Add native RND and ASC functions

Implement bounded random integers with lazy clock seeding and add ASC as the inverse of CHR. Cover dispatch, validation, deterministic LCG output, UTF-8 round trips, function reference, and the breakout tutorial.

Closes #16.

Co-authored-by: andrew <andrew@aklabs.net>

CMakeLists.txt

@@ -51,14 +51,12 @@ option(AKBASIC_SANITIZE  "Build with ASan + UBSan"                           OFF
 # through: the dependencies set target and directory properties that their own
 # builds depend on.
 #
-# All three dependencies now namespace both their `coverage` and their
-# `mutation` targets when embedded, so there is no custom-target collision left
-# to work around. libakerror was the last holdout -- it namespaced `mutation`
-# but not `coverage`, and a coverage build collided on the bare name and failed
-# to configure at all. 2.0.2 applies the same CMAKE_SOURCE_DIR test to both
-# (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.
+# libakerror additionally namespaces its `mutation` target when embedded but not
+# its `coverage` target (deps/libakerror/CMakeLists.txt:194 vs :172), so a
+# coverage build collides on the `coverage` target and fails to configure at all.
+# Rename the dependency's on the way past. Remove this once libakerror applies
+# the same CMAKE_SOURCE_DIR test to `coverage` that it already applies to
+# `mutation` -- filed as libakerror issue #15.
 #
 # **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
@@ -88,6 +86,14 @@ 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)

MAINTENANCE.md

@@ -68,19 +68,12 @@ 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. **Five** gaps were filed this way and all five landed upstream: text measurement,
-immediate-mode drawing, audio and a non-blocking keystroke read became `akgl_text_measure`,
-the `akgl_draw_*` family, `akgl_audio_*` and `akgl_controller_poll_key`; and the
-directory-reading wrapper `DIRECTORY` was waiting on became `aksl_opendir`, `aksl_readdir`,
-`aksl_closedir` and `aksl_rewinddir` — `libakstdlib` issue #10, in the revision this tree
-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.
+It works. Four gaps were filed this way — text measurement, immediate-mode drawing, audio,
+and a non-blocking keystroke read — and all four landed upstream as `akgl_text_measure`, the
+`akgl_draw_*` family, `akgl_audio_*` and `akgl_controller_poll_key`. `FILTER` is the one verb
+still blocked on a gap, and `DIRECTORY` is refused pending an `opendir`/`readdir` wrapper in
+`libakstdlib`. 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
 
@@ -163,10 +156,10 @@ 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 **2.0.2**, whose 2.0.0
+That order is load-bearing for a second reason: `deps/libakerror` is at **2.0.1**, 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: the context behind `IGNORE` became
+not be picked up. The break is quiet if you get it wrong: `__akerr_last_ignored` 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.
 
@@ -174,47 +167,10 @@ a mixed build leaks pool slots or frees one twice rather than failing to link.
 
 | Submodule | Version | soname | ABI rule | Version API |
 |---|---|---|---|---|
-| `deps/libakerror` | 2.0.2 | `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/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/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
@@ -240,32 +196,16 @@ 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` used to be asymmetric. It no longer is.**
+**Version-pinning in `find_package` is asymmetric, and that is deliberate.**
 `find_package(akstdlib 0.1)` and `find_package(akgl 0.1)` both work; each ships a
-`ConfigVersion.cmake` at `SameMinorVersion`, mirroring its soname. `libakerror` shipped
-`akerrorConfig.cmake` and `akerrorTargets.cmake` but no `akerrorConfigVersion.cmake`, so any
-versioned request failed against a correct install and the advice here was to ask for
-`akerror` unversioned. That was `libakerror` issue #16 — closed — and `libakstdlib` issue #5,
-which tracks the same fix from the other side and is still open only because nobody has shut
-it. It has landed: `libakerror` now writes `akerrorConfigVersion.cmake` at
-**`SameMajorVersion`**, matching the soname's major-only rule, rather than the
-`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.
+`ConfigVersion.cmake` at `SameMinorVersion`, mirroring its soname. `find_package(akerror 1.0)`
+**fails against a correct install**, because `libakerror` ships `akerrorConfig.cmake` and
+`akerrorTargets.cmake` but no `akerrorConfigVersion.cmake`. Ask for `akerror` unversioned. Its
+floor is enforced instead by 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 the guard. The missing version file is filed in
+`libakstdlib` issue #5 and `libakerror` issue #16; when it lands, add the `1.0` floor to the `find_dependency`
+calls.
 
