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>
The poll_key half of group E, against the akbasic_InputBackend record. The
libakgl implementation behind it is akgl_controller_poll_key(), which drains a
ring the library fills from SDL events the host pumps -- so the interpreter can
answer "is there a key waiting" without owning an event loop, which is what goal
3 requires.
GET and GETKEY differ in one way and it is the interesting one. GET takes
whatever is there including nothing, and an empty buffer is success with the
empty string rather than an error -- that is what happens on most iterations of
every GET loop ever written, and upstream is explicit that its poll reports it
the same way. GETKEY waits, and since the library may not block, waiting is
spelled as holding the step loop: the verb sets a flag and akbasic_runtime_step()
declines to advance until a key arrives. Every step still returns and a bounded
run() still comes back, so a host keeps its frame rate; the program simply does
not move past the GETKEY.
The PLAY queue is serviced before that check on purpose -- music should keep
playing while a program waits for a keypress. Withdrawing the input device while
a GETKEY is holding releases it rather than wedging the script on a device that
no longer exists.
Both verbs accept an integer variable as well as a string one and give it the raw
key code, which is what a program testing for cursor or function keys needs. No
key is code zero, matching what a C128 reports. A float variable is refused: it
is neither a character nor a code.
SCNCLR goes through the text sink rather than a device, because the sink is where
PRINT already goes and is the only thing that knows what a screen means for this
host. The stdio sink treats it as a no-op; clearing a pipe means nothing.
One thing worth knowing before writing any bounded-run test, and now commented in
tests/input_verbs.c: source lines are stored indexed by line number and the
cursor starts at zero, so a step is spent on each empty slot along the way. A
program at line 10 needs eleven steps before it has run anything.
70/70 ctest, clean under -Wall -Wextra, doxygen clean.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
