andrew/akbasic
1
0
Fork 0
Code Issues 28 Pull Requests 1 Actions Packages Projects Releases Wiki Activity
Files
7c1bee431aa41d734f729b2a5f81b9201ba57b54
akbasic/src/environment.c

415 lines
15 KiB
C
Raw Normal View History

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> Co-Authored-By: Andrew Kesterson <andrew@aklabs.net>
2026-07-30 23:53:56 -04:00
/**
* @file environment.c
* @brief Implements the scope and per-line working state.
*/
#include <inttypes.h>
#include <string.h>
#include <akerror.h>
#include <akbasic/environment.h>
#include <akbasic/error.h>
#include <akbasic/runtime.h>
akerr_ErrorContext *akbasic_environment_init(akbasic_Environment *obj, akbasic_Runtime *runtime, akbasic_Environment *parent)
{
PREPARE_ERROR(errctx);
FAIL_ZERO_RETURN(errctx, (obj != NULL), AKERR_NULLPOINTER, "NULL environment in init");
FAIL_ZERO_RETURN(errctx, (runtime != NULL), AKERR_NULLPOINTER, "NULL runtime in environment init");
PASS(errctx, akbasic_symtab_init(&obj->variables, AKBASIC_MAX_VARIABLES));
PASS(errctx, akbasic_symtab_init(&obj->functions, AKBASIC_MAX_FUNCTIONS));
PASS(errctx, akbasic_symtab_init(&obj->labels, AKBASIC_MAX_LABELS));
obj->parent = parent;
obj->runtime = runtime;
obj->forNextVariable = NULL;
obj->forStepLeaf = NULL;
obj->forToLeaf = NULL;
obj->loopFirstLine = 0;
obj->loopExitLine = 0;
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> Co-Authored-By: Andrew Kesterson <andrew@aklabs.net>
2026-07-31 21:50:37 -04:00
obj->exiting = false;
obj->doConditionLeaf = NULL;
obj->doConditionKind = AKBASIC_LOOPCOND_NONE;
obj->isDoLoop = false;
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> Co-Authored-By: Andrew Kesterson <andrew@aklabs.net>
2026-07-30 23:53:56 -04:00
obj->gosubReturnLine = 0;
obj->readReturnLine = 0;
obj->readIdentifierIdx = 0;
obj->waitingForCommand[0] = '\0';
obj->errorToken = NULL;
memset(obj->readIdentifierLeaves, 0, sizeof(obj->readIdentifierLeaves));
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> Co-Authored-By: Andrew Kesterson <andrew@aklabs.net>
2026-07-31 21:50:37 -04:00
obj->doLeafPool.next = 0;
obj->doLeafPool.capacity = AKBASIC_MAX_CONDITION_LEAVES;
obj->doLeafPool.leaves = obj->doLeafStorage;
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> Co-Authored-By: Andrew Kesterson <andrew@aklabs.net>
2026-07-30 23:53:56 -04:00
obj->readLeafPool.next = 0;
obj->readLeafPool.capacity = AKBASIC_MAX_LEAVES;
obj->readLeafPool.leaves = obj->readLeafStorage;
PASS(errctx, akbasic_value_zero(&obj->forStepValue));
PASS(errctx, akbasic_value_zero(&obj->forToValue));
PASS(errctx, akbasic_value_zero(&obj->returnValue));
if ( obj->parent != NULL ) {
obj->lineno = obj->parent->lineno;
obj->nextline = obj->parent->nextline;
} else {
obj->lineno = 0;
obj->nextline = 0;
}
obj->nextvalue = 0;
PASS(errctx, akbasic_environment_zero_parser(obj));
SUCCEED_RETURN(errctx);
}
akerr_ErrorContext *akbasic_environment_zero(akbasic_Environment *obj)
{
PREPARE_ERROR(errctx);
int i = 0;
FAIL_ZERO_RETURN(errctx, (obj != NULL), AKERR_NULLPOINTER, "NULL environment in zero");
for ( i = 0; i < AKBASIC_MAX_VALUES; i++ ) {
PASS(errctx, akbasic_value_init(&obj->values[i]));
}
obj->nextvalue = 0;
SUCCEED_RETURN(errctx);
}
akerr_ErrorContext *akbasic_environment_zero_parser(akbasic_Environment *obj)
{
PREPARE_ERROR(errctx);
int i = 0;
FAIL_ZERO_RETURN(errctx, (obj != NULL), AKERR_NULLPOINTER, "NULL environment in zero_parser");
