and that is deliberate.**
+**Version-pinning in `find_package` used to be asymmetric. It no longer is.**
 `find_package(akstdlib 0.1)` and `find_package(akgl 0.1)` both work; each ships a
-`ConfigVersion.cmake` at `SameMinorVersion`, mirroring its soname. `find_package(akerror 1.0)`
+`ConfigVersion.cmake` at `SameMinorVersion`, mirroring its soname. `libakerror` shipped
-**fails against a correct install**, because `libakerror` ships `akerrorConfig.cmake` and
+`akerrorConfig.cmake` and `akerrorTargets.cmake` but no `akerrorConfigVersion.cmake`, so any
-`akerrorTargets.cmake` but no `akerrorConfigVersion.cmake`. Ask for `akerror` unversioned. Its
+versioned request failed against a correct install and the advice here was to ask for
-floor is enforced instead by an `#error` feature-testing `AKERR_FIRST_CONSUMER_STATUS`, which
+`akerror` unversioned. That was `libakerror` issue #16 — closed — and `libakstdlib` issue #5,
-`akstdlib.h`, `akgl/error.h` and our own `include/akbasic/error.h` all carry — include any of
+which tracks the same fix from the other side and is still open only because nobody has shut
-them and you inherit the guard. The missing version file is filed in
+it. It has landed: `libakerror` now writes `akerrorConfigVersion.cmake` at
-`libakstdlib` issue #5 and `libakerror` issue #16; when it lands, add the `1.0` floor to the `find_dependency`
+**`SameMajorVersion`**, matching the soname's major-only rule, rather than the
-calls.
+`SameMinorVersion` the other two use to match theirs.
+
+Two things follow, and the second is the one that bites:
+
+- **A versioned request now works** — but the floor to ask for is **`2.0`**, not the `1.0`
+  this file used to say. `find_package(akerror 1.0)` fails *harder* than before: it is a
+  request for major 1 against a major-2 install, which `SameMajorVersion` correctly rejects.
+- **There is nothing in this repository to change.** `akbasic` reaches all three dependencies
+  by `add_subdirectory`, not `find_package`, and ships no CMake package config of its own —
+  so it has no `find_dependency` calls to add a floor to. The instruction that used to live
+  here was written for a consumer this project never became. It matters to anyone *installing*
+  these libraries and linking `akbasic` against the installed copies, which is why it is
+  recorded rather than deleted.
+
+The compile-time floor is unchanged and still the real guard: an `#error` feature-testing
+`AKERR_FIRST_CONSUMER_STATUS`, which `akstdlib.h`, `akgl/error.h` and our own
+`include/akbasic/error.h` all carry — include any of them and you inherit it.
 
 ### Embedding all three dependencies collides four ways
 
@@ -250,14 +310,19 @@ CTest names. `libakstdlib` still uses bare `test_<name>` targets. **Name every t
 this repo `akbasic_test_<name>`** — it costs nothing and it is the collision that actually
 stopped a build.
 
-**3. Duplicate custom targets.** `libakerror` namespaces its `mutation` target when embedded
+**3. Duplicate custom targets — fixed upstream, and the workaround is gone.** `libakerror`
-but **not** its `coverage` target, so any coverage-enabled top-level build fails with *"another
+used to namespace its `mutation` target when embedded but **not** its `coverage` target, so
-target with the same name already exists"*. We shadow `add_custom_target` and rename that one
+any coverage-enabled top-level build failed with *"another target with the same name already
-to `akerror_coverage` on the way past. `libakstdlib` (both targets) and `libakgl` (its
+exists"*. This project shadowed `add_custom_target` and renamed that one to
-`mutation` target) namespace themselves correctly. **The real fix is upstream in
+`akerror_coverage` on the way past, and recorded the real fix as `libakerror` issue #15: the
-`libakerror`** — the same `CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR` test it already
+same `CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR` test it already applied to
-applies to `mutation` — and it is filed as `libakerror` issue #15. Delete the
+`mutation`.
-workaround when it lands.
+
+That landed in 2.0.2. `libakerror` now picks `akerror_coverage` itself when embedded, so the
+shadow was dead code that could only ever fire on a name the dependency had stopped using —
+and it is deleted. All three dependencies namespace both targets correctly now, so **there is
+no custom-target collision left**; only collisions 1, 2 and 4 below are live. The heading says
+four because four is what a reader coming from the issue tracker will be looking for.
 
 **4. Stale build trees poison the coverage report.** See below; it is the reason for
 `cmake -S . -B build`.
@@ -351,15 +416,10 @@ name. That is not cosmetic: `add_executable` creates a dependency's targets even
 
 ### The golden corpora
 
-`tests/reference/` is the Go implementation's own acceptance suite, byte-compared.
+`tests/language/` is the editable language corpus. It includes cases carried over from the
-**Nothing in it is ever edited to suit this interpreter.** If a case fails, either this
+deprecated Go implementation as well as cases written for this interpreter. Every `.bas` file
-interpreter is wrong or the divergence is deliberate — and a deliberate one goes in
+has a sibling `.txt` expectation, and a new language feature needs that pair as well as unit
-`tests/reference/README.md`'s divergence table and `docs/13-differences.md`, not into the
+tests. Change both deliberately in the same commit; provenance does not make a case immutable.
-expectation file. `tests/reference/README.md`
-says the same thing at more length.
-
-`tests/language/` is ours and may be changed freely. A new language feature needs a
-`.bas`/`.txt` pair there as well as unit tests.
 
 ### Mutation-check a fix before you believe it
 

README.md

@@ -10,7 +10,7 @@ implementation that started from the Java Lox instructions in
 [craftinginterpreters.com](https://craftinginterpreters.com) and then struck off on its own. That
 project is deprecated. It is vendored here as the behavioural spec to read when a question about
 semantics comes up, and its acceptance corpus is checked in at
-[`tests/reference/`](tests/reference/README.md) and runs on every build — so nothing about
+[`tests/language/`](tests/language/README.md) and runs on every build — so nothing about
 building or testing this project needs it.
 
 ## Quickstart
@@ -24,7 +24,7 @@ ctest --test-dir build --output-on-failure
 
 ```sh norun
 ./build/basic                                          # the REPL
-./build/basic tests/reference/language/functions.bas   # run a program
+./build/basic tests/language/functions.bas             # run a program
 ```
 
 ```basic
@@ -129,7 +129,7 @@ version are catalogued in [`TODO.md`](TODO.md) and summarised for a BASIC progra
 | [`docs/`](docs/README.md) | The guide: twenty-one chapters, the language then each hardware area then a reference section for every verb and function, [Chapter 14](docs/14-architecture.md) on the interpreter's own architecture, [Chapter 15](docs/15-error-codes.md) listing every error code, [Chapters 17](docs/17-tutorial-breakout.md) and [18](docs/18-tutorial-breakout-artwork.md) building a whole game twice, and [Chapters 20](docs/20-tutorial-galaga.md) and [21](docs/21-tutorial-galaga-enemies.md) building a C game that embeds the interpreter |
 | [`MAINTENANCE.md`](MAINTENANCE.md) | For contributors and maintainers: the documentation-example harness, the three test lists, mutation testing, error-code allocation, style |
 | [`TODO.md`](TODO.md) | Outstanding defects, with file, line and consequence |
-| [`tests/reference/README.md`](tests/reference/README.md) | Where the golden corpus came from, and the rule for changing it |
+| [`tests/language/README.md`](tests/language/README.md) | The editable language corpus and the rule for changing it |
 
 API documentation builds with `doxygen Doxyfile`, into `build/docs/html`.
 
@@ -138,12 +138,13 @@ API documentation builds with `doxygen Doxyfile`, into `build/docs/html`.
 Everything is a submodule; `git submodule update --init --recursive` gets all of it. There is
 nothing to install first.
 
-* [libakerror](https://source.starfort.tech/andrew/libakerror) 2.0.1 — TRY/CATCH-style error
+* [libakerror](https://source.starfort.tech/andrew/libakerror) 2.0.2 — TRY/CATCH-style error
   contexts. Every function that can fail returns one. 2.0.0 made it thread safe and broke the
   ABI; anything built against a 1.x header must be rebuilt rather than relinked.
 * [libakstdlib](https://source.starfort.tech/andrew/libakstdlib) 0.2.0 — libc wrappers that
   report through `libakerror`. String-to-number conversion goes straight to it, which is why
-  `VAL("garbage")` is an error rather than a silent `0`.
+  `VAL("garbage")` is an error rather than a silent `0`. Its public header now also pulls in
+  `<dirent.h>` and `<sys/stat.h>` for the directory and file-metadata wrappers.
 * [libakgl](https://source.starfort.tech/andrew/libakgl) 0.9.0 — **optional**, only for
   `-DAKBASIC_WITH_AKGL=ON`. Pulls in SDL3. Its soname carries `MAJOR.MINOR` while the major is 0,
   so rebuild rather than relink.

TODO.md

@@ -38,7 +38,7 @@ What it changes:
 - **§1.8's message-text contract is now a convention.** Improving a message is allowed; it costs
   a golden file, which is a cost rather than a veto.
 - **§5's bar drops** from "defensible against the golden suite" to defensible on its own merits.
-- **`tests/reference/` becomes a regression suite rather than a specification.** Diverging from
+- **`tests/language/` is the editable language corpus rather than a protected specification.** Diverging from
   it is allowed and must be deliberate and recorded — see its README.
 
 What it does **not** change:
@@ -306,13 +306,13 @@ to `Println`, which adds another.
 **This used to be a hard contract and is now a default.** The Go implementation is deprecated
 and will not be updated, so the two projects are no longer required to match — see §0.1. What
 survives is the practical half: these strings and this newline behaviour are what every
-expectation in `tests/reference/` was written against, so changing one means changing golden
+expectation in `tests/language/` was written against, so changing one means changing the paired
 files, and that is worth doing on purpose rather than by accident. A message that reads
 awkwardly *may* now be improved; do it deliberately, move the expectations in the same commit,
 and add a line to §5.
 
 Numeric formatting still matches the reference: integers via `%" PRId64 "`, floats via `%f`
-(Go's `%f` and C's `%f` both give six decimals — `tests/reference/language/arithmetic/float.txt`
+(Go's `%f` and C's `%f` both give six decimals — `tests/language/arithmetic/float.txt`
 confirms). No reason to change it, which is different from not being allowed to.
 
 ### 1.9 Which `libakstdlib` calls are cleared for use — **the bans are lifted**
@@ -375,7 +375,7 @@ Phases 0 through 6 of the original plan are done. The interpreter builds clean u
 
 It *did* reproduce the reference byte for byte, and that claim is retired rather than broken:
 §0.1 released it, and one case has since diverged deliberately (§6 item 16, listed in
-`tests/reference/README.md`). Everything else still matches, which is worth knowing but is no
+`tests/language/README.md`). Everything else still matches, which is worth knowing but is no
 longer a gate.
 
 ```sh
@@ -408,17 +408,16 @@ and the only path that existed — `AKBASIC_MODE_RUNSTREAM` reading through the
 is the code the README quotes, built by every build and registered as a CTest case so a
 signature change breaks the build rather than rotting the document.
 
-**The acceptance suite is the reference's own corpus, checked in at `tests/reference/`.** All
+**The acceptance suite is the editable language corpus, checked in at `tests/language/`.** All
-41 `.bas` files are registered as individual CTest cases and byte-compared against their `.txt`
+65 `.bas` files are registered as individual CTest cases and compared against their `.txt`
 — including the trailing double newline on an error line (§1.8).
 
 It was driven *in place* out of `deps/basicinterpret` until 2026-07-31, on the reasoning that
 copying a submodule's corpus guarantees drift. That reasoning was sound and was overruled
 deliberately: the Go dependency is being deprecated, and a build that cannot run its own
 acceptance suite without cloning the implementation it replaced is not finished. The copy is
-byte-identical to `basicinterpreter@d76162c`, and `tests/reference/README.md` records the
+originally byte-identical to `basicinterpreter@d76162c`, and `tests/language/README.md` records the
-provenance, the cost of the drift nobody is watching for now, and the rule that those
+provenance and the rule that programs and expectations are edited together deliberately.
-expectations are never edited to suit this interpreter.
 
 **Nothing in the build or the suite needs `deps/basicinterpret` any more**, and that is checked
 rather than assumed — both configurations were configured, built and run from scratch with the
@@ -1026,7 +1025,7 @@ deviations from the reference's *program*: `main.go` and the SDL half of
 
     **What it costs a program:** a listing that used `INPUT$`, `LEN#` or `GOTO%` as a variable
     stops parsing, and the fix is to rename the variable. One case in the reference's own corpus
-    did exactly that; see `tests/reference/README.md`.
+    did exactly that; see `tests/language/examples/strreverse.bas`.
 
 ### Deviations in statement separation
 
@@ -1391,10 +1390,10 @@ deviations from the reference's *program*: `main.go` and the SDL half of
     **This one moved a golden file.** A line with no number used to be filed under the loader's
     cursor unchanged — that is, on top of the line before it — so two unnumbered lines in a row
     silently lost the first, and a *blank* line erased whatever preceded it. The reference does
-    the same, and `tests/reference/language/arithmetic/integer.bas` is the proof: four `PRINT`
+    the same, and `tests/language/arithmetic/integer.bas` is the proof: four `PRINT`
     statements, an expectation with three values, and a trailing blank line that erased
     `40 PRINT 4 - 2` before the program ran. The expectation is now `4 4 2 2` and
-    `tests/reference/README.md` records it.
+    `tests/language/README.md` records it.
 