 ### Embedding all three dependencies collides four ways
 
@@ -310,19 +250,14 @@ 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 — fixed upstream, and the workaround is gone.** `libakerror`
-used to namespace its `mutation` target when embedded but **not** its `coverage` target, so
-any coverage-enabled top-level build failed with *"another target with the same name already
-exists"*. This project shadowed `add_custom_target` and renamed that one to
-`akerror_coverage` on the way past, and recorded the real fix as `libakerror` issue #15: the
-same `CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR` test it already applied to
-`mutation`.
-
-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.
+**3. Duplicate custom targets.** `libakerror` namespaces its `mutation` target when embedded
+but **not** its `coverage` target, so any coverage-enabled top-level build fails with *"another
+target with the same name already exists"*. We shadow `add_custom_target` and rename that one
+to `akerror_coverage` on the way past. `libakstdlib` (both targets) and `libakgl` (its
+`mutation` target) namespace themselves correctly. **The real fix is upstream in
+`libakerror`** — the same `CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR` test it already
+applies to `mutation` — and it is filed as `libakerror` issue #15. Delete the
+workaround when it lands.
 
 **4. Stale build trees poison the coverage report.** See below; it is the reason for
 `cmake -S . -B build`.

README.md

@@ -138,13 +138,12 @@ 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) 2.0.2 — TRY/CATCH-style error
+* [libakerror](https://source.starfort.tech/andrew/libakerror) 2.0.1 — 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`. Its public header now also pulls in
-  `<dirent.h>` and `<sys/stat.h>` for the directory and file-metadata wrappers.
+  `VAL("garbage")` is an error rather than a silent `0`.
 * [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

@@ -2339,9 +2339,9 @@ Dependency baseline:
 
 | Submodule | Version | Notes |
 |---|---|---|
-| `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. 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` | 0.9.0 | 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. |
+| `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/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/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. |
 
 **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

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` | not written yet. It was blocked on a directory-reading wrapper in the standard library; that landed, so only the verb is outstanding |
+| `DIRECTORY` / `CATALOG` | needs a directory-reading wrapper the standard library does not have yet. Filed upstream |
 
 `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.** Not written yet; the standard-library wrapper it waited on has landed. |
+| `DIRECTORY` | `DIRECTORY` | **Refused.** Needs a directory-reading wrapper that does not exist yet. |
 | `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/13-differences.md

@@ -199,8 +199,7 @@ 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** because it is not written yet. The standard-library
-  wrapper it was waiting on has landed, so the remaining work is the verb.
+- **`DIRECTORY` is refused** pending a wrapper in the standard library.
 
 ## Machine
 

docs/17-tutorial-breakout.md

@@ -1049,17 +1049,17 @@ every program. It remains a useful from-scratch PRNG example:
 ```basic norun
 SEED# = 12345
 RMAX# = 6
-ROLL# = 0
+RND# = 0
 I# = 0
 FOR I# = 1 TO 5
   GOSUB RANDOM
-  PRINT "ROLL " + (ROLL# + 1)
+  PRINT "ROLL " + (RND# + 1)
 NEXT I#
 END
 
 LABEL RANDOM
 SEED# = MOD(((SEED# * 1103515245) + 12345), 2147483648)
-ROLL# = MOD((SEED# / 65536), RMAX#)
+RND# = MOD((SEED# / 65536), RMAX#)
 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 hand the script dice the engine controls
+  and give the script randomness it cannot make itself
 - **[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: fresh 0..1 each call; ROLL% in BASIC	*/
+    float    rnd;	/* inbox: engine writes fresh 0..1 each call	*/
 } 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,    "ROLL%",    AKBASIC_HOSTFIELD_FLOAT )
+    AKBASIC_HOST_FIELD( galaga_Enemy, rnd,    "RND%",     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; ROLL% to the script	*/
+    float    rnd;	/* fresh 0..1 each frame; the issue #16 route	*/
 } galaga_Shared;
 ```
 