for ( i = 0; i < AKBASIC_MAX_LEAVES; i++ ) {
PASS(errctx, akbasic_leaf_init(&obj->leaves[i], AKBASIC_LEAF_UNDEFINED));
}
for ( i = 0; i < AKBASIC_MAX_TOKENS; i++ ) {
PASS(errctx, akbasic_token_init(&obj->tokens[i]));
}
obj->curtoken = 0;
obj->nexttoken = 0;
obj->nextleaf = 0;
SUCCEED_RETURN(errctx);
}
akerr_ErrorContext *akbasic_environment_new_value(akbasic_Environment *obj, akbasic_Value **dest)
{
PREPARE_ERROR(errctx);
FAIL_ZERO_RETURN(errctx, (obj != NULL && dest != NULL), AKERR_NULLPOINTER,
"NULL argument in new_value");
FAIL_ZERO_RETURN(errctx, (obj->nextvalue < AKBASIC_MAX_VALUES), AKBASIC_ERR_BOUNDS,
"Maximum values per line reached");
*dest = &obj->values[obj->nextvalue];
obj->nextvalue += 1;
SUCCEED_RETURN(errctx);
}
akerr_ErrorContext *akbasic_environment_new_leaf(akbasic_Environment *obj, akbasic_ASTLeaf **dest)
{
PREPARE_ERROR(errctx);
FAIL_ZERO_RETURN(errctx, (obj != NULL && dest != NULL), AKERR_NULLPOINTER,
"NULL argument in new_leaf");
FAIL_ZERO_RETURN(errctx, (obj->nextleaf < AKBASIC_MAX_LEAVES), AKBASIC_ERR_BOUNDS,
"No more leaves available");
*dest = &obj->leaves[obj->nextleaf];
obj->nextleaf += 1;
SUCCEED_RETURN(errctx);
}
akerr_ErrorContext *akbasic_environment_wait_for_command(akbasic_Environment *obj, const char *command)
{
PREPARE_ERROR(errctx);
FAIL_ZERO_RETURN(errctx, (obj != NULL && command != NULL), AKERR_NULLPOINTER,
"NULL argument in wait_for_command");
/*
* The reference panics here. An interpreter library may not take the process
* with it, so this raises instead -- but it is still a hard failure, because
* two pending waits in one environment means the block structure is already
* corrupt.
*/
FAIL_NONZERO_RETURN(errctx, (obj->waitingForCommand[0] != '\0'), AKBASIC_ERR_STATE,
"Can't wait on multiple commands in the same environment : %s",
obj->waitingForCommand);
FAIL_ZERO_RETURN(errctx, (strlen(command) < sizeof(obj->waitingForCommand)),
AKBASIC_ERR_BOUNDS, "Command name '%s' is too long to wait on", command);
strncpy(obj->waitingForCommand, command, sizeof(obj->waitingForCommand) - 1);
obj->waitingForCommand[sizeof(obj->waitingForCommand) - 1] = '\0';
SUCCEED_RETURN(errctx);
}
bool akbasic_environment_is_waiting_for_any(akbasic_Environment *obj)
{
if ( obj == NULL ) {
return false;
}
if ( obj->waitingForCommand[0] != '\0' ) {
return true;
}
return akbasic_environment_is_waiting_for_any(obj->parent);
}
bool akbasic_environment_is_waiting_for(akbasic_Environment *obj, const char *command)
{
if ( obj == NULL || command == NULL ) {
return false;
}
if ( strcmp(obj->waitingForCommand, command) == 0 ) {
return true;
}
return akbasic_environment_is_waiting_for(obj->parent, command);
}
akerr_ErrorContext *akbasic_environment_stop_waiting(akbasic_Environment *obj, const char *command)
{
PREPARE_ERROR(errctx);
FAIL_ZERO_RETURN(errctx, (obj != NULL && command != NULL), AKERR_NULLPOINTER,
"NULL argument in stop_waiting");
/*
* The reference ignores `command` and clears unconditionally, which lets an
* inner block clear an outer block's wait (TODO.md section 12 item 3). The
* argument is honoured here only to the extent of walking to the environment
* that is actually waiting for it -- clearing the wrong one outright would
* change observable control flow, so the search stops at the first match and
* a miss is silently tolerated, exactly as today.