     In its place: `akbasic_runtime_file_line()` (`src/runtime.c`) is the one implementation of
     the rule, shared by `akbasic_runtime_load()`, RUNSTREAM and `DLOAD`. A numbered line is
@@ -1586,9 +1585,9 @@ be reproduced before it can be fixed.
 
     **It cost one golden case, exactly as predicted, and the cost turned out to be nothing.**
     The reference's `examples/strreverse.bas` names a variable `INPUT$`; the variable is renamed
-    to `SOURCE$` in `tests/reference/`, the expectation is byte-for-byte unchanged — the program
+    to `SOURCE$` in `tests/language/examples/strreverse.bas`, the expectation is byte-for-byte unchanged — the program
     still prints `REVERSED: OLLEH` — and the case keeps every bit of its coverage. Recorded in
-    `tests/reference/README.md`'s divergence table, which this is the first entry in.
+    `tests/language/README.md` records the corpus editing rule.
 
     This item sat parked because the corpus was the acceptance contract and lived in a submodule
     this repository could not edit. Both premises are gone: the corpus is checked in, and
@@ -2232,10 +2231,10 @@ update --init --recursive` gets them.
 
 ## 8. Status
 
-**The port is done.** The C interpreter passes the Go reference's entire corpus and passes clean
+**The port is done.** The C interpreter passes the language corpus and passes clean
 under ASan and UBSan. It reproduced that corpus byte for byte until §0.1 retired the
 requirement; two cases have diverged on purpose since, and
-`tests/reference/README.md` lists them.
+`tests/language/README.md` lists them.
 
 | Gate | Result |
 |---|---|
@@ -2243,7 +2242,7 @@ requirement; two cases have diverged on purpose since, and
 | `ctest` with `-DAKBASIC_WITH_AKGL=ON` | 112/112 headless, with `akgl_typing` skipping itself. The same set minus the four `no_device` cases the SDL driver contradicts, plus `akgl_backends`, `akgl_frontend`, `docs_screenshots` and `akgl_typing` — the last of which is the skip, and the `akgl_build` CI job is where it skips |
 | `docs_examples` | Every fenced block in `README.md`, `MAINTENANCE.md` and `docs/` executed and byte-compared: 71 programs, 9 transcripts, 79 output comparisons, 4 C snippets, 2 excerpts, 2 shell blocks and 19 figures in the default build. The C-snippet count reads 0 when the harness is run by hand without `--cflags-file`; CTest passes it. `MAINTENANCE.md` documents the fence-tag convention |
 | `docs_screenshots` | 19/19 figures re-rendered and byte-identical to the checked-in PNGs. AKGL build only — rendering a picture needs the SDL half |
-| Golden corpus | 41/41 byte-exact from `tests/reference/` — **and 41/41 again through the SDL binary**, which is most of what proves the frontend changes no output |
+| Language corpus | 65/65 paired expectations — **and 65/65 again through the SDL binary**, which is most of what proves the frontend changes no output |
 | ASan + UBSan | 112/112 |
 | Line coverage | 94.1% (7227/7681) — above the 90% gate |
 | Function coverage | 97.9% (474/484) |
@@ -2340,9 +2339,9 @@ Dependency baseline:
 
 | Submodule | Version | Notes |
 |---|---|---|
-| `deps/libakerror` | 2.0.1 | Private ownership-enforced status registry. akbasic reserves 512–767 in `akbasic_error_register()`. Does not namespace its `coverage` target when embedded — worked around in our `CMakeLists.txt`. **2.0.0 is thread safe and an ABI break** (`libakerror.so.2`): `__akerr_last_ignored` is thread-local and `akerr_next_error()` returns an owned reference, neither of which fails to link when mismatched. **2.0.1 fixes an exit status that mattered more to this band than to any other** — see below. |
+| `deps/libakerror` | 2.0.2 | Private ownership-enforced status registry. akbasic reserves 512–767 in `akbasic_error_register()`. **2.0.0 is thread safe and an ABI break** (`libakerror.so.2`): the `IGNORE` context is thread-local and `akerr_next_error()` returns an owned reference, neither of which fails to link when mismatched. **2.0.1 fixes an exit status that mattered more to this band than to any other** — see below. **2.0.2** namespaces its embedded `coverage` target (issue #15 — our `add_custom_target` shadow is deleted), installs `akerrorConfigVersion.cmake` at `SameMajorVersion` (issue #16), fixes the `AKERR_USE_STDLIB=OFF` build, retires `PATH_MAX` for `AKERR_MAX_ERROR_FNAME_LENGTH`, and turns the `IGNORE` slot into a released copy — `__akerr_last_ignored` was an `extern` pointer and is now a per-TU `static akerr_last_ignored`. **That last one costs us 1.35 MiB of thread-local storage**: 38 translation units x 37,296 bytes, measured as the whole TLS segment of `build/basic`, where 2.0.1 produced no TLS segment at all. Filed upstream as libakerror issue #37, along with the 84 `-Wunused-variable` warnings it emits. Its `UPGRADING.md` describes a 2.0.3 that `project()` never stamped — libakerror issue #38, which is why the version above reads 2.0.2. |
-| `deps/libakstdlib` | 0.2.0 | soname `libakstdlib.so.0.2`. `AKSL_VERSION_CHECK()` asserted in `tests/version_check.c`. This release fixed all six confirmed defects the port was working around — see §1.9, where the bans are now lifted. |
+| `deps/libakstdlib` | 0.2.0 | soname `libakstdlib.so.0.2`. `AKSL_VERSION_CHECK()` asserted in `tests/version_check.c`. This release fixed all six confirmed defects the port was working around — see §1.9, where the bans are now lifted. Since then, and with no version bump: **directory wrappers landed** (`aksl_opendir`/`readdir`/`closedir`/`rewinddir`, issue #10) — the gap `DIRECTORY` was refused for, so that refusal now says only that the verb is unwritten; file-metadata wrappers landed; and `aksl_snprintf` keeps its `int *count` but now reports the *required* length on truncation rather than 0. Only read on success here, so nothing moved. |
-| `deps/libakgl` | 0.7.0 | soname `libakgl.so.0.7`. Owns status codes 256–260. Linked and tested under `-DAKBASIC_WITH_AKGL=ON`, which still defaults OFF so the core library and its whole suite build on a machine with no SDL. **0.3.0 closed every API gap this port had filed** — see §7 — so the four workarounds §3 used to list are gone. 0.4.0 was a leak-and-overread release that changed no public struct. **0.5.0 is the first that broke our source as well as our ABI**: it namespaced every exported symbol, so `akgl_render_bind2d` is `akgl_render_2d_bind`, `akgl_sprite_sheet_coords_for_frame` is `akgl_spritesheet_coords_for_frame`, the `renderer`/`camera`/`window` globals carry the prefix, and `_akgl_renderer`/`_akgl_camera` are `akgl_default_renderer`/`akgl_default_camera`. `include/akbasic/akgl.h` asserts the floor. **0.6.0 and 0.7.0 broke nothing here** — 0.6.0 is three arcade-physics fixes and a `physics.max_timestep` property this port does not use, and 0.7.0 reports failures `libakstdlib`'s wrappers were already catching and takes `libakerror` 2.0.1. The floor moved anyway, because deciding for ourselves which of libakgl's minor releases were really compatible is the judgement the soname exists to take away. |
+| `deps/libakgl` | 0.9.0 | soname `libakgl.so.0.9`. Owns status codes 256–262. Linked and tested under `-DAKBASIC_WITH_AKGL=ON`, which still defaults OFF so the core library and its whole suite build on a machine with no SDL. **0.3.0 closed every API gap this port had filed** — see §7 — so the four workarounds §3 used to list are gone. 0.4.0 was a leak-and-overread release that changed no public struct. **0.5.0 is the first that broke our source as well as our ABI**: it namespaced every exported symbol, so `akgl_render_bind2d` is `akgl_render_2d_bind`, `akgl_sprite_sheet_coords_for_frame` is `akgl_spritesheet_coords_for_frame`, the `renderer`/`camera`/`window` globals carry the prefix, and `_akgl_renderer`/`_akgl_camera` are `akgl_default_renderer`/`akgl_default_camera`. `include/akbasic/akgl.h` asserts the floor. **0.6.0 and 0.7.0 broke nothing here** — 0.6.0 is three arcade-physics fixes and a `physics.max_timestep` property this port does not use, and 0.7.0 reports failures `libakstdlib`'s wrappers were already catching and takes `libakerror` 2.0.1. **0.8.0 and 0.9.0 broke nothing here either** — 0.8.0 is the collision subsystem (`AKGL_ERR_COLLISION`, code 261, and the vendored `libccd` and `tg` submodules that come with it), and 0.9.0 is the `akgl_ui` subsystem (`AKGL_ERR_UI`, code 262, and vendored `clay`), which is what `src/ui_akgl.c` draws through. Both widen libakgl's reserved band from five codes to seven; the range map in `MAINTENANCE.md` carries it. The floor moved anyway, because deciding for ourselves which of libakgl's minor releases were really compatible is the judgement the soname exists to take away. **Note `deps/libakgl/deps/` pins its own `libakerror` and `libakstdlib` older than ours**; the top-level build declares both targets first and libakgl's `if(NOT TARGET ...)` guards mean its copies are never configured, so what libakgl actually compiles against is what this tree pins. |
 
 **An unhandled error in this band used to exit zero, and 512 is the worst possible base for
 that.** `libakerror`'s default unhandled-error handler ended in `exit(errctx->status)`, and a
@@ -2553,7 +2552,7 @@ What remains, in priority order:
       this whole arrangement exists against.
 
     The byte comparison is a deliberate bet that the dummy driver and the software renderer
-    are reproducible, which is the same bet `tests/reference/` already makes about golden
+    are reproducible, which is the same bet `tests/language/` makes about golden
     output. Verified run-to-run and build-to-build here; what is untested is an SDL upgrade
     that moves one pixel of a diagonal. **If that happens, regenerate the figures in the same
     commit as the bump** — do not weaken the test to a size check, which would pass for every
@@ -2636,7 +2635,7 @@ reduced against `build/basic`, the stdio build, unless it says otherwise.
 
    **It is narrower than it looks, and the golden corpus is why.** The first attempt
    released the scope on *any* skip, which broke
-   `tests/reference/language/flowcontrol/nestedforloopwaitingforcommand.bas`: a zero-
+   `tests/language/flowcontrol/nestedforloopwaitingforcommand.bas`: a zero-
    iteration `FOR` skips its body by the same mechanism, and there the orphan is
    load-bearing -- it is what absorbs the inner `NEXT` so the outer one still finds its
    `FOR`. Releasing it turns that case into "NEXT outside the context of FOR". So the

docs/09-files-and-disk.md

@@ -126,7 +126,7 @@ exists, and reading into one you never sized writes over something else.
 | `COLLECT` | validates a disk's block allocation map. There is no map |
 | `BACKUP` | duplicates one disk onto another. There are no disks |
 | `BOOT` | loads and runs a boot sector. There is no boot sector |
-| `DIRECTORY` / `CATALOG` | needs a directory-reading wrapper the standard library does not have yet. Filed upstream |
+| `DIRECTORY` / `CATALOG` | not written yet. It was blocked on a directory-reading wrapper in the standard library; that landed, so only the verb is outstanding |
 
 `DCLEAR` is the exception among the drive verbs: resetting a drive also closes its
 channels, and closing the channels is real, so that is what it does.

docs/11-verb-reference.md

@@ -35,7 +35,7 @@ for the reasoning in each case.
 | `DIALOG` | `DIALOG ["text"]` | Show a text panel across the bottom of the screen. No argument takes it down. See Chapter 19. |
 | `DIM` | `DIM A#(n [,...])` | Make an array. Subscripts start at zero; `n` is the count. |
 | `DIM` … `AS` | `DIM S@ AS T`, `DIM P@ AS PTR TO T` | Make a structure, or a strict pointer to one. See Chapter 16. |
-| `DIRECTORY` | `DIRECTORY` | **Refused.** Needs a directory-reading wrapper that does not exist yet. |
+| `DIRECTORY` | `DIRECTORY` | **Refused.** Not written yet; the standard-library wrapper it waited on has landed. |
 | `DLOAD` | `DLOAD "name"` | Load a program from a file. |
 | `DO` | `DO [WHILE c | UNTIL c]` | Start a loop. The condition may be here, on the `LOOP`, or neither. |
 | `DOPEN` | `DOPEN n, "name" [,W]` | Open a file on channel `n`. `W` opens it for writing. |

docs/12-function-reference.md

@@ -9,6 +9,7 @@ so a call with the wrong number is a syntax error rather than a surprise.
 | Function | Args | Form | What it gives |
 |---|---|---|---|
 | `ABS` | 1 | `ABS(n)` | The absolute value of an integer or float. |
+| `ASC` | 1 | `ASC(A$)` | The Unicode code point of a string's first character. |
 | `ATN` | 1 | `ATN(n)` | Arctangent, in radians. |
 | `BUMP` | 1 | `BUMP(1)` | Which sprites have collided, as a bitmask. **Reading clears it.** |
 | `CHR` | 1 | `CHR(n)` | The character for a Unicode code point, as a string. |
@@ -29,6 +30,7 @@ so a call with the wrong number is a syntax error rather than a surprise.
 | `RGR` | 1 | `RGR(f)` | The `GRAPHIC` mode (0), the drawing surface's width (1) or height (2) in pixels, or a character cell's width (3) or height (4). |
 | `RIGHT` | 2 | `RIGHT(A$, n)` | The rightmost `n` characters. Clamped. |
 | `RMENU` | 2 | `RMENU(n, f)` | A menu's state: field 0 the highlighted entry, field 1 whether it has been confirmed. **Reading field 1 clears it.** |
+| `RND` | 1 | `RND(n)` | A random integer from 0 up to but not including `n`. |
 | `RWINDOW` | 1 | `RWINDOW(f)` | The current text window's rows (0) or columns (1). Field 2 is a C128 screen mode and is refused. |
 | `RSPCOLOR` | 1 | `RSPCOLOR(n)` | One of `SPRCOLOR`'s two shared registers, 1 or 2. |
 | `RSPHIT` | 2 | `RSPHIT(n, f)` | One of `SPRHIT`'s settings for sprite `n`, in `SPRHIT`'s own argument order: 0 the kind, 1 to 4 the two corners. |

docs/13-differences.md

@@ -199,7 +199,8 @@ interpreter's error code, which bears no relation to a Commodore error number. P
 - **`BLOAD` requires a length.**
 - **`HEADER`, `COLLECT`, `BACKUP` and `BOOT` are refused.** They operate on a physical
   disk.
-- **`DIRECTORY` is refused** pending a wrapper in the standard library.
+- **`DIRECTORY` is refused** because it is not written yet. The standard-library
+  wrapper it was waiting on has landed, so the remaining work is the verb.
 