@@ -203,24 +203,13 @@ 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 — carry the
-engine's PRNG into the script: write `SELF@.ROLL% < DT% * 1.5` and an enemy's
-trigger finger is a dice roll.
-
-The dialect does now have a native `RND` function — issue #16 closed, and
-[Chapter 12](12-function-reference.md) documents it — so this is no longer the
-*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.
+The `rnd` fields — one here per frame, one on each enemy per call — exist
+because the engine's PRNG is the script's **only** source of randomness: write
+`SELF@.RND% < DT% * 1.5` and an enemy's trigger finger is a dice roll. There
+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
+route. Here the engine fills the field, which also keeps a headless run the
+same game on every machine — the PRNG is the example's own, not libc's.
 
 ## Step 4: Why bindings, and not arguments
 
@@ -362,7 +351,7 @@ 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@.ROLL% < DT% * 1.5 THEN SELF@.FIRE# = 1
+  IF SELF@.RND% < DT% * 1.5 THEN SELF@.FIRE# = 1
   RETURN 0
 END
 ```
@@ -397,7 +386,7 @@ 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@.ROLL% < DT% * 0.04 THEN SELF@.STATE# = 4 : SELF@.T% = 0
+    IF SELF@.RND% < 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
-ROLL# = 0
+RND# = 0
 SND# = 0
 P$ = ""
 H$ = ""
@@ -172,8 +172,7 @@ BSG$(4) = "[--]"
 BSG$(5) = "[--]"
 
 REM --- the seed -------------------------------------------------------
-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 There is no RND in this dialect. 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#
 
@@ -390,18 +389,17 @@ BY# = PY# - 10
 RMAX# = 2
 GOSUB RANDOM
 BVX# = BSPD#
-IF ROLL# = 0 THEN BVX# = 0 - BSPD#
+IF RND# = 0 THEN BVX# = 0 - BSPD#
 BVY# = 0 - BSPD#
 PDEC# = 0
 GOSUB SHOWSPR
 RETURN
 
-REM A linear congruential generator. RND(n) would do this in one token
-REM now; the LCG stays because its sequence is reproducible.
+REM A linear congruential generator, because this dialect has no RND.
 REM The multiply stays inside int64 for any seed under 2^31.
 LABEL RANDOM
 SEED# = MOD(((SEED# * 1103515245) + 12345), 2147483648)
-ROLL# = MOD((SEED# / 65536), RMAX#)
+RND# = MOD((SEED# / 65536), RMAX#)
 RETURN
 
 REM ####################################################################
@@ -634,7 +632,7 @@ NUDGE# = 0
 STALL# = 0
 RMAX# = 4
 GOSUB RANDOM
-BVX# = (ROLL# * 3) - 6
+BVX# = (RND# * 3) - 6
 IF BVX# = 0 THEN BVX# = 3
 RETURN
 
@@ -643,7 +641,7 @@ REM like something with a hand on the paddle rather than a mirror.
 LABEL DEMOAIM
 RMAX# = 81
 GOSUB RANDOM
-DOFF# = ROLL# - 40
+DOFF# = RND# - 40
 RETURN
 
 REM ####################################################################

examples/breakout/sprites/breakout.bas

@@ -241,8 +241,7 @@ 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
-REM inside
+REM inside DRAWPROTOS and left undeclared, they were SHAPE:6 and SHAPE:7 inside
 REM it and empty everywhere else.
 BL$ = ""
 HBL$ = ""
@@ -255,13 +254,10 @@ 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
-REM is
+REM out of the way before anything drawn can be seen. Two rows at the bottom 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
-REM goes
-REM into a layer the frame composites, so nothing here is captured into a
-REM sprite
+REM verbs. Everything this game draws then simply stays there -- a drawing goes
+REM into a layer the frame composites, so nothing here is captured into a sprite
 REM and nothing is redrawn every frame.
 WINDOW 0, 35, 49, 36
 
@@ -297,8 +293,7 @@ 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
-REM dry,
+REM The stamps, once. They used to be rebuilt whenever the SSHAPE pool ran 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
