Commit Graph

5 Commits

Author SHA1 Message Date
134ade9392 Document the public API in libakgl's Doxygen style
Adds a Doxyfile in the shape libakgl uses -- fifteen deliberate lines, including
WARN_IF_UNDOCUMENTED and WARN_AS_ERROR=FAIL_ON_WARNINGS -- and fills in the 70
public declarations that had no doc block, bringing include/akbasic to 114 of
114.

libakgl is the model rather than libakstdlib. Measured before starting: libakgl
documents 122 of 122 public declarations and libakstdlib 3 of 25, and
libakstdlib's Doxyfile is the unedited doxygen default, PROJECT_NAME = "My
Project" and an empty INPUT. So the house standard is libakgl's, down to the
boilerplate phrasing for the recurring parameters -- "Object to initialize,
inspect, or modify", "Output destination populated by the function", "`NULL` on
success, otherwise an error context owned by the caller".

Worth knowing what the gate actually gates. EXTRACT_ALL=YES suppresses
doxygen's undocumented-entity warnings, so the rule it enforces is that a
*partial* block is an error: document one @param and you must document them all.
Verified by deleting a @param and confirming a non-zero exit, then restoring it.
Full coverage is therefore a convention this commit adopts rather than something
the tool made me do.

Where a contract is non-obvious the block says so rather than restating the
signature: math_plus explains why it alone mutates its left operand, new_unary
notes that hanging the operand on .right is what makes the parser miscount a
negative literal argument, leaf_to_string warns that an assignment renders with
an empty operator, and stop_waiting records that a verb nobody is waiting for is
tolerated. Each cross-references its TODO.md section 6 item.

Also records in TODO.md that this repository has no CI, which libakgl and
libakstdlib both have -- so ctest, the sanitizer build, coverage and this new
doxygen gate are all run by hand today.

ctest 61/61; doxygen Doxyfile exits 0; no warnings under -Wall -Wextra.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-07-31 07:00:16 -04:00
e51b9a1694 Document host/script variable exchange, and file the scope hazard it exposes
The host can expose variables to a BASIC program, in both directions and for
every type, with no marshalling layer -- akbasic_environment_get() finds or
creates by name, the type comes from the suffix as it does for BASIC code, and
host and script share the same akbasic_Value. Nothing new was needed to make
that work.

Testing it before writing it up turned up a hazard worth stating plainly, so the
README documents the pattern and section 6 item 17 records the gap.

Seeding before akbasic_runtime_start() and reading after the script stops is
safe, and so is updating an existing global at any time, because the parent
chain is searched. Creating one mid-run is not, in two ways, and both are
silent. A script suspended part-way through a bounded run() is usually inside a
FOR or GOSUB scope, so a variable created through obj->environment lands in that
scope and dies when it pops -- the script reads it correctly inside the loop and
gets 0 immediately after. And reaching for the root explicitly does not help:
akbasic_environment_get only auto-creates when the environment it is given is
the active one, so with a child active it returns NULL through dest without
raising, and an unchecked host dereferences it.

This one is ours rather than inherited. It falls out of the environment pool
meeting the bounded run(), a combination the reference never had because its
run() never returned.

examples/hostvars.c demonstrates both hazards rather than describing them, and
prints what it observes, so the day this is fixed that output changes and the
example needs revisiting. Like examples/embed.c it is built and run by every
build. Both README snippets were extracted and compiled as a check.

Not fixed here: akbasic_runtime_global() would close it in about fifteen lines,
but what it should do when the script is suspended inside a user function's
scope is a design question worth settling deliberately rather than discovering.
Filed with the proposed signature and the tests it wants.

ctest 61/61; ASan+UBSan 61/61; no warnings under -Wall -Wextra.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-07-31 06:50:55 -04:00
cde6fa8f59 Port the README from the Go version and document embedding
Carries the reference README across, adjusted where C changes the answer: cmake
instead of make, the ak* libraries instead of the go-sdl2 bindings, and the
limits table now includes the three ceilings the Go version did not need because
it called make().

The new "Embedding the interpreter" section is the point of the rewrite, so it
states the four rules the library holds to -- nothing terminates the process,
nothing calls malloc, no file-scope mutable state, the host owns the loop -- and
each was checked against the tree rather than asserted.

Adds akbasic_runtime_load(). Writing the section turned up a real gap: a host
usually already holds its script as a string and wants the sink reserved for
output, and the only path that existed was AKBASIC_MODE_RUNSTREAM reading the
program through the sink's readline, which forces a game to point its output
device at its source text. The alternative was reaching into the header's
"internal API" block for store_line. Neither is something to put in a README.