 ## Machine
 

docs/14-architecture.md

@@ -743,8 +743,8 @@ way to see that something pushed a scope and never popped it.
 
 ```sh norun
 ctest --test-dir build --output-on-failure -R for_next     # one unit test
-ctest --test-dir build --output-on-failure -R golden_      # the reference corpus
+ctest --test-dir build --output-on-failure -R local_       # the language corpus
-./build/basic tests/reference/language/functions.bas | diff - tests/reference/language/functions.txt
+./build/basic tests/language/functions.bas | diff - tests/language/functions.txt
 ./tests/docs_examples.sh --root . --basic ./build/basic \
     --cflags-file build/docs_cflags.txt docs/14-architecture.md
 ```

docs/17-tutorial-breakout.md

@@ -1005,57 +1005,26 @@ IF NUDGE# = 1 THEN GOSUB UNSTICK
 LABEL UNSTICK
 NUDGE# = 0
 STALL# = 0
-RMAX# = 4
+BVX# = (RND(4) * 3) - 6
-GOSUB RANDOM
-BVX# = (RND# * 3) - 6
 IF BVX# = 0 THEN BVX# = 3
 RETURN
 ```
 
-### You have to write your own random numbers
+### Random numbers are built in
 
-**There is no `RND` in this dialect**, and no `INT`, `SQR`, `ASC` or `TIMER` either. A
+There is no `INT`, `SQR` or `TIMER` in this dialect, but
-linear congruential generator is nine tokens and does the job. Put the number of possible
+`RND(n)` returns an integer from zero through `n - 1`. It seeds itself
-answers in `RMAX#` and read the result from `RND#`:
+from the host clock the first time it is called, so a program only needs the bound:
 
 ```basic
-SEED# = 12345
-RMAX# = 6
-RND# = 0
 I# = 0
 FOR I# = 1 TO 5
-  GOSUB RANDOM
+  PRINT "ROLL " + (RND(6) + 1)
-  PRINT "ROLL " + (RND# + 1)
 NEXT I#
 END
-
-LABEL RANDOM
-SEED# = MOD(((SEED# * 1103515245) + 12345), 2147483648)
-RND# = MOD((SEED# / 65536), RMAX#)
-RETURN
 ```
 
-```output
+Use `RND` for the serve, too, so the ball does not always leave in the same direction:
-ROLL 1
-ROLL 5
-ROLL 2
-ROLL 1
-ROLL 2
-```
-
-The multiplication stays inside a 64-bit integer for any seed below 2147483648, which is
-why the modulus is that number. The answer is taken from the middle bits — `SEED# / 65536`
-— because the low bits of a power-of-two modulus barely change from one call to the next.
-Integer division truncating for free is the `INT` you do not have.
-
-Seed it from the clock at startup. `TI#` is the host's uptime in sixtieths of a second,
-which is different every time the game is run:
-
-```basic norun
-SEED# = TI#
-```
-
-Use `RANDOM` for the serve, too, so the ball does not always leave in the same direction:
 
 ```basic norun
 LABEL SERVE
@@ -1063,16 +1032,43 @@ PX# = (SCW# - PW#) / 2
 HELD# = 1
 BX# = PX# + ((PW# / 2) - 4)
 BY# = PY# - 10
-RMAX# = 2
-GOSUB RANDOM
 BVX# = BSPD#
-IF RND# = 0 THEN BVX# = 0 - BSPD#
+IF RND(2) = 0 THEN BVX# = 0 - BSPD#
 BVY# = 0 - BSPD#
 PDEC# = 0
 GOSUB SHOWSPR
 RETURN
 ```
 
+<details>
+<summary>Historical aside: the LCG this chapter used to teach</summary>
+
+Before `RND` existed, this nine-token linear congruential generator was copied into
+every program. It remains a useful from-scratch PRNG example:
+
+```basic norun
+SEED# = 12345
+RMAX# = 6
+ROLL# = 0
+I# = 0
+FOR I# = 1 TO 5
+  GOSUB RANDOM
+  PRINT "ROLL " + (ROLL# + 1)
+NEXT I#
+END
+
+LABEL RANDOM
+SEED# = MOD(((SEED# * 1103515245) + 12345), 2147483648)
+ROLL# = MOD((SEED# / 65536), RMAX#)
+RETURN
+```
+
+The multiplication stays inside a 64-bit integer for any seed below 2147483648. The
+answer is taken from the middle bits because the low bits of a power-of-two modulus
+barely change from one call to the next. This used to be required; it is now built in.
+
+</details>
+
 `HELD#` is the flag Step 6's loop tests: while it is 1 the ball sits on the paddle, and
 `HOLDBAL` keeps it there:
 
@@ -1422,9 +1418,7 @@ PX# = PX# + D#
 RETURN
 
 LABEL DEMOAIM
-RMAX# = 81
+DOFF# = RND(81) - 40
-GOSUB RANDOM
-DOFF# = RND# - 40
 RETURN
 ```
 
@@ -1501,7 +1495,7 @@ This is the shape of the whole file:
 LABEL SETUP           the geometry from Step 2
                       the declaration block from Step 3
                       the brick faces from Step 5
-                      SEED# = TI#
+                      RND(n) seeds itself from the host clock
                       the ceiling from Step 9
                       GOSUB MKSPR       Step 4
                       GOSUB SNDPROBE    Step 14
@@ -1576,10 +1570,7 @@ BB# = 0
 RX# = 0
 N# = 0
 MROW# = 0
-RMAX# = 2
-RND# = 0
 SND# = 0
-SEED# = 0
 P$ = ""
 H$ = ""
 S$ = ""

docs/18-tutorial-breakout-artwork.md

@@ -1423,7 +1423,8 @@ IF STATE# = 2 THEN GOSUB UNSTICK
 RETURN
 
 LABEL PRESSPAUSE
-IF STATE# = 2 THEN STATE# = 6 : GMTYP# = 0 : BAN$ = "PAUSED" : GOSUB SETBANNER : RETURN
+IF STATE# = 2 THEN STATE# = 6 : GMTYP# = 0 : BAN$ = "PAUSED"
+IF STATE# = 2 THEN BAN$ = "PAUSED" : GOSUB SETBANNER : RETURN
 IF STATE# = 6 THEN STATE# = 2 : BAN$ = "" : GOSUB SETBANNER
 RETURN
 ```

docs/21-tutorial-galaga-enemies.md

@@ -20,7 +20,7 @@ whole development loop; the engine never rebuilds.
 - **[Step 2](#step-2-bind-the-engines-own-actor)** — bind the engine's own
   actor as the second type, which is the point of the whole exercise
 - **[Step 3](#step-3-share-the-frame-and-the-dice)** — share the frame state,
-  and give the script randomness it cannot make itself
+  and hand the script dice the engine controls
 - **[Step 4](#step-4-why-bindings-and-not-arguments)** — see why the structures
   are bindings rather than function arguments
 - **[Step 5](#step-5-the-shape-of-the-script)** — learn the three language
@@ -75,7 +75,7 @@ typedef struct galaga_Enemy
     float    t;		/* parametric clock for the current maneuver	*/
     int32_t  hp;
     int32_t  fire;	/* outbox: script sets 1, engine consumes	*/
-    float    rnd;	/* inbox: engine writes fresh 0..1 each call	*/
+    float    rnd;	/* inbox: fresh 0..1 each call; ROLL% in BASIC	*/
 } galaga_Enemy;
 ```
 
@@ -107,7 +107,7 @@ static const akbasic_HostField ENEMY_FIELDS[] = {
     AKBASIC_HOST_FIELD( galaga_Enemy, t,      "T%",       AKBASIC_HOSTFIELD_FLOAT ),
     AKBASIC_HOST_FIELD( galaga_Enemy, hp,     "HP#",      AKBASIC_HOSTFIELD_INT32 ),
     AKBASIC_HOST_FIELD( galaga_Enemy, fire,   "FIRE#",    AKBASIC_HOSTFIELD_INT32 ),
-    AKBASIC_HOST_FIELD( galaga_Enemy, rnd,    "RND%",     AKBASIC_HOSTFIELD_FLOAT )
+    AKBASIC_HOST_FIELD( galaga_Enemy, rnd,    "ROLL%",    AKBASIC_HOSTFIELD_FLOAT )
 };
 static const akbasic_HostType ENEMY_TYPE = {
     "ENEMY", sizeof(galaga_Enemy), ENEMY_FIELDS, 8
@@ -194,7 +194,7 @@ typedef struct galaga_Shared
     float    playerx;	/* the player actor's position, this frame	*/
     float    playery;
     int32_t  wave;
-    float    rnd;	/* fresh 0..1 each frame; the issue #16 route	*/
+    float    rnd;	/* fresh 0..1 each frame; ROLL% to the script	*/
 } galaga_Shared;
 ```
 
@@ -203,13 +203,24 @@ the engine refreshes it at the top of every frame. The boss reads
 `GAME@.PLAYERX%` to lead its dive; the fire decision reads it to know whether
 anything is worth shooting at.
 
-The `rnd` fields — one here per frame, one on each enemy per call — exist
+The `rnd` fields — one here per frame, one on each enemy per call — carry the
-because the engine's PRNG is the script's **only** source of randomness: write
+engine's PRNG into the script: write `SELF@.ROLL% < DT% * 1.5` and an enemy's
-`SELF@.RND% < DT% * 1.5` and an enemy's trigger finger is a dice roll. There
+trigger finger is a dice roll.
-is no `RND` verb in this dialect; issue #16 tracks adding one, and Chapter
+
-17's breakout hand-rolls a linear congruential generator in BASIC as the other
+The dialect does now have a native `RND` function — issue #16 closed, and
-route. Here the engine fills the field, which also keeps a headless run the
+[Chapter 12](12-function-reference.md) documents it — so this is no longer the
-same game on every machine — the PRNG is the example's own, not libc's.
+*only* route; Chapter 17's breakout hand-rolls a linear congruential generator
+in BASIC as a third. The engine keeps filling the field here on purpose,
+because it buys something `RND` cannot: the numbers come from the example's own
+PRNG rather than libc's, so a headless run is the same game on every machine,
+which is what makes `example_galaga` a test and not just a demo.
+
+**The BASIC name is `ROLL%`, not `RND%`.** A host field is a bare word and
+shares a namespace with every verb and function, so once `RND` became a
+function name a field could no longer be called that — the scanner refuses it
+with *"Reserved word in variable name"*. The C member stays `rnd`; only the
+name the script sees had to move. [Chapter 16](16-structures.md) has the same
+rule for `TYPE` declarations.
 
 ## Step 4: Why bindings, and not arguments
 
@@ -351,7 +362,7 @@ DEF DECIDEFIRE(DT%)
   DX% = GAME@.PLAYERX% - ACTOR@.X%
   IF ABS(DX%) > 140 THEN RETURN 0
   IF ACTOR@.Y% > GAME@.PLAYERY% THEN RETURN 0
-  IF SELF@.RND% < DT% * 1.5 THEN SELF@.FIRE# = 1
+  IF SELF@.ROLL% < DT% * 1.5 THEN SELF@.FIRE# = 1
   RETURN 0
 END
 ```
@@ -386,7 +397,7 @@ DEF UPDATEBEE(DT%)
   IF (S# AND 2) > 0 THEN BEGIN
     ACTOR@.X% = SELF@.HOMEX% + SIN(SELF@.T% * 1.7) * 16
     ACTOR@.Y% = SELF@.HOMEY%
-    IF SELF@.RND% < DT% * 0.04 THEN SELF@.STATE# = 4 : SELF@.T% = 0
+    IF SELF@.ROLL% < DT% * 0.04 THEN SELF@.STATE# = 4 : SELF@.T% = 0
   BEND
   IF (S# AND 4) > 0 THEN BEGIN
     R# = DIVESTEP(DT%, 130, 0.2)

examples/breakout/characters/breakout.bas

@@ -145,7 +145,7 @@ RX# = 0
 N# = 0
 MROW# = 0
 RMAX# = 2
-RND# = 0
+ROLL# = 0
 SND# = 0
 P$ = ""
 H$ = ""
@@ -172,7 +172,8 @@ BSG$(4) = "[--]"
 BSG$(5) = "[--]"
 
