10 Commits

Author	SHA1	Message	Date
Andrew Kesterson	737fdc760f	Document every error code a script can see, as chapter 15 ... ER# held numbers nothing explained. The appendix lists the four error classes the interpreter prints, the eight codes it owns and what raises each, and the codes that reach ER# from errno, libakerror and libakgl underneath it. The table is not asserted. A program in the chapter trips seven of the eight and prints what it got, and docs_examples byte-compares the result -- so the numbers are checked rather than claimed. The eighth, 516, is not usefully trappable and the chapter says why: entering a handler takes a scope, and the pool being empty is what raised it. Two things worth a reader's attention came out of writing it. Two codes register the same ERR() text, so a program must compare the number and print the text. And VAL reports libakerror's Value Error rather than the interpreter's 517, which makes that number the platform's rather than ours -- filed as section 6 item 21, not fixed here, because deciding which libakstdlib failures to translate is a boundary question and ENOENT out of DOPEN is the counter-case. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>	2026-08-01 07:36:36 -04:00
Andrew Kesterson	23ccb66f69	Document the interpreter's architecture as chapter fourteen ... Chapters 1 through 13 describe the language. Nothing described the machine that runs it, and the answers were spread across header comments, TODO.md sections written for a different purpose, and the source itself. Somebody embedding the interpreter, debugging something it did, or adding a verb had to reconstruct the shape from all three. docs/14-architecture.md is that shape, and only that: the three targets and the driver, the single akbasic_Runtime and why nothing is file-scope, akbasic_runtime_step() unrolled with the reason each stage sits where it does, the four modes and what set_mode() does beyond assigning, a line's journey from text through tokens and leaves to a verb handler, the dispatch table, the pool map with what each exhaustion actually says, environments doubling as block state, the two kinds of error, devices, and interrupts. It defers rather than restates. The headers are the authority on every function's contract and the chapter says so up front; where a rule is subtle the header comment already states it at more length than a chapter should. MAINTENANCE.md keeps the conventions and now points here for the mechanism, so there is still one copy of each. Two sections are the reason it exists at all. Debugging: reading a TRON trace as evidence about the loop rather than the lines, reading an akerror stack trace and what it is not, four breakpoints and the expressions worth printing at them, narrowing with ctest -R and the mock devices, and a symptom-to-cause table. Changing it: the verb recipe end to end including the private src/verbs.h prototype that is easy to miss, the rule that a missing dependency capability gets filed upstream rather than worked around, and the five constraints goal 3 puts on any change. A `text` fence tag comes with it. Every fenced block in docs/ is executed and an untagged one is a hard error, so six block diagrams had nowhere to live. The tag means never executed, it is counted in the skip line like `cmake`, and MAINTENANCE.md documents it -- the alternative was an indented block the extractor never sees, and a picture nobody decided about is indistinguishable from a test nobody ran. tests/docs_examples.sh now makes --root and --basic absolute before it starts. Both are used from inside a sandbox directory it cd's into, so the invocation MAINTENANCE.md itself documents -- --root . --basic ./build/basic -- failed every example with "exited 127" and every setup= with "setup failed". CTest passes absolute paths and never saw it; running one document by hand hits it immediately. Writing the error section turned up a defect and TODO.md section 8 records it. The ATTEMPT blocks that turn a script's mistake into an error line wrap parsing and interpretation but not scanning, so a line with more than 32 tokens escapes as an interpreter error: stack trace, exit 1, and at a prompt the REPL is gone. That is the same shape as section 8 item 2, on a path that fix did not cover. Not fixed here -- it is a behaviour change and wants its own tests -- but written down with the three call sites and what would cover them. Both configurations stay green: 95/95 and 94/94. docs_examples now runs 37 programs, 9 transcripts, 45 output comparisons, 3 C snippets, 2 excerpts and 2 shell blocks, and skips 9 text blocks. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>	2026-07-31 23:14:17 -04:00