@@ -379,8 +374,7 @@ 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
-REM is
+REM And an eighth the width of the HUD strip, for the same reason: the strip is
 REM rewritten whenever a number in it changes, and the old digits have to go
 REM somewhere first.
 FOR K# = 0 TO 59
@@ -399,8 +393,7 @@ DPLAY# = 1
 DHUD# = 1
 RETURN
 
-REM Take one brick off the screen: stamp the blank over it. Called when a
-REM brick
+REM Take one brick off the screen: stamp the blank over it. Called when a 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
@@ -451,8 +444,7 @@ 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
-REM be
+REM stays, which is the whole point -- so the digits that were there have to be
 REM stamped over before the new ones are drawn.
 Z$ = HBL$
 GSHAPE Z$, 0, 0
@@ -503,10 +495,7 @@ IF SNDON# = 0 THEN VOL 0
 RETURN
 
 LABEL PRESSPAUSE
-IF STATE# <> 2 THEN GOTO PRESSPAUSE2
-STATE# = 6 : GMTYP# = 0 : BAN$ = "PAUSED" : GOSUB SETBANNER
-RETURN
-LABEL PRESSPAUSE2
+IF STATE# = 2 THEN STATE# = 6 : GMTYP# = 0 : BAN$ = "PAUSED" : GOSUB SETBANNER : RETURN
 IF STATE# = 6 THEN STATE# = 2 : BAN$ = "" : GOSUB SETBANNER
 RETURN
 

examples/galaga/enemies.c

@@ -71,15 +71,10 @@ static char *ENEMY_CHARACTER[GALAGA_ENEMY_KINDS] = {
 /* --------------------------------------------------------------- random --- */
 
 /*
- * The engine is this script's source of randomness: it refreshes GAME@.ROLL%
- * each frame and SELF@.ROLL% each call from this PRNG. A hand-rolled LCG
- * rather than rand() so a headless run is the same game on every libc, which
- * 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.
+ * No RND verb exists (issue #16), so the engine is the script's only source
+ * of randomness: it refreshes GAME@.RND% each frame and SELF@.RND% each call
+ * from this PRNG. A hand-rolled LCG rather than rand() so a headless run is
+ * the same game on every libc.
  */
 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@.ROLL% < DT% * 1.5 THEN SELF@.FIRE# = 1
+  IF SELF@.RND% < 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@.ROLL% < DT% * 0.04 THEN SELF@.STATE# = 4 : SELF@.T% = 0
+    IF SELF@.RND% < 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@.ROLL% < DT% * 0.05 THEN SELF@.STATE# = 4 : SELF@.T% = 0
+    IF SELF@.RND% < 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@.ROLL% < DT% * 0.03 THEN SELF@.STATE# = 4 : SELF@.T% = 0
+    IF SELF@.RND% < 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: fresh 0..1 each call; ROLL% in BASIC	*/
+    float    rnd;	/* inbox: engine writes fresh 0..1 each call	*/
 } 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; ROLL% to the script	*/
+    float    rnd;	/* fresh 0..1 each frame; the issue #16 route	*/
 } galaga_Shared;
 
 /* --------------------------------------------------------------- screens --- */

examples/galaga/main.c

@@ -491,8 +491,7 @@ static akerr_ErrorContext *frame(bool *running)
     }
 
     /* The shared frame state, refreshed before any enemy thinks. The engine
-     * 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. */
+     * filling GAME@.RND% is the issue #16 route: no RND verb exists. */
     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,    "ROLL%",    AKBASIC_HOSTFIELD_FLOAT )
+    AKBASIC_HOST_FIELD( galaga_Enemy, rnd,    "RND%",     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,     "ROLL%",    AKBASIC_HOSTFIELD_FLOAT )
+    AKBASIC_HOST_FIELD( galaga_Shared, rnd,     "RND%",     AKBASIC_HOSTFIELD_FLOAT )
 };
 static const akbasic_HostType GAME_TYPE = {
     "GAME", sizeof(galaga_Shared), GAME_FIELDS, 4

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    - it carries chapter 17's LCG rather than the native RND, and seeds it