 REM --- the seed -------------------------------------------------------
-REM There is no RND in this dialect. TI# is jiffies off the host's clock
+REM RND exists now, but this program keeps its own LCG so a headless run
+REM is the same game every time. TI# is jiffies off the host's clock
 REM and is host uptime rather than zero-based, which makes it a fine seed.
 SEED# = TI#
 
@@ -389,17 +390,18 @@ BY# = PY# - 10
 RMAX# = 2
 GOSUB RANDOM
 BVX# = BSPD#
-IF RND# = 0 THEN BVX# = 0 - BSPD#
+IF ROLL# = 0 THEN BVX# = 0 - BSPD#
 BVY# = 0 - BSPD#
 PDEC# = 0
 GOSUB SHOWSPR
 RETURN
 
-REM A linear congruential generator, because this dialect has no RND.
+REM A linear congruential generator. RND(n) would do this in one token
+REM now; the LCG stays because its sequence is reproducible.
 REM The multiply stays inside int64 for any seed under 2^31.
 LABEL RANDOM
 SEED# = MOD(((SEED# * 1103515245) + 12345), 2147483648)
-RND# = MOD((SEED# / 65536), RMAX#)
+ROLL# = MOD((SEED# / 65536), RMAX#)
 RETURN
 
 REM ####################################################################
@@ -632,7 +634,7 @@ NUDGE# = 0
 STALL# = 0
 RMAX# = 4
 GOSUB RANDOM
-BVX# = (RND# * 3) - 6
+BVX# = (ROLL# * 3) - 6
 IF BVX# = 0 THEN BVX# = 3
 RETURN
 
@@ -641,7 +643,7 @@ REM like something with a hand on the paddle rather than a mirror.
 LABEL DEMOAIM
 RMAX# = 81
 GOSUB RANDOM
-DOFF# = RND# - 40
+DOFF# = ROLL# - 40
 RETURN
 
 REM ####################################################################

examples/breakout/sprites/breakout.bas

@@ -241,7 +241,8 @@ SLX# = 0
 SLY# = 0
 SLI# = 0
 REM The two eraser stamps. Declared here for exactly the same reason -- built
-REM inside DRAWPROTOS and left undeclared, they were SHAPE:6 and SHAPE:7 inside
+REM inside DRAWPROTOS and left undeclared, they were SHAPE:6 and SHAPE:7
+REM inside
 REM it and empty everywhere else.
 BL$ = ""
 HBL$ = ""
@@ -254,10 +255,13 @@ REM cursor through every DATA item in the program in the order they appear
 REM in the file, so whichever loader runs first gets the DATA that is
 REM written first. The tables are written first.
 REM The text layer repaints every row it owns, opaque, so it has to be moved
-REM out of the way before anything drawn can be seen. Two rows at the bottom is
+REM out of the way before anything drawn can be seen. Two rows at the bottom
+REM is
 REM enough for the final score, and hands the other thirty-five to the drawing
-REM verbs. Everything this game draws then simply stays there -- a drawing goes
+REM verbs. Everything this game draws then simply stays there -- a drawing
-REM into a layer the frame composites, so nothing here is captured into a sprite
+REM goes
+REM into a layer the frame composites, so nothing here is captured into a
+REM sprite
 REM and nothing is redrawn every frame.
 WINDOW 0, 35, 49, 36
 
@@ -293,7 +297,8 @@ ENVELOPE 0, 0, 6, 0, 4
 TEMPO 12
 
 COLLISION 2, BRICKHIT
-REM The stamps, once. They used to be rebuilt whenever the SSHAPE pool ran dry,
+REM The stamps, once. They used to be rebuilt whenever the SSHAPE pool ran
+REM dry,
 REM because every frame's capture spent another slot; nothing captures now, so
 REM eight slots are spent here and never again.
 GOSUB DRAWPROTOS
@@ -374,7 +379,8 @@ COLOR 1, 1
 FOR K# = 0 TO 15
   DRAW 1, 0, 130 + K# TO 67, 130 + K#
 NEXT K#
-REM And an eighth the width of the HUD strip, for the same reason: the strip is
+REM And an eighth the width of the HUD strip, for the same reason: the strip
+REM is
 REM rewritten whenever a number in it changes, and the old digits have to go
 REM somewhere first.
 FOR K# = 0 TO 59
@@ -393,7 +399,8 @@ DPLAY# = 1
 DHUD# = 1
 RETURN
 
-REM Take one brick off the screen: stamp the blank over it. Called when a brick
+REM Take one brick off the screen: stamp the blank over it. Called when a
+REM brick
 REM breaks, so the field is never redrawn as a whole during play -- which is
 REM what lets the whole live-list machinery go.
 LABEL ERASEBRICK
@@ -444,7 +451,8 @@ WIDTH 1
 COLOR 0, 1 : COLOR 1, 4 : COLOR 2, 8 : COLOR 3, 5
 COLOR 4, 11 : COLOR 5, 16 : COLOR 6, 6
 REM The old strip goes first. Nothing here clears the screen -- a drawing
-REM stays, which is the whole point -- so the digits that were there have to be
+REM stays, which is the whole point -- so the digits that were there have to
+REM be
 REM stamped over before the new ones are drawn.
 Z$ = HBL$
 GSHAPE Z$, 0, 0
@@ -495,7 +503,10 @@ IF SNDON# = 0 THEN VOL 0
 RETURN
 
 LABEL PRESSPAUSE
-IF STATE# = 2 THEN STATE# = 6 : GMTYP# = 0 : BAN$ = "PAUSED" : GOSUB SETBANNER : RETURN
+IF STATE# <> 2 THEN GOTO PRESSPAUSE2
+STATE# = 6 : GMTYP# = 0 : BAN$ = "PAUSED" : GOSUB SETBANNER
+RETURN
+LABEL PRESSPAUSE2
 IF STATE# = 6 THEN STATE# = 2 : BAN$ = "" : GOSUB SETBANNER
 RETURN
 

examples/galaga/enemies.c

@@ -71,10 +71,15 @@ static char *ENEMY_CHARACTER[GALAGA_ENEMY_KINDS] = {
 /* --------------------------------------------------------------- random --- */
 
 /*
- * No RND verb exists (issue #16), so the engine is the script's only source
+ * The engine is this script's source of randomness: it refreshes GAME@.ROLL%
- * of randomness: it refreshes GAME@.RND% each frame and SELF@.RND% each call
+ * each frame and SELF@.ROLL% each call from this PRNG. A hand-rolled LCG
- * from this PRNG. A hand-rolled LCG rather than rand() so a headless run is
+ * rather than rand() so a headless run is the same game on every libc, which
- * the same game on every libc.
+ * is what lets interop_test.c assert exact counts. The dialect gained a native
+ * RND (issue #16) after this example was written; the field stays because RND
+ * would reintroduce exactly the per-machine variation this avoids.
+ *
+ * The BASIC-visible name is ROLL%, not RND%: host field names share a
+ * namespace with verbs and functions, so RND stopped being available as one.
  */
 static uint32_t PRNG_STATE = 0x12345678u;
 

examples/galaga/galaga.bas

@@ -50,7 +50,7 @@ DEF DECIDEFIRE(DT%)
   DX% = GAME@.PLAYERX% - ACTOR@.X%
   IF ABS(DX%) > 140 THEN RETURN 0
   IF ACTOR@.Y% > GAME@.PLAYERY% THEN RETURN 0
-  IF SELF@.RND% < DT% * 1.5 THEN SELF@.FIRE# = 1
+  IF SELF@.ROLL% < DT% * 1.5 THEN SELF@.FIRE# = 1
   RETURN 0
 
 REM Bee: enter, breathe in formation, occasionally dive nearly straight.
@@ -65,7 +65,7 @@ DEF UPDATEBEE(DT%)
   IF (S# AND 2) > 0 THEN BEGIN
     ACTOR@.X% = SELF@.HOMEX% + SIN(SELF@.T% * 1.7) * 16
     ACTOR@.Y% = SELF@.HOMEY%
-    IF SELF@.RND% < DT% * 0.04 THEN SELF@.STATE# = 4 : SELF@.T% = 0
+    IF SELF@.ROLL% < DT% * 0.04 THEN SELF@.STATE# = 4 : SELF@.T% = 0
   BEND
   IF (S# AND 4) > 0 THEN BEGIN
     R# = DIVESTEP(DT%, 130, 0.2)
@@ -85,7 +85,7 @@ DEF UPDATEBFLY(DT%)
   IF (S# AND 2) > 0 THEN BEGIN
     ACTOR@.X% = SELF@.HOMEX% + SIN(SELF@.T% * 2.1) * 24
     ACTOR@.Y% = SELF@.HOMEY%
-    IF SELF@.RND% < DT% * 0.05 THEN SELF@.STATE# = 4 : SELF@.T% = 0
+    IF SELF@.ROLL% < DT% * 0.05 THEN SELF@.STATE# = 4 : SELF@.T% = 0
   BEND
   IF (S# AND 4) > 0 THEN BEGIN
     R# = DIVESTEP(DT%, 260, 0.1)
@@ -108,7 +108,7 @@ DEF UPDATEBOSS(DT%)
   IF (S# AND 2) > 0 THEN BEGIN
     ACTOR@.X% = SELF@.HOMEX% + SIN(SELF@.T% * 1.1) * 10
     ACTOR@.Y% = SELF@.HOMEY%
-    IF SELF@.RND% < DT% * 0.03 THEN SELF@.STATE# = 4 : SELF@.T% = 0
+    IF SELF@.ROLL% < DT% * 0.03 THEN SELF@.STATE# = 4 : SELF@.T% = 0
   BEND
   IF (S# AND 4) > 0 THEN BEGIN
     R# = DIVESTEP(DT%, 60, 0.9)

examples/galaga/galaga.h

@@ -77,7 +77,7 @@ typedef struct galaga_Enemy
     float    t;		/* parametric clock for the current maneuver	*/
     int32_t  hp;
     int32_t  fire;	/* outbox: script sets 1, engine consumes	*/
-    float    rnd;	/* inbox: engine writes fresh 0..1 each call	*/
+    float    rnd;	/* inbox: fresh 0..1 each call; ROLL% in BASIC	*/
 } galaga_Enemy;
 
 /** @brief Frame state every enemy may read. Bound once as GAME@. */
@@ -86,7 +86,7 @@ typedef struct galaga_Shared
     float    playerx;	/* the player actor's position, this frame	*/
     float    playery;
     int32_t  wave;
-    float    rnd;	/* fresh 0..1 each frame; the issue #16 route	*/
+    float    rnd;	/* fresh 0..1 each frame; ROLL% to the script	*/
 } galaga_Shared;
 