Andrew Kesterson	80b76ad467	Split the documentation by who reads it ... README.md was 577 lines and answered four different questions at once: what the project is, how to build it, every verb and function in the language, and how to maintain the test harness. The verb and function lists had already been written a second time in docs/11 and docs/12, which is how a list of that size goes stale -- there is no way to notice the two have drifted apart. README.md is now 150 lines and holds only what somebody evaluating the project needs: what it is, the quickstart, why it was rewritten in C, the five rules embedding imposes on the design, the two ways to use it, and where everything else lives. Technical detail goes to docs/, maintenance to MAINTENANCE.md. The akbasic_TextSink struct moved to docs/10-embedding.md rather than being deleted. It was the corpus's only `c excerpt=` block -- the check that caught the stale struct two commits ago -- so dropping it with the README would have quietly retired a test. docs/10 also stopped claiming README.md carries the full API surface and the pool limits, which the trim made false. CLAUDE.md went from 458 lines to 62, because almost none of it was agent-specific. The project goals, the Go reference and its architecture, the dependency version and ABI rules, the four ways an embedded build collides, the libakerror convention, the error-code range map and the style rules are all things a maintainer needs, and they are now in MAINTENANCE.md with one copy to keep true. CLAUDE.md points there and keeps only the rules no test enforces: tests in the same commit asserting the correct contract, file a missing dependency capability upstream, do not edit generated output or tests/reference/, co-author your commits. Four claims did not survive the move, having gone stale where nothing could notice: - "The repository is currently empty apart from its submodules -- no commits, no source tree, no build files." There are 43 commits. - libakgl's target_compile_definitions(akerror PUBLIC AKERR_MAX_ERR_VALUE) at deps/libakgl/CMakeLists.txt:44, described as inert but present. It is gone; only a historical mention in a comment remains. - "akbasic_init() claims 512-767." There is no akbasic_init. It is akbasic_error_register(), called from akbasic_runtime_init(). - Time-relative phrasing ("libakgl hit two of them in the last week"). Five places pointed at CLAUDE.md for the range map or the file-it-upstream rule and now point at MAINTENANCE.md: include/akbasic/error.h, src/runtime_disk.c and three entries in TODO.md. Both source changes are comments. deps/libakgl/TODO.md cites it too and is left alone; it is a submodule, and the rule it quotes is still reachable from CLAUDE.md. ctest is green at 95 of 95, docs_examples included: 36 programs, 9 transcripts, 44 output comparisons, 3 C snippets, 1 excerpt. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>	2026-07-31 22:59:43 -04:00
Andrew Kesterson	9845e77a5c	Finish the language: every remaining verb group, and the defects that blocked them ... Closes groups A, C, D, E, F, H and J of TODO.md section 4, plus RESTORE and RENUMBER, and closes section 6 -- all seventeen reference defects. Seven of those turned out to have been fixed or never ported and nobody had written it down; the audit records the evidence for each. Two of the seventeen were real. math_plus mutated its left operand when the operand was mutable, so A# + 1 could modify A#; it was gated on FOR/NEXT coverage because NEXT relied on the mutation, so tests/for_next.c came first and NEXT now writes the counter back itself. And the binary operators summed both numeric fields of their right operand, which no BASIC program can reach -- that one needed a test written against the value API. Writing the tests turned up eight defects nobody had listed. Seven are fixed: IF A = 2 THEN was a parse error; only == worked IF ... AND ... was a parse error, because a condition parsed as one relation IF A = 1 OR B = 2 THEN was silently always false, and so was IF A THEN EXIT before any NEXT restarted the program and exhausted the variable pool READ never found a DATA line above it, and swallowed the lines between PRINT 2 + 2 at the prompt was filed as program text instead of answering a short read discarded its bytes, so COPY produced empty files every verb taking an argument list said "peek() returned nil token!" on none The eighth is not fixed and cannot be quietly: a FOR whose step overshoots runs its body one extra time, and FOR I = 1 TO 1 runs it zero times. The two errors cancel for a step of 1, which is why neither was noticed. Correcting them changes the expected output of a checked-in acceptance file, and tests/reference/README.md forbids editing one to suit this interpreter. It is tests/for_semantics.c in AKBASIC_KNOWN_FAILING_TESTS, asserting the correct contract, and TODO.md items 19 and 20. Sprites are real libakgl actors with a renderfunc of their own, because akgl_actor_render draws every sprite square and an actor has no per-axis scale. Both are filed upstream. SPRSAV takes an image file, an SSHAPE handle or a 63-element integer array -- a string here cannot hold a zero byte. Verbs that need hardware that does not exist are refused by name with the reason rather than faked: SYS, HEADER, COLLECT, BACKUP, BOOT, FILTER, and DIRECTORY, which is refused for a missing libakstdlib wrapper filed upstream. 94 tests in the default build, 93 with SDL, 94 under ASan and UBSan, doxygen clean. The Go acceptance corpus stayed green throughout. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>	2026-07-31 21:50:37 -04:00
