9 Commits

Author	SHA1	Message	Date
Andrew Kesterson	1fb808f480	Rewrite the two game tutorials as instructions rather than commentary ... Chapters 17 and 18 read as a code review of a finished listing: they explained why each decision had been made, walked through the project's own history, and led with what had once been broken. A reader who wanted to build the game got the reasoning and had to reconstruct the program. Both are now step-by-step. Each opens with a picture of the finished game and a bullet list of the steps, each bullet is a section, and each section states its goal, shows the code, and says how to check it. Chapter 17 is sixteen steps and Chapter 18 is thirteen, and the last of each is the assembly: the order of the file, the full declaration block, and the routines the earlier steps referred to. Project history is gone -- it belongs in Chapter 14 and in git -- and where a listing has to do something awkward, the tutorial shows how first and names the `TODO.md` item that will make it unnecessary second. **Three defects had no entry anywhere**, which the rewrite found by trying to state each rule as a rule. §6 item 35: `a - b + c` computes `a - (b + c)`, because `subtraction()` sits above `addition()` as its own precedence level and the inner loop eats the `+`. Item 36: only one unparenthesised `AND` or `OR` is matched, which is item 12's `if`-where-`while` on the one operator pair item 12 did not reach. Item 37: a `GOTO` out of a `FOR` or a `DO` leaks the loop's scope, so a main loop written that way stops on the thirty-second lost life -- which is why both games are built out of `LABEL` and `GOTO`, and it is a workaround rather than a preference. Chapter 3 gains the identifier rule the third trial ran into: there is no underscore in a name, and the error says `UNKNOWN TOKEN _`. **`tools/screenshot.c` learned to draw the text layer**, behind a new `text=1` fence attribute, because Chapter 17's game is characters in the grid and a figure without that layer is two sprites on black. It opens the bundled font at the size the standalone frontend uses, so a figure's cell size is the reader's cell size, and it uses the akgl sink alone rather than a tee so the program's output lands in the picture instead of on the stdout the caller reads to decide a figure failed. Both new figures -- `breakout-game.png` and `breakout-game-artwork.png` -- are generated from listings in the chapters like every other one. Verified by handing each chapter, alone, to an agent on a much smaller model and telling it to build the game from the tutorial text with the `examples/` tree off limits. The first pass scored 3.5 and 3 out of 10 and named what was missing: routines referred to but never shown, the third level layout, the sprite `DATA`, the font table, edits to earlier routines that were never marked as edits. Those are now in. The second pass built a 658-line Chapter 17 game that plays itself for ninety seconds with the score at 1890 and no error line, and the third built a 1053-line Chapter 18 game with 61 labels, no invented routines, no gaps found, and forty seconds clean. 9/10 and 8/10. One real bug in the new prose, caught in review: Chapter 18's `HITBAR` did not set the `HIT#` that `BALLPADDLE` reads to decide whether the paddle already caught the ball. Both suites green in both configurations, `docs_examples` and `docs_screenshots --check` pass. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01EwxGB6TdoVvZ11KQQME9cL	2026-08-02 08:08:23 -04:00
Andrew Kesterson	812d846e47	Take libakgl 0.7.0, and refuse an over-long type or field name ... 0.6.0 and 0.7.0 break 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 so it can drop the exit-status trap its own suites needed. That is the same defect include/akbasic/error.h guards for this band, now fixed at the source rather than worked around in two places. The floor moves to 0.7.0 anyway. The soname carries MAJOR.MINOR while the major is 0, so deciding for ourselves which of libakgl's minor releases were really compatible is exactly the judgement it exists to take away. 0.7.0 is largely about a defect class worth checking for here rather than assuming past: ten unterminated strncpy calls into fixed-width name fields. Ours are clean -- every one is bounded to size - 1 and every buffer is either explicitly terminated afterwards or memset first, checked site by site. But two of them, both written last week in src/structtype.c, truncated an over-long name silently, and truncation is an error everywhere else in this interpreter. It matters more for a name than for a value: two long type names trimmed to the same 31 characters collide, and the second is then reported as redeclaring a type the program never wrote. Both are refused now, showing the name as written. The check was unreachable as first drafted, because the prescan read words into a buffer the size of the limit and so trimmed them before anything could look -- the scratch is twice the limit now, which is what makes the two cases distinguishable at all. tests/struct_types.c pins that it stays reachable. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>	2026-08-01 13:30:35 -04:00