 /* --------------------------------------------------------------- screens --- */

examples/galaga/main.c

@@ -491,7 +491,8 @@ static akerr_ErrorContext *frame(bool *running)
     }
 
     /* The shared frame state, refreshed before any enemy thinks. The engine
-     * filling GAME@.RND% is the issue #16 route: no RND verb exists. */
+     * fills GAME@.ROLL% from its own PRNG rather than letting the script call
+     * the native RND, so a headless run is the same game on every machine. */
     galaga_shared.playerx = galaga_game.player->x + 50.0f;
     galaga_shared.playery = galaga_game.player->y;
     galaga_shared.rnd = galaga_random();

examples/galaga/script.c

@@ -62,7 +62,7 @@ static const akbasic_HostField ENEMY_FIELDS[] = {
     AKBASIC_HOST_FIELD( galaga_Enemy, t,      "T%",       AKBASIC_HOSTFIELD_FLOAT ),
     AKBASIC_HOST_FIELD( galaga_Enemy, hp,     "HP#",      AKBASIC_HOSTFIELD_INT32 ),
     AKBASIC_HOST_FIELD( galaga_Enemy, fire,   "FIRE#",    AKBASIC_HOSTFIELD_INT32 ),
-    AKBASIC_HOST_FIELD( galaga_Enemy, rnd,    "RND%",     AKBASIC_HOSTFIELD_FLOAT )
+    AKBASIC_HOST_FIELD( galaga_Enemy, rnd,    "ROLL%",    AKBASIC_HOSTFIELD_FLOAT )
 };
 static const akbasic_HostType ENEMY_TYPE = {
     "ENEMY", sizeof(galaga_Enemy), ENEMY_FIELDS, 8
@@ -87,7 +87,7 @@ static const akbasic_HostField GAME_FIELDS[] = {
     AKBASIC_HOST_FIELD( galaga_Shared, playerx, "PLAYERX%", AKBASIC_HOSTFIELD_FLOAT ),
     AKBASIC_HOST_FIELD( galaga_Shared, playery, "PLAYERY%", AKBASIC_HOSTFIELD_FLOAT ),
     AKBASIC_HOST_FIELD( galaga_Shared, wave,    "WAVE#",    AKBASIC_HOSTFIELD_INT32 ),
-    AKBASIC_HOST_FIELD( galaga_Shared, rnd,     "RND%",     AKBASIC_HOSTFIELD_FLOAT )
+    AKBASIC_HOST_FIELD( galaga_Shared, rnd,     "ROLL%",    AKBASIC_HOSTFIELD_FLOAT )
 };
 static const akbasic_HostType GAME_TYPE = {
     "GAME", sizeof(galaga_Shared), GAME_FIELDS, 4

examples/megademo/README.md

@@ -56,7 +56,10 @@ This is a tour of the interpreter's edges, on purpose:
   counterpoint: a genuine 24x21 `SPRSAV` type-in sprite, 63 bytes, which is
   everything `DATA` has room to say. The paint is the reveal, and the exit is a
   stride-63 column dissolve — 63 is coprime to 160, so the walk hits every
-  column once and looks random while carrying no state.
+  column once and looks random while carrying no state. The strings come in
+  64-character chunks because a source line is 80 columns, like the machines
+  this pretends to be — the decoder carries its cursor from one `IM$` entry to
+  the next, and the generator refuses to cut inside a run.
 - **And then the picture is video.** Six delta frames loop the floor grid toward
   you and crawl the sun's slice pattern — full motion video, 1.3 KB total, about
   220 bytes a frame. A delta re-encodes only the rows that changed: an `R`
@@ -82,6 +85,10 @@ This is a tour of the interpreter's edges, on purpose:
   batch a bar of noise drums. Noise is real: `ENVELOPE`'s sixth argument is a
   waveform, 0 to 3, which Chapter 7 forgot to mention. Voice 1 carries the tune so
   the collision blips (voice 2) and scene sweeps (voice 3) never steal its channel.
+  A batch is four `PLAY` statements, one bar each — the 80-column line limit will
+  not hold four bars in one string, and it does not need to: the parser's voice,
+  envelope and duration state persists across statements and every `PLAY` appends
+  to the same queue, so four bars queue exactly as one line would.
 
 It also probes for its hardware like a proper boot loader, with one `TRAP` per
 device: no graphics refuses by name and exits, no audio mutes the soundtrack, no

examples/megademo/megademo.bas

@@ -10,7 +10,7 @@ REM  A demoscene production for the akbasic interpreter, written as if
 REM  it were 1985 and this dialect were the machine under the tree.
 REM  It leans on every corner of the interpreter on purpose:
 REM
-REM    - there is no RND, so it carries chapter 17's LCG and seeds it
+REM    - it carries chapter 17's LCG rather than the native RND, and seeds it
 REM      from the jiffy clock
 REM    - the palette cannot be rewritten, so every "colour cycle" is an
 REM      honest redraw of the same strokes in the next colour
@@ -81,7 +81,7 @@ REM  machine and a predeclared scratch variable occupies one forever,
 REM  where a scoped one gives its slot back. The first cut of this
 REM  program predeclared everything and ran the pool dry.
 RMAX# = 0
-RND# = 0
+ROLL# = 0
 TX% = 0
 TB# = 0
 
@@ -461,38 +461,78 @@ BS% = W# / 160
 IF BS% < 1 THEN BS% = 1
 REM  ---- PICTURE-BEGIN (generated by vaporwave.py; do not
 REM  ---- hand-edit -- rerun the script to change the picture)
-DIM IM$(16)
+DIM IM$(56)
 DIM VA#(6)
 DIM VB#(6)
-NS# = 9
+NS# = 32
-VA#(0) = 9
+VA#(0) = 32
-VB#(0) = 9
+VB#(0) = 35
-VA#(1) = 10
+VA#(1) = 36
-VB#(1) = 10
+VB#(1) = 39
-VA#(2) = 11
+VA#(2) = 40
-VB#(2) = 12
+VB#(2) = 43
-VA#(3) = 13
+VA#(3) = 44
-VB#(3) = 13
+VB#(3) = 47
-VA#(4) = 14
+VA#(4) = 48
-VB#(4) = 14
+VB#(4) = 51
-VA#(5) = 15
+VA#(5) = 52
-VB#(5) = 15
+VB#(5) = 55
-IM$(0) = "G9G9G9G9GPGHEHG9GTEHG9GTEHGPGPEHG9GTEHG9GTEHGHGXEHGTBAG8EHG9GTEHG5EHGPEHG5EHGPEHG5EHGAPAG3EHGPEHG5EHGPEHGXGHEHG5EHGPEHG5EHGFBAGIEHGPGPEHGPEHGHEHGPEHGPEHGHEHGPEHGHEHGPEHGPEHGHEHGBPAGMEHGPEHGHEHGPEHGHEHGPEHGPEHGHEHGPEHGPEHGHEHGPEHGHEPGHEHGPEH"
+IM$(0) = "G9G9G9G9GPGHEHG9GTEHG9GTEHGPGPEHG9GTEHG9GTEHGHGXEHGTBAG8EHG9GTEH"
-IM$(1) = "GHEPGHEHGPEHGHEPGHEHGHEGBAEHGHEHGPEHGHEPGHEHGPEHGHEHGPEHGHEPGHEHGPEHGHEPGHEHGPECPAEDGHEPGHEHGHEPGHEPGHEHGHEPGHEPGHEHGHEPGHEHGHEPGHEPGHECBAEDGHEPGHEPGHEHGHEPGHEHGHEPGHEPGHEHGHEPGHEPEPGHEPGHE5GHEPGHE5GHEHEXGHEPGHEEPAEZGHEPGHE5GHE5GHEPGHE5GHEP"
+IM$(1) = "G5EHGPEHG5EHGPEHG5EHGAPAG3EHGPEHG5EHGPEHGXGHEHG5EHGPEHG5EHGFBAGI"
-IM$(2) = "GHE5GHE9ETGHE9ETGHEXEHGHE9ETGHHAE9ESGHEPEPGBBAGEE9EMHOE9ETGHEHE9E7HUE9E6E9E4H0E9E3E9E3H2E9EHBAETEHKHE9ELH6E9ECKHEPEPKHE9EBH9HAE9EIKHEHEXKHE2H9HCE9EPKHE5KHEPKDH9HEKCEPKHE5KHE5KHEKH9HGEBKHEPKHEXEHKHE5KHEBH9HIEIKHEPKHEPEPKHEPKHEHKAH9HKKHEHKHEP"
+IM$(2) = "EHGPGPEHGPEHGHEHGPEHGPEHGHEHGPEHGHEHGPEHGPEHGHEHGBPAGMEHGPEHGHEH"
-IM$(3) = "KHEHKHEPKHEPKHH9HMEGKHEHKHEPKHEHKHEPKHEPH9HMEOKHEHKHEPKHEHKPEHKHEGH9HOKFEPKHEHKPEHKHEHKPEHKGH9HOEFKHEPKHEHKHEPKHEHKPEFH9HQKEEHKHEPKHEHKHEPKHEHKMH9HSKLEHKHEPKHEHKPEHKHEHKEH9HSEDKPEHKPEHKHEHKPEHKHEEH9HSKDEHKPEHKPKPEHKPEHKDH9HUECKHEHKPEHKHKXEH"
+IM$(3) = "GPEHGHEHGPEHGPEHGHEHGPEHGPEHGHEHGPEHGHEPGHEHGPEHGHEPGHEHGPEHGHEP"
-IM$(4) = "KPEDH9HUKCEHK5EHK5EHKLH9HUKKEHK5EHK5EHKCH9HWEBKPEHKXKHEHK8I9IWKZEHKPKPEHK0I9IWK7EHKHKXEHKSI9IWK9KFEHK9KOI9IWK9KNK9KOI9IWK9KNK9KOI9IWK9KNKPIHKZI9IYK6IHKHKXIHKSI9IWK9KFIHK5IHKKI9IWK9KNIHK5IHKCI9IYKPIHKXKHIHK5IHKPIHK5IHKPIHKPKPIHK0I9IWKJIHKPIH"
+IM$(4) = "GHEHGHEGBAEHGHEHGPEHGHEPGHEHGPEHGHEHGPEHGHEPGHEHGPEHGHEPGHEHGPEC"
-IM$(5) = "KHIHKPIHKPI9IZKBIHKHIHKPIHKHIHKPIHKKI9IWKJIHKHIHKPIHKHIHKPIHKDI9IXKPIHKHIHKHKHIHKHIPKHI9IYKCIHKPIHKHIHKPIHKHIPKHIHKPIHKHIPKHIHKPIHKHIHKPIHKHI9I9IHKHIHKPIHKHIPKHIHKHIEC9CSKDIPKHIPKHIHKHIPKHIHKEC9CSIDKHIPKHIPIPKHIPKHIFC9CQKEIHKHIPKHIHIXKHIPKG"
+IM$(5) = "PAEDGHEPGHEHGHEPGHEPGHEHGHEPGHEPGHEHGHEPGHEHGHEPGHEPGHECBAEDGHEP"
-IM$(6) = "C9COIFKHI5KHI5KHIPKHI5KHIPKHI5KHI5KHIPKHI5KHIPKHIXIHKHI9IDC9CMI4KHIPIPKHI6C9CKI9IDKHIHIXKHIZC9CII9IMKHI9IWC9CGI9IVI9I9I9I9IPI9I9I9I9IPQ9Q9Q9Q9QPE9E9E9E9EPE9E9E9E9EPQ9Q9Q9Q9QPE9E9E9E9EPQ9Q9Q9Q9QPE9E9E9E9EPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9"
+IM$(6) = "GHEPGHEHGHEPGHEHGHEPGHEPGHEHGHEPGHEPEPGHEPGHE5GHEPGHE5GHEHEXGHEP"
-IM$(7) = "Q9QPE9E9E9E9EPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPE9E9E9E9EPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPE9E9E9E9EPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9"
+IM$(7) = "GHEEPAEZGHEPGHE5GHE5GHEPGHE5GHEPGHE5GHE9ETGHE9ETGHEXEHGHE9ETGHHA"
-IM$(8) = "Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QP"
+IM$(8) = "E9ESGHEPEPGBBAGEE9EMHOE9ETGHEHE9E7HUE9E6E9E4H0E9E3E9E3H2E9EHBAET"
-IM$(9) = "RBRQ9QOKMQHK5RBSQ9QTI9IRRBXQ9QTKPQHKHQPKERBYQ9QPI9IHRB3Q9QSKAI5KHIJRB5Q9QTC9CMRB9Q9QWI9IGRCBQ9QYC9CCRCIA9A9A9A9APRCJE9E9E9E9EPRCNA9A9A9A9APRCOE9E9E9E9EPRCUA9A9A9A9APRCVE9E9E9E9EPRC5A9A9A9A9APRC7E9E9E9E9EP"
+IM$(9) = "EHKHE9ELH6E9ECKHEPEPKHE9EBH9HAE9EIKHEHEXKHE2H9HCE9EPKHE5KHEPKDH9"
-IM$(10) = "RBQQ9QOK9KIQHKFRBRQ9QOI9IQRBWQ9QPKLQHKHQHKPRBXQ9QTI9QLIERB2Q9QRIBKHIPKHIPKCRB4Q9QSC9CORB8Q9QVI3KHIGRCAQ9QXC9CERCJA9A9A9A9APRCKE9E9E9E9EPRCOA9A9A9A9APRCPE9E9E9E9EPRCVA9A9A9A9APRCXE9E9E9E9EPRC7A9A9A9A9APRDAE9E9E9E9EP"
+IM$(10) = "HEKCEPKHE5KHE5KHEKH9HGEBKHEPKHEXEHKHE5KHEBH9HIEIKHEPKHEPEPKHEPKH"
-IM$(11) = "RBPQ9QOK9KAQHKNRBQQ9QOI9IWRBVQ9QOKEQHKHQHKPQHKFRBWQ9QPI9IPRB1Q9QQKCIPKHIPKHIDRB3Q9QSC9CORB7Q9QUIWKHIPRB9Q9QWC9CGRCEA9A9A9A9APRCFE9E9E9E9EPRCGA9A9A9A9APRCHE9E9E9E9EPRCPA9A9A9A9APRCQE9E9E9E9EPRCXA9A9A9A9APRCZE9E9E9E9EPRDAA9A9A9A9APRDCE9E9E9E9"
+IM$(11) = "EHKAH9HKKHEHKHEPKHEHKHEPKHEPKHH9HMEGKHEHKHEPKHEHKHEPKHEPH9HMEOKH"
-IM$(12) = "EP"
+IM$(12) = "EHKHEPKHEHKPEHKHEGH9HOKFEPKHEHKPEHKHEHKPEHKGH9HOEFKHEPKHEHKHEPKH"
-IM$(13) = "RBOQ9QNK3QHKWRBPQ9QOI9IWRBUQ9QTKHQHKPQHKNRBVQ9QOI9IWRB0Q9QQIKKHIPKHIHKDRB1Q9QQC9CSRB2Q9QRC9CQRB6Q9QTIPKHIYRB8Q9QVC9CIRCKA9A9A9A9APRCLE9E9E9E9EPRCQA9A9A9A9APRCRE9E9E9E9EPRCZA9A9A9A9APRC1E9E9E9E9EPRDCA9A9A9A9APRDFE9E9E9E9EP"
+IM$(13) = "EHKPEFH9HQKEEHKHEPKHEHKHEPKHEHKMH9HSKLEHKHEPKHEHKPEHKHEHKEH9HSED"
-IM$(14) = "RBOQ9QNI9IYRBTQ9QOKEQHKPQHKVRBUQ9QTI9IRRBZQ9QTKHQHKPQHKHRB0Q9QQC9CSRB5Q9QTIHKHI5KARB7Q9QUC9CKRCBQ9QYI9ICRCHA9A9A9A9APRCIE9E9E9E9EPRCLA9A9A9A9APRCME9E9E9E9EPRCRA9A9A9A9APRCTE9E9E9E9EPRC1A9A9A9A9APRC3E9E9E9E9EPRDFA9A9A9A9APRDIE9E9E9E9EP"
+IM$(14) = "KPEHKPEHKHEHKPEHKHEEH9HSKDEHKPEHKPKPEHKPEHKDH9HUECKHEHKPEHKHKXEH"
-IM$(15) = "RBSQ9QTKPQHK3RBTQ9QOI9IWRBYQ9QPKDQHKPQHKHRBZQ9QTI9ILRB4Q9QSIAKHI5KHIBRB6Q9QTC9CMRCAQ9QXI9IERCEE9E9E9E9EPRCFA9A9A9A9APRCGE9E9E9E9EPRCMA9A9A9A9APRCNE9E9E9E9EPRCTA9A9A9A9APRCUE9E9E9E9EPRC3A9A9A9A9APRC5E9E9E9E9EPRDIA9A9A9A9AP"
+IM$(15) = "KPEDH9HUKCEHK5EHK5EHKLH9HUKKEHK5EHK5EHKCH9HWEBKPEHKXKHEHK8I9IWKZ"
+IM$(16) = "EHKPKPEHK0I9IWK7EHKHKXEHKSI9IWK9KFEHK9KOI9IWK9KNK9KOI9IWK9KNK9KO"
+IM$(17) = "I9IWK9KNKPIHKZI9IYK6IHKHKXIHKSI9IWK9KFIHK5IHKKI9IWK9KNIHK5IHKCI9"
+IM$(18) = "IYKPIHKXKHIHK5IHKPIHK5IHKPIHKPKPIHK0I9IWKJIHKPIHKHIHKPIHKPI9IZKB"
+IM$(19) = "IHKHIHKPIHKHIHKPIHKKI9IWKJIHKHIHKPIHKHIHKPIHKDI9IXKPIHKHIHKHKHIH"
+IM$(20) = "KHIPKHI9IYKCIHKPIHKHIHKPIHKHIPKHIHKPIHKHIPKHIHKPIHKHIHKPIHKHI9I9"
+IM$(21) = "IHKHIHKPIHKHIPKHIHKHIEC9CSKDIPKHIPKHIHKHIPKHIHKEC9CSIDKHIPKHIPIP"
+IM$(22) = "KHIPKHIFC9CQKEIHKHIPKHIHIXKHIPKGC9COIFKHI5KHI5KHIPKHI5KHIPKHI5KH"
+IM$(23) = "I5KHIPKHI5KHIPKHIXIHKHI9IDC9CMI4KHIPIPKHI6C9CKI9IDKHIHIXKHIZC9CI"
+IM$(24) = "I9IMKHI9IWC9CGI9IVI9I9I9I9IPI9I9I9I9IPQ9Q9Q9Q9QPE9E9E9E9EPE9E9E9"
+IM$(25) = "E9EPQ9Q9Q9Q9QPE9E9E9E9EPQ9Q9Q9Q9QPE9E9E9E9EPQ9Q9Q9Q9QPQ9Q9Q9Q9QP"
+IM$(26) = "Q9Q9Q9Q9QPQ9Q9Q9Q9QPE9E9E9E9EPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9"
+IM$(27) = "Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPE9E9E9E9EPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9"
+IM$(28) = "QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9"
+IM$(29) = "Q9Q9Q9QPE9E9E9E9EPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9"
+IM$(30) = "Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QP"
+IM$(31) = "Q9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QPQ9Q9Q9Q9QP"
+IM$(32) = "RBRQ9QOKMQHK5RBSQ9QTI9IRRBXQ9QTKPQHKHQPKERBYQ9QPI9IHRB3Q9QSKAI5"
+IM$(33) = "KHIJRB5Q9QTC9CMRB9Q9QWI9IGRCBQ9QYC9CCRCIA9A9A9A9APRCJE9E9E9E9EP"
+IM$(34) = "RCNA9A9A9A9APRCOE9E9E9E9EPRCUA9A9A9A9APRCVE9E9E9E9EPRC5A9A9A9A9"
+IM$(35) = "APRC7E9E9E9E9EP"
+IM$(36) = "RBQQ9QOK9KIQHKFRBRQ9QOI9IQRBWQ9QPKLQHKHQHKPRBXQ9QTI9QLIERB2Q9QR"
+IM$(37) = "IBKHIPKHIPKCRB4Q9QSC9CORB8Q9QVI3KHIGRCAQ9QXC9CERCJA9A9A9A9APRCK"
+IM$(38) = "E9E9E9E9EPRCOA9A9A9A9APRCPE9E9E9E9EPRCVA9A9A9A9APRCXE9E9E9E9EP"
+IM$(39) = "RC7A9A9A9A9APRDAE9E9E9E9EP"
+IM$(40) = "RBPQ9QOK9KAQHKNRBQQ9QOI9IWRBVQ9QOKEQHKHQHKPQHKFRBWQ9QPI9IPRB1Q9"
+IM$(41) = "QQKCIPKHIPKHIDRB3Q9QSC9CORB7Q9QUIWKHIPRB9Q9QWC9CGRCEA9A9A9A9AP"
+IM$(42) = "RCFE9E9E9E9EPRCGA9A9A9A9APRCHE9E9E9E9EPRCPA9A9A9A9APRCQE9E9E9E9"
+IM$(43) = "EPRCXA9A9A9A9APRCZE9E9E9E9EPRDAA9A9A9A9APRDCE9E9E9E9EP"
+IM$(44) = "RBOQ9QNK3QHKWRBPQ9QOI9IWRBUQ9QTKHQHKPQHKNRBVQ9QOI9IWRB0Q9QQIKKH"
+IM$(45) = "IPKHIHKDRB1Q9QQC9CSRB2Q9QRC9CQRB6Q9QTIPKHIYRB8Q9QVC9CIRCKA9A9A9"
+IM$(46) = "A9APRCLE9E9E9E9EPRCQA9A9A9A9APRCRE9E9E9E9EPRCZA9A9A9A9APRC1E9E9"
+IM$(47) = "E9E9EPRDCA9A9A9A9APRDFE9E9E9E9EP"
+IM$(48) = "RBOQ9QNI9IYRBTQ9QOKEQHKPQHKVRBUQ9QTI9IRRBZQ9QTKHQHKPQHKHRB0Q9QQ"
+IM$(49) = "C9CSRB5Q9QTIHKHI5KARB7Q9QUC9CKRCBQ9QYI9ICRCHA9A9A9A9APRCIE9E9E9"
+IM$(50) = "E9EPRCLA9A9A9A9APRCME9E9E9E9EPRCRA9A9A9A9APRCTE9E9E9E9EPRC1A9A9"
+IM$(51) = "A9A9APRC3E9E9E9E9EPRDFA9A9A9A9APRDIE9E9E9E9EP"
+IM$(52) = "RBSQ9QTKPQHK3RBTQ9QOI9IWRBYQ9QPKDQHKPQHKHRBZQ9QTI9ILRB4Q9QSIAKH"
+IM$(53) = "I5KHIBRB6Q9QTC9CMRCAQ9QXI9IERCEE9E9E9E9EPRCFA9A9A9A9APRCGE9E9E9"
+IM$(54) = "E9EPRCMA9A9A9A9APRCNE9E9E9E9EPRCTA9A9A9A9APRCUE9E9E9E9EPRC3A9A9"
+IM$(55) = "A9A9APRC5E9E9E9E9EPRDIA9A9A9A9AP"
 REM  ---- PICTURE-END
 SS# = 0
 SE# = NS# - 1
@@ -776,11 +816,12 @@ REM =====================================================================
 REM  Subroutines.
 REM =====================================================================
 