+REM    - there is no RND, so it carries chapter 17's LCG 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
-ROLL# = 0
+RND# = 0
 TX% = 0
 TB# = 0
 
@@ -816,12 +816,11 @@ REM =====================================================================
 REM  Subroutines.
 REM =====================================================================
 
-REM  Chapter 17's historical generator, verbatim. RND(n) is built in now;
-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.
+REM  Chapter 17's generator, verbatim: there is no RND in this dialect.
+REM  Answers 0 to RMAX#-1 in RND#, from the middle bits of the seed.
 LABEL RANDOM
 SEED# = MOD(((SEED# * 1103515245) + 12345), 2147483648)
-ROLL# = MOD((SEED# / 65536), RMAX#)
+RND# = MOD((SEED# / 65536), RMAX#)
 RETURN
 
 REM  NS# stars in four brightnesses. Two LCG pulls a star, and the
@@ -831,10 +830,10 @@ SI# = 0
 DO WHILE SI# < NS#
   RMAX# = W#
   GOSUB RANDOM
-  X# = ROLL#
+  X# = RND#
   RMAX# = H#
   GOSUB RANDOM
-  Y# = ROLL#
+  Y# = RND#
   B# = MOD(SEED#, 4)
   COLOR 1, STC#(B#)
   DRAW 1, X#, Y#
@@ -1292,7 +1291,7 @@ LABEL REHOME
 MOVSPR L2#, 0.5 * W#, 0.5 * H#
 RMAX# = 360
 GOSUB RANDOM
-SBG#(L2#) = ROLL#
+SBG#(L2#) = RND#
 MOVSPR L2#, SBG#(L2#) # 5
 RETURN
 

include/akbasic/error.h

@@ -12,12 +12,9 @@
  * 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:
  *
- *   - The context behind `IGNORE` became thread-local. `IGNORE` expands at *our*
- *     call site, so our objects reference that storage under whichever model the
- *     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_last_ignored` became thread-local. `IGNORE` expands at *our* call
+ *     site, so our objects reference that symbol under whichever storage model
+ *     the header on the include path declared.
  *   - `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.

src/runtime_disk.c

@@ -407,22 +407,17 @@ 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. This was blocked upstream: listing a
-     * directory needs opendir/readdir, `libakstdlib` did not wrap them, and
-     * this project's rule is that a missing capability gets filed upstream
-     * 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.
+     * Refused rather than half-built. Listing a directory needs opendir/readdir,
+     * which `libakstdlib` does not wrap -- and this project's rule is that a
+     * missing capability gets filed upstream rather than worked around here
+     * (MAINTENANCE.md). Filed as libakstdlib issue #10.
      *
-     * So the blocker is gone and only the work is left. Writing the verb needs
-     * decisions this commit is not the place for: what a listing looks like on
-     * 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.
+     * The alternative was shelling out to `ls`, which a library has no business
+     * doing, or calling readdir directly and stepping outside the error
+     * convention every other call in this file follows.
      */
     FAIL_RETURN(errctx, AKBASIC_ERR_DEVICE,
-		"DIRECTORY is not implemented yet");
+		"DIRECTORY is not implemented: libakstdlib has no directory-reading wrapper yet");
 }
 
 /* ------------------------------------------------------------ BSAVE/BLOAD -- */

tests/disk_verbs.c

@@ -244,16 +244,10 @@ static void test_no_drive_verbs(void)
 	harness_stop();
     }
 
-    /*
-     * 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.
-     */
+    /* DIRECTORY is refused for a different reason, and says which. */
     TEST_REQUIRE_OK(run_program("10 DIRECTORY\n"));
-    TEST_REQUIRE(strstr(HARNESS_OUTPUT, "not implemented") != NULL,
-		 "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);
+    TEST_REQUIRE(strstr(HARNESS_OUTPUT, "libakstdlib") != NULL,
+		 "DIRECTORY should name the missing wrapper, got \"%s\"", HARNESS_OUTPUT);
     harness_stop();
 }