Andrew Kesterson	6bac929901	Document structures: a chapter, the architecture, and the differences ... docs/16-structures.md is the feature: records, nesting, copy-on-assign, strict pointers, lists, what is checked and what is not, and how a host shares its own C structs. Every example in it is executed by docs_examples and byte-compared, including the refusals -- so a message that changes fails the suite rather than quietly making the chapter wrong. The chapter makes one contrast explicitly, because it is the question a reader will actually have: a misspelled *field* is refused and a misspelled *variable* still prints zero. The rule underneath is that what the program declared gets checked and what it did not gets shrugged at -- a variable's name is never declared, a TYPE's field list is. Structures end up the strictest thing in the language, not from a higher standard but because they are the only named thing whose valid spellings are written down. Chapter 14 gains the layout: an instance is a contiguous run of value slots with a diagram of where the fields sit, the three-pass prescan and why each pass exists, why the copy cannot live in akbasic_value_clone(), and why the render depth bound is four rather than eight. Chapter 3 gains the @ suffix, chapter 13 records that all of this is an addition BASIC 7.0 has nothing like, and the verb reference gains TYPE, POINT and DIM ... AS. MAINTENANCE.md gains the two rules that are on a maintainer rather than on a test: a structure copy must not go through clone, and a field chain gets its own leaf field. TODO.md section 5 records what was invented and the three limits that are ours, and section 8 records the two defects the work exposed. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>	2026-08-01 12:03:02 -04:00
Andrew Kesterson	3415c9aec6	Take libakgl 0.5.0 and rename every symbol it namespaced ... 0.5.0 gives every exported symbol the akgl_ prefix, which is the first libakgl release to break this project's source rather than only its ABI. The soname goes to libakgl.so.0.5 and include/akbasic/akgl.h asserts the floor. What moved here: akgl_render_bind2d is akgl_render_2d_bind, akgl_sprite_sheet_coords_for_frame is akgl_spritesheet_coords_for_frame, the renderer, camera and window globals carry the prefix, and _akgl_renderer and _akgl_camera are akgl_default_renderer and akgl_default_camera. The renames were applied by site rather than by pattern, because renderer is also a parameter name in src/sprite_akgl.c and a struct member throughout src/frontend_akgl.c -- a substitution would have rewritten both without a word. That is the same trap upstream describes hitting, and it is worth knowing that the defect behind the rename was not cosmetic: an exported global called renderer collided with a test's own variable, the executable's definition preempted the library's, and every texture load in that suite failed while the suite passed. 0.5.0 also fixes libakgl defect 26, which was one of the two reasons src/sprite_akgl.c installs its own renderfunc: akgl_actor_render took its destination height from the sprite's width, drawing a 24x21 Commodore sprite as a 24x24 square. The renderfunc stays, because the other reason has not moved -- an actor carries one scalar scale and SPRITE has separate x- and y-expand bits -- but the comments and TODO.md deviation 40 no longer claim a defect that is fixed. Every documentation figure re-renders byte-identical under the new library, which is what says the sprite and drawing paths did not move underneath them. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>	2026-08-01 08:01:43 -04:00
Andrew Kesterson	8077806598	Take libakerror 2.0.1, and guard the exit status it fixes ... 2.0.0 makes the error pool and the status registry thread safe, and it is an ABI break carrying the soname to libakerror.so.2. The break is a quiet one: __akerr_last_ignored became thread-local and akerr_next_error() now returns a context that already holds a reference, so objects compiled against a 1.x header and linked against 2.x count every reference twice and never give a slot back. Nothing about that fails to link, which is exactly what a guard is for -- include/akbasic/error.h feature-tests AKERR_THREAD_SAFE instead of AKERR_FIRST_CONSUMER_STATUS, which 2.0.0 also still defines and which therefore no longer distinguishes anything. 2.0.1 is the release this band needed most. The default unhandled-error handler ended in exit(errctx->status), and a process exit status is one byte: AKBASIC_ERR_BASE is 512, and 512 truncates to 0, so an unhandled AKBASIC_ERR_SYNTAX reported success to anything watching $?. Every other code in the band came out as some unrelated error's number. akerr_exit() substitutes 125 for anything a byte cannot carry, and a probe raising AKBASIC_ERR_DEVICE through FINISH_NORETURN now exits 125 rather than 7. It was latent here rather than live -- src/main.c handles the context and returns EXIT_FAILURE, and every test with a top-level ATTEMPT carries a HANDLE_DEFAULT -- but "no caller relies on it today" is not a property a header can keep true. tests/version_check.c asserts the mapping and fails if AKBASIC_ERR_BASE ever stops truncating to zero, because that is the day this stops being about our base. Chapter 10 gains a threading section: libakerror is safe from any thread now, and this interpreter is not and has no lock anywhere in it. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>	2026-08-01 08:00:24 -04:00