*/
while ( obj != NULL ) {
if ( strcmp(obj->waitingForCommand, command) == 0 ) {
obj->waitingForCommand[0] = '\0';
SUCCEED_RETURN(errctx);
}
obj = obj->parent;
}
SUCCEED_RETURN(errctx);
}
akerr_ErrorContext *akbasic_environment_get_function(akbasic_Environment *obj, const char *fname, void **dest)
{
PREPARE_ERROR(errctx);
char upper[AKBASIC_SYMTAB_MAX_KEY];
size_t i = 0;
size_t len = 0;
FAIL_ZERO_RETURN(errctx, (obj != NULL && fname != NULL && dest != NULL), AKERR_NULLPOINTER,
"NULL argument in get_function");
len = strlen(fname);
FAIL_ZERO_RETURN(errctx, (len < sizeof(upper)), AKERR_KEY, "Function '%s' is not defined", fname);
for ( i = 0; i < len; i++ ) {
char c = fname[i];
upper[i] = (char)((c >= 'a' && c <= 'z') ? (c - 'a' + 'A') : c);
}
upper[len] = '\0';
while ( obj != NULL ) {
akerr_ErrorContext *found = akbasic_symtab_get(&obj->functions, upper, dest, NULL);
if ( found == NULL ) {
SUCCEED_RETURN(errctx);
}
found->handled = true;
IGNORE(akerr_release_error(found));
obj = obj->parent;
}
FAIL_RETURN(errctx, AKERR_KEY, "Function '%s' is not defined", fname);
}
akerr_ErrorContext *akbasic_environment_get_label(akbasic_Environment *obj, const char *label, int64_t *dest)
{
PREPARE_ERROR(errctx);
FAIL_ZERO_RETURN(errctx, (obj != NULL && label != NULL && dest != NULL), AKERR_NULLPOINTER,
"NULL argument in get_label");
while ( obj != NULL ) {
akerr_ErrorContext *found = akbasic_symtab_get(&obj->labels, label, NULL, dest);
if ( found == NULL ) {
SUCCEED_RETURN(errctx);
}
found->handled = true;
IGNORE(akerr_release_error(found));
obj = obj->parent;
}
FAIL_RETURN(errctx, AKBASIC_ERR_UNDEFINED,
"Unable to find or create label %s in environment", label);
}
akerr_ErrorContext *akbasic_environment_set_label(akbasic_Environment *obj, const char *label, int64_t value)
{
PREPARE_ERROR(errctx);
FAIL_ZERO_RETURN(errctx, (obj != NULL && label != NULL), AKERR_NULLPOINTER,
"NULL argument in set_label");
/* Only the top-level environment creates labels. */
while ( obj != NULL && obj->runtime->environment != obj ) {
obj = obj->parent;
}
FAIL_ZERO_RETURN(errctx, (obj != NULL), AKBASIC_ERR_ENVIRONMENT,
"Unable to create label in orphaned environment");
PASS(errctx, akbasic_symtab_set(&obj->labels, label, NULL, value));
SUCCEED_RETURN(errctx);
}
akerr_ErrorContext *akbasic_environment_get(akbasic_Environment *obj, const char *varname, akbasic_Variable **dest)
{
PREPARE_ERROR(errctx);
akbasic_Environment *walk = NULL;
void *slot = NULL;
FAIL_ZERO_RETURN(errctx, (obj != NULL && varname != NULL && dest != NULL), AKERR_NULLPOINTER,
"NULL argument in environment get");
*dest = NULL;
for ( walk = obj; walk != NULL; walk = walk->parent ) {
akerr_ErrorContext *found = akbasic_symtab_get(&walk->variables, varname, &slot, NULL);
if ( found == NULL ) {
*dest = (akbasic_Variable *)slot;
SUCCEED_RETURN(errctx);
}
found->handled = true;
IGNORE(akerr_release_error(found));
}
/*
* Parents do not create variables for their children: only the currently
* active environment auto-creates. A miss anywhere else returns NULL without
* error, which the caller is expected to notice.
*/
if ( obj->runtime->environment != obj ) {
SUCCEED_RETURN(errctx);
}
Add akbasic_runtime_global: a host variable lands in the script's root scope A host creating a variable while a script was suspended got it in whatever scope was active -- usually a FOR or GOSUB body -- and it died when the body popped, silently. Reaching for the root by hand returned NULL without raising, because environment_get only auto-creates in the active environment. Both are still true of environment_get, which is correct for what the interpreter uses it for. The README and the example now point somewhere else. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Co-Authored-By: Andrew Kesterson <andrew@aklabs.net>
2026-07-31 11:53:05 -04:00
PASS(errctx, akbasic_environment_create(obj, varname, dest));
SUCCEED_RETURN(errctx);
}
akerr_ErrorContext *akbasic_environment_create(akbasic_Environment *obj, const char *varname, akbasic_Variable **dest)
{
PREPARE_ERROR(errctx);
akbasic_Variable *variable = NULL;
int64_t sizes[1] = { 1 };
void *slot = NULL;
akerr_ErrorContext *found = NULL;
FAIL_ZERO_RETURN(errctx, (obj != NULL && varname != NULL && dest != NULL), AKERR_NULLPOINTER,
"NULL argument in environment create");
/*
* This scope only. Unlike akbasic_environment_get() there is no walk up the
* parent chain: the caller has already said *which* scope it means, and
* finding an outer one would put the variable somewhere other than where it
* was asked for.