Adds examples/embed.c, which is the code the README quotes -- a custom sink, a
bounded per-frame run, and the PASS-not-CATCH rule for a loop inside an ATTEMPT.
It is built by every build and registered as a CTest case, so a signature change
breaks the build instead of rotting the document. The README's own snippet is
compiled separately as a check; both were run before committing.

The "What Isn't Implemented / Isn't Working" section leads with the eleven
inherited defects rather than burying them, because five of them were found by
this port and a reader deserves to know that 1 - 2 - 3 computes 1 - 2 before
they hit it. Corrected two claims while verifying: the runtime is 10.1MB rather
than the ~8MB first written, and its largest single cost is the environment pool
at 4.1MB, not the source table.

ctest 60/60; ASan+UBSan 60/60; no warnings under -Wall -Wextra.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-07-31 06:42:08 -04:00
7531df57ec Bump libakgl and libakstdlib to pick up the filed issues
Both bumps are TODO.md only -- no code, no headers, no build files -- so nothing
akbasic links against changed and the suite is unaffected.

libakgl 6dfe748 -> 5f03475 records the four API gaps blocking this port: text
measurement (which blocks the akgl text sink outright), immediate-mode drawing,
audio, and a non-blocking keystroke read.

libakstdlib 95e5002 -> fd71bcc records what this port had to work around,
including the measurement that akbasic makes 10 calls into that library against
116 to raw libc.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-07-31 06:32:42 -04:00
f8c15c2f2c Port the BASIC interpreter from Go to C
Reproduces deps/basicinterpret in C, in the idiom of the ak* libraries. All 41
.bas files in the reference's corpus produce byte-identical stdout, including
the trailing double newline on an error line -- that comes from basicError
building a string ending in \n and handing it to Println, and
array_outofbounds.txt encodes it.

The corpus is driven in place from the submodule as 41 individual CTest cases
rather than copied, so it cannot drift from upstream. Eighteen unit tests cover
what the corpus cannot reach.

Three structural changes carry most of the work. Go's three reflection lookups
(Command*, Function*, ParseCommand*) become one sorted dispatch table in
src/verbs.c searched with bsearch; adding a verb is a row and two functions. The
five Go maps become one fixed open-addressed table over aksl_strhash_djb2. And
run(), which owned the process until MODE_QUIT, splits into step() plus a
bounded run() -- goal 3 requires a host game to be able to bound execution, and
nothing in the library now terminates the process or touches SDL.

Output goes through an akbasic_TextSink vtable. src/sink_stdio.c is what makes
the corpus runnable with no SDL present; the akgl-backed sink is still to come
and is blocked on libakgl having no text-measurement call.

src/convert.c exists because libakstdlib's aksl_ato* family cannot report a
conversion failure (its TODO.md 2.1.5). The reference checks strconv's error at
four sites and turns it into a BASIC error; routing those through aksl_atoi
would have turned four diagnosable errors into wrong answers, with VAL("garbage")
quietly returning 0. TODO.md 1.9 records which libakstdlib calls are cleared for
use here and which are not.

Reference defects are reproduced, not fixed: the golden files encode the observed
behaviour and a silent correction is a behaviour change. TODO.md section 6 lists
sixteen, and tests/known_reference_defects.c asserts the *correct* contract for
six of them under AKBASIC_KNOWN_FAILING_TESTS, so a fix shows up as
"unexpectedly passed". Five of the sixteen were found by this port and are new:
subtraction stops after one operator so 1-2-3 computes 1-2 and abandons the rest
of the line (a wrong answer, not a refused one); a unary-minus argument inflates
a function's arity so ABS(-9) is rejected; a comparison operator in a line's
final column is dropped; hex literals never survive the scanner; and the
"Reserved word in variable name" check is dead code.

Where the reference reaches undefined behaviour by a route that is defined in Go
-- an out-of-range shift, a negative string multiplier, integer division by zero
-- this raises instead of inheriting the UB. No golden case exercises any of
them.

The top-level CMakeLists shadows add_test, set_tests_properties and
add_custom_target around all three add_subdirectory calls. Without it libakerror's
tests land in our suite as Not Run, and its un-namespaced `coverage` target stops
a coverage build from configuring at all. Test targets are akbasic_test_<name>:
bare test_<name> collides with libakstdlib's, which is what broke libakgl's
configure in c2b16d3.

ctest 59/59; ASan+UBSan 59/59; 92.3% line and 96.9% function coverage; no
warnings under -Wall -Wextra. Branch coverage is not a target, for the reason
libakstdlib and libakgl both record: the akerror macros expand into large branch
trees at every call site.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-07-30 23:53:56 -04:00