-REM  Chapter 17's generator, verbatim: there is no RND in this dialect.
+REM  Chapter 17's historical generator, verbatim. RND(n) is built in now;
-REM  Answers 0 to RMAX#-1 in RND#, from the middle bits of the seed.
+REM  this stays so the demo runs identically on every machine.
+REM  Answers 0 to RMAX#-1 in ROLL#, from the middle bits of the seed.
 LABEL RANDOM
 SEED# = MOD(((SEED# * 1103515245) + 12345), 2147483648)
-RND# = MOD((SEED# / 65536), RMAX#)
+ROLL# = MOD((SEED# / 65536), RMAX#)
 RETURN
 
 REM  NS# stars in four brightnesses. Two LCG pulls a star, and the
@@ -790,10 +831,10 @@ SI# = 0
 DO WHILE SI# < NS#
   RMAX# = W#
   GOSUB RANDOM
-  X# = RND#
+  X# = ROLL#
   RMAX# = H#
   GOSUB RANDOM
-  Y# = RND#
+  Y# = ROLL#
   B# = MOD(SEED#, 4)
   COLOR 1, STC#(B#)
   DRAW 1, X#, Y#
@@ -1251,7 +1292,7 @@ LABEL REHOME
 MOVSPR L2#, 0.5 * W#, 0.5 * H#
 RMAX# = 360
 GOSUB RANDOM
-SBG#(L2#) = RND#
+SBG#(L2#) = ROLL#
 MOVSPR L2#, SBG#(L2#) # 5
 RETURN
 
@@ -1317,13 +1358,25 @@ TB# = TB# + 1
 IF TB# > 2 THEN TB# = 0
 RETURN
 
+REM  A batch is four PLAY statements, one bar each: the parser's V, T,
+REM  U and duration state persists across statements and every PLAY
+REM  appends to the same queue, so four bars queue exactly as one long
+REM  string would -- which the 80-column line limit no longer allows.
+REM  Each bar restates the prefix anyway, so a bar dropped by QFULL
+REM  never leaves the next one playing with drum-kit state.
 LABEL TUNEA
-PLAY "V1T3U9S O1AO2AO3AO2AO3AO4CEAO1AO2AO4CEAO5CO4AE O1FO2FO3FO2FO3FAO4CFO1FO2FO3AO4CFAO5CO4A O1CO2CO3CO2CO3CEGO4CO1CO2CO3EGO4CEGO5C O1GO2GO3GO2GO3GBO4DGO1GO2GO3BO4DGBO5DO4B"
+PLAY "V1T3U9S O1AO2AO3AO2AO3AO4CEAO1AO2AO4CEAO5CO4AE"
+PLAY "V1T3U9S O1FO2FO3FO2FO3FAO4CFO1FO2FO3AO4CFAO5CO4A"
+PLAY "V1T3U9S O1CO2CO3CO2CO3CEGO4CO1CO2CO3EGO4CEGO5C"
+PLAY "V1T3U9S O1GO2GO3GO2GO3GBO4DGO1GO2GO3BO4DGBO5DO4B"
 MT# = TI# + 270
 RETURN
 
 LABEL TUNEB
-PLAY "V1T3U9S O1AO2AO3AO2AO3AO4CEAO1AO2AO4CEAO5CEO4A O1FO2FO3FO2FO3FAO4CFO1FO2FO3AO4CFAO5CO4A O1DO2DO3DO2DO3DFAO4DO1DO2DO3FAO4DFAO5D O1EO2EO3EO2EO3E#GBO4EO1EO2EO3#GBO4E#GBO5E"
+PLAY "V1T3U9S O1AO2AO3AO2AO3AO4CEAO1AO2AO4CEAO5CEO4A"
+PLAY "V1T3U9S O1FO2FO3FO2FO3FAO4CFO1FO2FO3AO4CFAO5CO4A"
+PLAY "V1T3U9S O1DO2DO3DO2DO3DFAO4DO1DO2DO3FAO4DFAO5D"
+PLAY "V1T3U9S O1EO2EO3EO2EO3E#GBO4EO1EO2EO3#GBO4E#GBO5E"
 MT# = TI# + 270
 RETURN
 

examples/megademo/vaporwave.py

@@ -58,7 +58,14 @@ SKIP = "Q"
 ROWREC = "R"
 LENCH = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
 MAXRUN = len(LENCH)
-PAYLOAD = 240
+
+# The interpreter reads source through an 80-byte line buffer and refuses
+# any line that fills it (AKBASIC_MAX_LINE_LENGTH, sink_stdio.c), so a
+# stored line is at most 78 characters plus its newline. 'IM$(NN) = "' and
+# the closing quote spend 12 of those; 64 keeps the emitted lines under
+# the ceiling with margin to spare while the index stays two digits.
+PAYLOAD = 64
+MAXLINE = 78
 