Andrew Kesterson	16b38c1138	Generate the documentation's figures from the listings they illustrate ... Chapters 6 and 8 described what a verb draws in prose. Eight figures now show it, and each one is produced by running the BASIC listing printed immediately above it -- so a picture cannot drift away from the code beside it, which is the way a screenshot goes wrong and the way nothing notices. tools/screenshot.c is a second SDL host, much smaller than the frontend: dummy video driver, software renderer, run to completion, read the target back, write a PNG. It draws no text layer on purpose, so a READY in the corner is not noise in a figure about BOX and no font has to be resolved. tools/docs_screenshots.sh reads the new screenshot=NAME fence tag straight out of the markdown. size=WxH is the second tag, and SCALE's figure uses it: the point being made is a 320x200 listing filling a larger window, which cannot be made on a 320x200 surface. Two gates, answering different questions. docs_examples fails a tagged block with no image, in both configurations, so a figure cannot be added and forgotten. docs_screenshots -- a CTest, AKGL build only -- re-renders every figure and compares byte for byte, so a listing edited without regenerating fails. Only the second catches a stale picture. The PNGs are checked in because a reader on the forge has no build tree, and docs/images/README.md says loudly that they are generated. Regenerating is never part of a build: the target is run deliberately, so a make cannot put eight binary diffs in front of whoever ran it. Drawing the BOX figure caught a defect in TODO.md itself. Deviation 16 claimed in bold that BOX fills on a negative angle while its own paragraph said the fill was filed rather than implemented. BOX cannot fill, and filled_rect is reached by no verb as a result. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>	2026-08-01 07:37:04 -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	342e4c07da	Execute every documented example as a test ... docs/ and README.md carry 85 fenced blocks. Every one was checked by hand exactly once, when it was written, which is not a standard that survives a changing interpreter -- and four were already wrong: two transcripts showing a leading space PRINT does not emit, akbasic_TextSink in README.md missing the two members it had grown hours earlier, and FILTER's refusal quoted with wording the code does not use. tests/docs_examples.sh reads a fence-tag vocabulary and runs what it finds. BASIC programs and transcripts run and are byte-compared against an `output` block; C snippets compile with -fsyntax-only against the real include path, which CMake writes out because it is transitive through akerror, akstdlib and akgl; shell blocks run in a sandbox. Anything that would reconfigure the build tree, hit the network or re-enter the suite is tagged norun with the reason in MAINTENANCE.md, and the two cmake blocks stay hand-maintained by decision. An untagged block is a failure rather than a default, and the pass line reports what it executed by kind. Both exist because the way a harness like this dies is by quietly matching nothing and passing -- which it duly did on the first CTest run, where a generator expression evaluating to nothing still contributed an empty argument that the script read as a filename. The count is what caught it. The excerpt check earns its own mention: a block tagged `c excerpt=include/akbasic/sink.h` must still appear in that header, comments and whitespace ignored. Compiling it would only redefine the type, so a compile check could not have found the stale struct, and did not. Registered as the CTest case docs_examples in both configurations. Fixing the four wrong examples turned up two interpreter defects, fixed in the previous commit and recorded in TODO.md section 8. MAINTENANCE.md is new: the fence-tag reference, what to do when the case fails, and the conventions that until now only existed inside source comments -- the three test lists and how two of them invert "passed", the sorted verb table, that a golden file is never edited to suit this interpreter, and that a fix gets mutation-checked with a file copy rather than git checkout. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>	2026-07-31 22:41:36 -04:00