Andrew Kesterson	cfdde907df	Type at the window with a real keyboard: the akgl_typing test ... xdotool closes the gap that shipped the missing SDL_StartTextInput(). Every other keyboard test synthesises SDL events, which covers the code downstream of SDL and cannot cover the code upstream of it -- so the suite stayed green while the real keyboard was dead. akgl_typing starts the driver under a pty, waits for the window with xdotool search --sync, gives it focus, and types a program containing a string literal and a lower-case one, polling the mirrored stdout for what they print. Verified by reverting both halves of the text-input fix and watching it fail with the reported symptom: READY, and nothing after it. Skips rather than fails without a display, xdotool, script(1) or a window manager -- none of those means the answer is no. It steals keyboard focus for about fifteen seconds; AKBASIC_SKIP_INTERACTIVE=1 skips it deliberately. xdotool and script(1) are documented as optional test dependencies, alongside what gcovr and python3 already bought. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>	2026-07-31 14:35:07 -04:00
Andrew Kesterson	fca9ad4a89	Consume libakgl 0.3.0: every workaround deleted, two capabilities gained ... 0.3.0 closed all ten API gaps this port had filed. The four workarounds go with them: the CMake block that declared libakgl's vendored dependencies by hand, the akgl/actor.h include in three files, and the six vtable pointers assigned by hand in two more, now akgl_render_bind2d(). Two gaps were capabilities rather than inconveniences, and both are now real: The line editor takes the composed UTF-8 text the ring carries in preference to the keycode, so shifted characters, keyboard layouts, compose keys and dead keys all work. A double quote can be typed, which means a BASIC string literal can be typed -- the sharp end of the old limitation. Letters are no longer folded to upper case. SOUND's dir/min/step reach akgl_audio_sweep instead of being refused. dir 3 sweeps once rather than oscillating and TODO.md section 5 says so. A backend with no sweep still refuses the swept note and plays the held one. The adaptors now carry an AKGL_VERSION_AT_LEAST(0, 3, 0) floor, verified by temporarily demanding 0.4.0 and watching it fire. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>	2026-07-31 13:25:14 -04:00
Andrew Kesterson	583c0abbd2	Retire the byte-for-byte fidelity constraint, and fix what it was blocking ... The Go reference is deprecated and will not be updated, so the two projects are no longer required to match. Recorded as TODO.md section 0.1, first thing in the file, because it silently reverses the premise several later sections were written on -- an agent reading section 6 without it will park work that is no longer blocked. Section 6 item 16 was the item waiting on exactly this and is now fixed: the keyword tables are searched on the base name with any type suffix stripped, so PRINT$, LEN# and GOTO% are refused as variable names and the reference's own diagnostic stops being dead code. It cost the one golden case predicted, and the cost was nothing -- renaming a variable in strreverse.bas left its expected output byte-for-byte unchanged. AKBASIC_KNOWN_FAILING_TESTS is empty as a result and known_reference_defects.c is gone. Section 6 items 1-9 and 11 are reopened as an ordinary defect list. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>	2026-07-31 12:52:00 -04:00
Andrew Kesterson	eb5374d212	Check the reference corpus in, so the build stops needing the Go submodule ... All 41 .bas/.txt pairs copied byte for byte from basicinterpreter@d76162c into tests/reference/, plus the Commodore font into assets/fonts/ -- the two things that tied the build to deps/basicinterpret. Both were verified cmp-identical to the submodule copies. This reverses a decision that was deliberate and correct at the time: the corpus was driven in place because copying a submodule's corpus guarantees drift. Overruled on purpose -- the Go dependency is being deprecated, and a build that cannot run its acceptance suite without cloning the implementation it replaced is not finished. tests/reference/README.md records what the drift now costs and that those expectations are never edited. Checked rather than assumed: both configurations configure, build and pass from scratch with deps/basicinterpret moved out of the tree entirely. The submodule is kept as the behavioural spec, which is a real use. The font came with an open licence question; assets/fonts/PROVENANCE.md states it. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>	2026-07-31 12:35:40 -04:00
Andrew Kesterson	c70f8e7727	Update the dependency table to libakstdlib and libakgl 0.2.0 ... Both are at 0.2.0 with libakstdlib.so.0.2 and libakgl.so.0.2 sonames. Records that they have to be bumped as a pair -- libakgl 0.2.0 consumes the libakstdlib 0.2.0 API, so a tree pinning libakstdlib at 0.1.0 while adding libakgl by add_subdirectory() compiles 0.2.0-era code against 0.1.0 headers and fails. Also rewrites the paragraph that told an agent to read libakstdlib's TODO.md section 2.1 before touching akstdlib.h. That release fixed all six confirmed defects, folded the four known-failing tests back in and left AKSL_KNOWN_FAILING_TESTS empty, so the warning now points at a list that is empty and the bans it implied would send somebody around a workaround for functions that work. The one caveat that survives -- aksl_strhash_djb2 still sign-extends char -- is named, along with the section explaining why the symbol tables cannot reach it. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>	2026-07-31 09:55:47 -04:00
Andrew Kesterson	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