 SUN_CX, SUN_CY, SUN_R = 80, 50, 30
 HORIZON = 74
@@ -206,13 +213,32 @@ def encode_delta(prev, cur):
 
 
 def chop(blob):
-    return [blob[i:i + PAYLOAD] for i in range(0, len(blob), PAYLOAD)]
+    """Split a stream into strings of at most PAYLOAD characters, cutting
+    only between records. The decoder reads a record's tail characters
+    with MID on the string it is walking, so a run (two characters) or a
+    row record (three) that straddled two IM$ entries would decode as
+    garbage; DRAWSTREAM only carries the cursor, never a partial record."""
+    out, cur = [], ""
+    p = 0
+    while p < len(blob):
+        n = 3 if blob[p] == ROWREC else 2
+        if len(cur) + n > PAYLOAD:
+            out.append(cur)
+            cur = ""
+        cur += blob[p:p + n]
+        p += n
+    if cur:
+        out.append(cur)
+    return out
 
 
-def simulate(raster, blob):
+def simulate(raster, blob, x=0, y=0):
     """Apply one encoded stream to a raster exactly the way the BASIC
-    decoder does, skips-draw-nothing and all."""
+    decoder does, skips-draw-nothing and all. The cursor comes in and
-    x = y = p = 0
+    goes back out because DRAWSTREAM carries it from one IM$ entry to
+    the next -- decoding the chopped strings one at a time with the
+    cursor threaded through is exactly what the demo will execute."""
+    p = 0
     while p < len(blob):
         c = blob[p]
         if c == ROWREC:
@@ -230,20 +256,31 @@ def simulate(raster, blob):
             x = 0
             y += 1
         p += 2
+    return raster, x, y
+
+
+def simulate_lines(raster, lines):
+    """One stream as its chopped strings, cursor carried across the
+    boundaries the way DRAWSTREAM carries X# and Y#."""
+    x = y = 0
+    for line in lines:
+        raster, x, y = simulate(raster, line, x, y)
     return raster
 
 
-def verify(frames, base_blob, delta_blobs):
+def verify(frames, base_lines, delta_line_groups):
     """The base must reproduce frame 0 exactly, and each delta must
     carry the raster exactly to the next frame. A skip leaves the cell
     the encoder promised was already right, so equality is total and
-    any difference at all is an encoder bug."""
+    any difference at all is an encoder bug. This decodes the CHOPPED
+    strings, not the blobs, so a chop that split a record would fail
+    here instead of corrupting the screen."""
     raster = [[1] * W for _ in range(H)]
-    raster = simulate(raster, base_blob)
+    raster = simulate_lines(raster, base_lines)
     assert raster == frames[0], "base stream does not reproduce frame 0"
-    for i, blob in enumerate(delta_blobs):
+    for i, lines in enumerate(delta_line_groups):
         want = frames[(i + 1) % PHASES]
-        raster = simulate(raster, blob)
+        raster = simulate_lines(raster, lines)
         assert raster == want, "delta %d does not reproduce its frame" % i
 
 
@@ -261,6 +298,9 @@ def emit_block(base_lines, delta_ranges, all_lines):
     for i, s in enumerate(all_lines):
         out.append('IM$(%d) = "%s"' % (i, s))
     out.append("REM  ---- PICTURE-END")
+    for line in out:
+        assert len(line) <= MAXLINE, "emitted line over %d chars: %r" % (
+            MAXLINE, line)
     return out
 
 
@@ -303,15 +343,15 @@ def main():
     base_lines = chop(base_blob)
     all_lines = list(base_lines)
     delta_ranges = []
-    delta_blobs = []
+    delta_line_groups = []
     for i in range(PHASES):
         blob = encode_delta(frames[i], frames[(i + 1) % PHASES])
-        delta_blobs.append(blob)
         lines = chop(blob)
+        delta_line_groups.append(lines)
         delta_ranges.append((len(all_lines), len(all_lines) + len(lines) - 1))
         all_lines.extend(lines)
-    verify(frames, base_blob, delta_blobs)
+    verify(frames, base_lines, delta_line_groups)
-    dbytes = sum(len(b) for b in delta_blobs)
+    dbytes = sum(len(l) for g in delta_line_groups for l in g)
     print("base %d bytes in %d strings; video %d bytes in %d strings; "
           "%d strings total" %
           (sum(len(s) for s in base_lines), len(base_lines), dbytes,

include/akbasic/error.h

@@ -12,9 +12,12 @@
  * libakerror 2.0.0 is the floor, raised from 1.0.0 because 2.0.0 is an ABI break
  * that a compile against the wrong header cannot survive quietly:
  *
- *   - `__akerr_last_ignored` became thread-local. `IGNORE` expands at *our* call
+ *   - The context behind `IGNORE` became thread-local. `IGNORE` expands at *our*
- *     site, so our objects reference that symbol under whichever storage model
+ *     call site, so our objects reference that storage under whichever model the
- *     the header on the include path declared.
+ *     header on the include path declared. 2.0.2 went further and made it a
+ *     per-translation-unit `static` snapshot named `akerr_last_ignored`, copied
+ *     from the pool slot so the slot can be released; the old spelling
+ *     `__akerr_last_ignored` was an `extern` pointer and no longer exists.
  *   - `akerr_next_error()` now returns a context that already holds a reference,
  *     and `ENSURE_ERROR_READY` no longer increments. Objects compiled against a
  *     1.x header count every reference twice and never give a slot back.

include/akbasic/runtime.h

@@ -252,6 +252,11 @@ typedef struct akbasic_Runtime
      */
     int64_t timems;
 
+    /* RND's lazy seed state. The flag distinguishes an unseeded run from a
+     * legitimate LCG state of zero. */
+    int64_t rndseed;
+    bool rndseeded;
+
     /*
      * Set by a branch that has decided the remaining statements on its line
      * belong to the arm it did not take, and cleared at the top of every line.

scripts/mutation_test.py

@@ -282,9 +282,8 @@ def copy_tree(src, dst):
     # and a coverage tree drags along every .gcno/.gcda as well.
     #
     # deps/ is copied wholesale and has to be: the build pulls libakerror and
-    # libakstdlib in with add_subdirectory. The golden corpus used to be the
+    # libakstdlib in with add_subdirectory. The language corpus is the other
-    # other reason -- it was driven in place out of deps/basicinterpret -- and
+    # reason it comes along with the rest of the tree.
-    # now lives in tests/reference/, which comes along with the rest of the tree.
     # Only vendored Windows DLLs are dead weight, hence "*.dll".
     #
     # **PNGs are ours or theirs, and the difference matters.** This used to drop

src/runtime.c

@@ -893,7 +893,7 @@ akerr_ErrorContext *akbasic_runtime_interpret(akbasic_Runtime *obj, akbasic_ASTL
 	     *
 	     * **Only a block skip**, which is what the `BEND` test is for. A
 	     * zero-iteration `FOR` skips its body the same way, and there the
-	     * orphan is load-bearing: `tests/reference/.../nestedforloopwaiting
+	     * orphan is load-bearing: `tests/language/.../nestedforloopwaiting
 	     * forcommand.bas` nests a loop inside one that runs zero times, and
 	     * the inner scope is what absorbs the inner `NEXT` so the outer `NEXT`
 	     * still finds its `FOR`. Popping it there turns that case into "NEXT
@@ -1286,7 +1286,7 @@ akerr_ErrorContext *akbasic_runtime_process_line_runstream(akbasic_Runtime *obj)
      * This mode used to file it like any other, under the cursor -- which for a
      * blank line is the number of the line *before* it. A file ending in a blank
      * line therefore had its last line erased before it ever ran, silently. The
-     * reference did the same, and `tests/reference/language/arithmetic/integer.bas`
+     * reference did the same, and `tests/language/arithmetic/integer.bas`
      * has an expectation with three values for four PRINT statements to prove it.
      */
     if ( buffer[0] == '\0' ) {

src/runtime_disk.c

@@ -407,17 +407,22 @@ akerr_ErrorContext *akbasic_cmd_directory(akbasic_Runtime *obj, akbasic_ASTLeaf
     FAIL_ZERO_RETURN(errctx, (obj != NULL && dest != NULL), AKERR_NULLPOINTER,
 		     "NULL argument in DIRECTORY");
     /*
-     * Refused rather than half-built. Listing a directory needs opendir/readdir,
+     * Refused rather than half-built. This was blocked upstream: listing a
-     * which `libakstdlib` does not wrap -- and this project's rule is that a
+     * directory needs opendir/readdir, `libakstdlib` did not wrap them, and
-     * missing capability gets filed upstream rather than worked around here
+     * this project's rule is that a missing capability gets filed upstream
-     * (MAINTENANCE.md). Filed as libakstdlib issue #10.
+     * rather than worked around here (MAINTENANCE.md). That was libakstdlib
+     * issue #10, and it landed -- aksl_opendir, aksl_readdir, aksl_closedir
+     * and aksl_rewinddir all exist as of the revision this tree pins.
      *
-     * The alternative was shelling out to `ls`, which a library has no business
+     * So the blocker is gone and only the work is left. Writing the verb needs
-     * doing, or calling readdir directly and stepping outside the error
+     * decisions this commit is not the place for: what a listing looks like on
-     * convention every other call in this file follows.
+     * a filesystem with no disk-image block counts, which of the Commodore
+     * wildcard forms to honour, and where the entries go. Tracked as akbasic
+     * issue #55; the refusal stays honest until then rather than growing a
+     * half-listing nobody specified.
      */
     FAIL_RETURN(errctx, AKBASIC_ERR_DEVICE,
-		"DIRECTORY is not implemented: libakstdlib has no directory-reading wrapper yet");
+		"DIRECTORY is not implemented yet");
 }
 
 /* ------------------------------------------------------------ BSAVE/BLOAD -- */

src/runtime_functions.c

@@ -183,6 +183,69 @@ akerr_ErrorContext *akbasic_fn_chr(akbasic_Runtime *obj, akbasic_ASTLeaf *expr,
     SUCCEED_RETURN(errctx);
 }
 
+akerr_ErrorContext *akbasic_fn_asc(akbasic_Runtime *obj, akbasic_ASTLeaf *expr, akbasic_Value *lval, akbasic_Value *rval, akbasic_Value **dest)
+{
+    PREPARE_ERROR(errctx);
+    akbasic_Value *arg = NULL;
+    akbasic_Value *out = NULL;
+    const unsigned char *text = NULL;
+    int64_t codepoint = 0;
+
+    (void)lval; (void)rval;
+    PASS(errctx, first_arg(obj, expr, "ASC", NULL, &arg, &out));
+    FAIL_NONZERO_RETURN(errctx, (arg->valuetype != AKBASIC_TYPE_STRING), AKBASIC_ERR_TYPE,
+			"ASC expected a string");
+    FAIL_ZERO_RETURN(errctx, (arg->stringval[0] != '\0'), AKBASIC_ERR_BOUNDS,
+		     "ASC expected a non-empty string");
+
+    /* Decode the first UTF-8 code point, the inverse of CHR's encoder. */
+    text = (const unsigned char *)arg->stringval;
+    if ( text[0] < 0x80 ) {
+	codepoint = text[0];
+    } else if ( (text[0] & 0xE0) == 0xC0 ) {
+	codepoint = ((int64_t)(text[0] & 0x1F) << 6) |
+		    (text[1] & 0x3F);
+    } else if ( (text[0] & 0xF0) == 0xE0 ) {
+	codepoint = ((int64_t)(text[0] & 0x0F) << 12) |
+		    ((int64_t)(text[1] & 0x3F) << 6) |
+		    (text[2] & 0x3F);
+    } else {
+	codepoint = ((int64_t)(text[0] & 0x07) << 18) |
+		    ((int64_t)(text[1] & 0x3F) << 12) |
+		    ((int64_t)(text[2] & 0x3F) << 6) |
+		    (text[3] & 0x3F);
+    }
+    out->valuetype = AKBASIC_TYPE_INTEGER;
+    out->intval = codepoint;
+    *dest = out;
+    SUCCEED_RETURN(errctx);
+}
+
+akerr_ErrorContext *akbasic_fn_rnd(akbasic_Runtime *obj, akbasic_ASTLeaf *expr, akbasic_Value *lval, akbasic_Value *rval, akbasic_Value **dest)
+{
+    PREPARE_ERROR(errctx);
+    akbasic_Value *arg = NULL;
+    akbasic_Value *out = NULL;
+    const int64_t modulus = 2147483648;
+
+    (void)lval; (void)rval;
+    PASS(errctx, first_arg(obj, expr, "RND", NULL, &arg, &out));
+    FAIL_NONZERO_RETURN(errctx, (arg->valuetype != AKBASIC_TYPE_INTEGER), AKBASIC_ERR_TYPE,
+			"RND expected an integer");
+    FAIL_ZERO_RETURN(errctx, (arg->intval > 0), AKBASIC_ERR_VALUE,
+		     "RND count %" PRId64 " must be positive", arg->intval);
+
+    if ( !obj->rndseeded ) {
+	obj->rndseed = obj->timems % modulus;
+	obj->rndseeded = true;
+    }
+    obj->rndseed = (obj->rndseed * 1103515245 + 12345) % modulus;
+    out->valuetype = AKBASIC_TYPE_INTEGER;
+    out->intval = (obj->rndseed / 65536) % arg->intval;
+    *dest = out;
+    SUCCEED_RETURN(errctx);
+}
+
 akerr_ErrorContext *akbasic_fn_hex(akbasic_Runtime *obj, akbasic_ASTLeaf *expr, akbasic_Value *lval, akbasic_Value *rval, akbasic_Value **dest)
 {
     PREPARE_ERROR(errctx);

src/verbs.c

@@ -37,6 +37,7 @@ static const akbasic_Verb VERBS[] = {
     { "ABS",          AKBASIC_TOK_FUNCTION,              1, NULL,                  akbasic_fn_abs },
     { "AND",          AKBASIC_TOK_AND,                  -1, NULL,                  NULL },
     { "APPEND",       AKBASIC_TOK_COMMAND,              -1, akbasic_parse_arglist, akbasic_cmd_append },
+    { "ASC",          AKBASIC_TOK_FUNCTION,              1, NULL,                  akbasic_fn_asc },
     { "ATN",          AKBASIC_TOK_FUNCTION,              1, NULL,                  akbasic_fn_atn },
     { "AUTO",         AKBASIC_TOK_COMMAND_IMMEDIATE,    -1, NULL,                  akbasic_cmd_auto },
     { "BACKUP",       AKBASIC_TOK_COMMAND,              -1, akbasic_parse_optional_arglist, akbasic_cmd_backup },
@@ -146,6 +147,7 @@ static const akbasic_Verb VERBS[] = {
     { "RGR",          AKBASIC_TOK_FUNCTION,              1, NULL,                  akbasic_fn_rgr },
     { "RIGHT",        AKBASIC_TOK_FUNCTION,              2, NULL,                  akbasic_fn_right },
     { "RMENU",        AKBASIC_TOK_FUNCTION,              2, NULL,                  akbasic_fn_rmenu },
+    { "RND",          AKBASIC_TOK_FUNCTION,              1, NULL,                  akbasic_fn_rnd },
     { "RSPCOLOR",     AKBASIC_TOK_FUNCTION,              1, NULL,                  akbasic_fn_rspcolor },
     { "RSPHIT",       AKBASIC_TOK_FUNCTION,              2, NULL,                  akbasic_fn_rsphit },
     { "RSPPOS",       AKBASIC_TOK_FUNCTION,              2, NULL,                  akbasic_fn_rsppos },

src/verbs.h

@@ -140,6 +140,7 @@ akerr_ErrorContext AKERR_NOIGNORE *akbasic_cmd_stop(struct akbasic_Runtime *obj,
 
 /* Function handlers -- src/runtime_functions.c */
 akerr_ErrorContext AKERR_NOIGNORE *akbasic_fn_abs(struct akbasic_Runtime *obj, akbasic_ASTLeaf *expr, akbasic_Value *lval, akbasic_Value *rval, akbasic_Value **dest);
+akerr_ErrorContext AKERR_NOIGNORE *akbasic_fn_asc(struct akbasic_Runtime *obj, akbasic_ASTLeaf *expr, akbasic_Value *lval, akbasic_Value *rval, akbasic_Value **dest);
 akerr_ErrorContext AKERR_NOIGNORE *akbasic_fn_atn(struct akbasic_Runtime *obj, akbasic_ASTLeaf *expr, akbasic_Value *lval, akbasic_Value *rval, akbasic_Value **dest);
 akerr_ErrorContext AKERR_NOIGNORE *akbasic_fn_chr(struct akbasic_Runtime *obj, akbasic_ASTLeaf *expr, akbasic_Value *lval, akbasic_Value *rval, akbasic_Value **dest);
 akerr_ErrorContext AKERR_NOIGNORE *akbasic_fn_cos(struct akbasic_Runtime *obj, akbasic_ASTLeaf *expr, akbasic_Value *lval, akbasic_Value *rval, akbasic_Value **dest);
@@ -154,6 +155,7 @@ akerr_ErrorContext AKERR_NOIGNORE *akbasic_fn_peek(struct akbasic_Runtime *obj,
 akerr_ErrorContext AKERR_NOIGNORE *akbasic_fn_pointer(struct akbasic_Runtime *obj, akbasic_ASTLeaf *expr, akbasic_Value *lval, akbasic_Value *rval, akbasic_Value **dest);
 akerr_ErrorContext AKERR_NOIGNORE *akbasic_fn_pointervar(struct akbasic_Runtime *obj, akbasic_ASTLeaf *expr, akbasic_Value *lval, akbasic_Value *rval, akbasic_Value **dest);
 akerr_ErrorContext AKERR_NOIGNORE *akbasic_fn_rad(struct akbasic_Runtime *obj, akbasic_ASTLeaf *expr, akbasic_Value *lval, akbasic_Value *rval, akbasic_Value **dest);
+akerr_ErrorContext AKERR_NOIGNORE *akbasic_fn_rnd(struct akbasic_Runtime *obj, akbasic_ASTLeaf *expr, akbasic_Value *lval, akbasic_Value *rval, akbasic_Value **dest);
 akerr_ErrorContext AKERR_NOIGNORE *akbasic_fn_right(struct akbasic_Runtime *obj, akbasic_ASTLeaf *expr, akbasic_Value *lval, akbasic_Value *rval, akbasic_Value **dest);
 akerr_ErrorContext AKERR_NOIGNORE *akbasic_fn_sgn(struct akbasic_Runtime *obj, akbasic_ASTLeaf *expr, akbasic_Value *lval, akbasic_Value *rval, akbasic_Value **dest);
 akerr_ErrorContext AKERR_NOIGNORE *akbasic_fn_shl(struct akbasic_Runtime *obj, akbasic_ASTLeaf *expr, akbasic_Value *lval, akbasic_Value *rval, akbasic_Value **dest);

tests/disk_verbs.c

@@ -244,10 +244,16 @@ static void test_no_drive_verbs(void)
 	harness_stop();
     }
 
-    /* DIRECTORY is refused for a different reason, and says which. */
+    /*
+     * DIRECTORY is refused for a different reason than the five above: not for
+     * want of a drive, but because it is unwritten. It used to name the missing
+     * libakstdlib wrapper; that wrapper landed, so naming it would be a lie.
+     */
     TEST_REQUIRE_OK(run_program("10 DIRECTORY\n"));
-    TEST_REQUIRE(strstr(HARNESS_OUTPUT, "libakstdlib") != NULL,
+    TEST_REQUIRE(strstr(HARNESS_OUTPUT, "not implemented") != NULL,
-		 "DIRECTORY should name the missing wrapper, got \"%s\"", HARNESS_OUTPUT);
+		 "DIRECTORY should say it is unwritten, got \"%s\"", HARNESS_OUTPUT);
+    TEST_REQUIRE(strstr(HARNESS_OUTPUT, "libakstdlib") == NULL,
+		 "DIRECTORY must not still blame libakstdlib, got \"%s\"", HARNESS_OUTPUT);
     harness_stop();
 }
 

tests/for_semantics.c

@@ -81,7 +81,7 @@ static void test_counter_survives_the_loop(void)
  * `FOR I = 1 TO 1` executes the body one time on every BASIC there has ever
  * been. Here the entry test treats "the counter has reached the limit" as
  * "do not enter", so the body is skipped entirely -- and
- * tests/reference/language/flowcontrol/forloopwaitingforcommand.bas pins that,
+ * tests/language/flowcontrol/forloopwaitingforcommand.bas pins that,
  * which is why this cannot simply be corrected.
  */
 static void test_single_iteration_loop(void)

tests/language/README.md

@@ -0,0 +1,16 @@
+# The language test corpus
+
+The `.bas` files in this directory and their sibling `.txt` files are the editable language
+corpus. CMake registers every program as an individual `local_*` CTest case and compares its
+output with the sibling expectation.
+
+The corpus includes cases carried over from the deprecated Go implementation as well as cases
+written for this interpreter. Their provenance is useful when investigating a regression, but it
+does not make any case immutable or turn the old implementation into a specification.
+
+**Change a program and its expectation deliberately and in the same commit.** If the changed
+output represents an intentional language decision, record the reason in `TODO.md` or the
+relevant documentation. If it is an accidental change, fix the interpreter instead.
+
+The `examples/` subdirectory contains complete BASIC programs used as worked examples. It is
+part of the same corpus and follows the same `.bas`/`.txt` pairing rule.

tests/language/arrays_in_parameter_lists.bas

@@ -1,6 +1,6 @@
 10 REM An array reference used as a function argument, and as one of several.
 20 REM An identifier's subscript list used to hang off .right, which is also
-30 REM where an argument list chains its arguments -- so the arity counter walked
+30 REM where arguments chain their arguments -- so the arity counter walked
 40 REM straight into the subscripts and refused the call. TODO.md section 4.
 50 DIM C#(4)
 60 C#(1) = -9

tests/language/audio/filter_refused.bas

@@ -1,6 +1,6 @@
-10 REM FILTER has no device capability behind it -- akgl_audio_* synthesises and
+10 REM FILTER has no device capability -- audio synthesises and mixes but
-20 REM mixes but has no filter stage, and SDL3 supplies no primitive to build one
+20 REM has no filter stage; SDL3 supplies no primitive to build one from. It
-30 REM from. It is refused rather than silently ignored, so a program that asked
+30 REM is refused rather than silently ignored, so a program that asked
 40 REM for a low-pass finds out it did not get one.
 50 PRINT "BEFORE"
 60 FILTER 1000, 1, 0, 0, 5

tests/language/audio/no_device.bas

@@ -1,4 +1,4 @@
-10 REM The standalone driver lends the script no audio device. ENVELOPE, VOL and
+10 REM The standalone driver has no audio device. ENVELOPE, VOL and
 20 REM TEMPO only change interpreter state, so they work regardless; SOUND and
 30 REM PLAY need the device and must name themselves when there is none.
 40 ENVELOPE 1, 5, 9, 12, 2

tests/language/flowcontrol/nestedforloopwaitingforcommand.bas

@@ -1,6 +1,6 @@
 10 REM This shows the waitingForCommand utility in the BasicEnvironment
 11 REM when we have a nested for loop. The inner loop SHOULD execute, but
-12 REM the outer loop should NOT execute. Therefore, neither loop should execute.
+12 REM the outer loop should NOT execute. Neither loop should execute.
 20 FOR I# = 1 TO 0
 25 FOR J# = 2 TO 4
 30 PRINT "waitingForCommand FAILS if this is seen"
@@ -8,4 +8,4 @@
 35 NEXT J#
 40 NEXT I#
 50 PRINT "SUCCESS"
-80 QUIT
+80 QUIT

tests/language/functions/asc.bas

@@ -0,0 +1,3 @@
+10 PRINT "97 : " + ASC("a")
+20 PRINT "65 : " + ASC("A")
+30 PRINT "64 : " + ASC("@")

tests/language/functions/asc.txt

@@ -0,0 +1,3 @@
+97 : 97
+65 : 65
+64 : 64

tests/language/functions/mod.bas

@@ -1,6 +1,6 @@
 10 PRINT MOD(10, 3)
 20 PRINT MOD(12, 5)
 30 PRINT MOD(4, 2)
-40 REM MOD() ONLY WORKS WITH INTEGERS - RESULTS WITH FLOATING POINT ARE UNRELIABLE
+40 REM MOD() ONLY WORKS WITH INTEGERS - FLOATING-POINT RESULTS ARE UNRELIABLE
 50 REM PRINT MOD(1.2, 0.4)
 60 REM THERE IS NO ERROR THROWN HERE. JUST DONT DO IT.

tests/language/functions/recursion.bas

@@ -1,6 +1,6 @@
-10 REM A DEF call takes its environment from the pool, one per call, exactly as
+10 REM A DEF call takes an environment from the pool, one per call, exactly as
 20 REM GOSUB does. It used to be owned by the funcdef and reset on every call,
-30 REM which cost two silent defects: two calls in one expression shared a slot,
+30 REM which cost two silent defects: two calls shared a slot,
 40 REM and recursion never came back at all.
 50 DEF FACT(N#)
 60 IF N# <= 1 THEN RETURN 1
@@ -15,9 +15,9 @@
 150 DEF DBL(N#) = N# * 2
 160 PRINT DBL(10) + DBL(1)
 170 PRINT DBL(1) + DBL(10) + DBL(100)
-180 REM Depth answers to the environment pool now, so runaway recursion reports
+180 REM Depth answers to the pool, so runaway recursion reports
-190 REM "Environment pool exhausted" rather than hanging. It is not exercised here
+190 REM "Environment pool exhausted" rather than hanging. It is not exercised
-200 REM because the statement containing a failed call still prints a junk value
+200 REM here because a failed call's statement still prints a junk value
-210 REM afterwards -- a separate, pre-existing defect recorded in TODO.md, and one
+210 REM afterwards -- a TODO.md defect this file would pin
-220 REM this golden file would pin if it went in. tests/user_functions.c asserts
+220 REM if it went in. tests/user_functions.c asserts
 230 REM the message instead.