*/
*dest = NULL;
found = akbasic_symtab_get(&obj->variables, varname, &slot, NULL);
if ( found == NULL ) {
*dest = (akbasic_Variable *)slot;
SUCCEED_RETURN(errctx);
}
found->handled = true;
IGNORE(akerr_release_error(found));
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> Co-Authored-By: Andrew Kesterson <andrew@aklabs.net>
2026-07-30 23:53:56 -04:00
PASS(errctx, akbasic_runtime_new_variable(obj->runtime, &variable));
FAIL_ZERO_RETURN(errctx, (strlen(varname) < sizeof(variable->name)), AKBASIC_ERR_BOUNDS,
"Variable name '%s' is too long", varname);
strncpy(variable->name, varname, sizeof(variable->name) - 1);
variable->name[sizeof(variable->name) - 1] = '\0';
variable->valuetype = AKBASIC_TYPE_UNDEFINED;
variable->mutable_ = true;
PASS(errctx, akbasic_variable_init(variable, &obj->runtime->valuepool, sizes, 1));
PASS(errctx, akbasic_symtab_set(&obj->variables, varname, variable, 0));
*dest = variable;
SUCCEED_RETURN(errctx);
}
/*
* Evaluate an lvalue's subscript list, if it has one, into `subscripts`. A bare
* identifier yields the single subscript {0}, which is how a scalar is addressed
* -- every variable is really a one-element array.
*/
static akerr_ErrorContext *collect_subscripts(akbasic_Environment *obj, akbasic_ASTLeaf *lval, int64_t *subscripts, int *count)
{
PREPARE_ERROR(errctx);
akbasic_ASTLeaf *expr = NULL;
akbasic_Value *tval = NULL;
*count = 0;
Give argument lists their own link, not each argument's .right An identifier's subscript list, a unary's operand and a binary's right-hand side all lived in the same field the argument chain used, so ABS(-9), MOD(A#, B# + 12) and any array reference in a parameter list were counted as extra arguments and refused. Subscript lists move to .expr and arguments now chain through a dedicated .next. This is the third time the same collision was fixed; the first two moved it along rather than removing it. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Co-Authored-By: Andrew Kesterson <andrew@aklabs.net>
2026-07-31 11:58:15 -04:00
if ( lval->expr != NULL &&
lval->expr->leaftype == AKBASIC_LEAF_ARGUMENTLIST &&
lval->expr->operator_ == AKBASIC_TOK_ARRAY_SUBSCRIPT ) {
for ( expr = lval->expr->right; expr != NULL; expr = expr->next ) {
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> Co-Authored-By: Andrew Kesterson <andrew@aklabs.net>
2026-07-30 23:53:56 -04:00
FAIL_ZERO_RETURN(errctx, (*count < AKBASIC_MAX_ARRAY_DEPTH), AKBASIC_ERR_BOUNDS,
"More than %d array subscripts", AKBASIC_MAX_ARRAY_DEPTH);
PASS(errctx, akbasic_runtime_evaluate(obj->runtime, expr, &tval));
FAIL_NONZERO_RETURN(errctx, (tval->valuetype != AKBASIC_TYPE_INTEGER),
AKBASIC_ERR_TYPE,
"Array dimensions must evaluate to integer (B)");
subscripts[*count] = tval->intval;
*count += 1;
}
}
if ( *count == 0 ) {
subscripts[0] = 0;
*count = 1;
}
SUCCEED_RETURN(errctx);
}
akerr_ErrorContext *akbasic_environment_assign(akbasic_Environment *obj, akbasic_ASTLeaf *lval, akbasic_Value *rval, akbasic_Value **dest)
{
PREPARE_ERROR(errctx);
akbasic_Variable *variable = NULL;
int64_t subscripts[AKBASIC_MAX_ARRAY_DEPTH];
int subscriptcount = 0;
akbasic_Value *slot = NULL;
FAIL_ZERO_RETURN(errctx, (obj != NULL && lval != NULL && rval != NULL && dest != NULL),
AKERR_NULLPOINTER, "nil pointer");
PASS(errctx, akbasic_environment_get(obj, lval->identifier, &variable));
FAIL_ZERO_RETURN(errctx, (variable != NULL), AKBASIC_ERR_UNDEFINED,
"Identifier %s is undefined", lval->identifier);
PASS(errctx, collect_subscripts(obj, lval, subscripts, &subscriptcount));
/*
* Resolve the slot before the type switch. The reference notes that moving
* this below the switch corrupts the subscript list; here it is simply the
* clearer order, and the returned pointer is what an assignment expression
* evaluates to.
*/
PASS(errctx, akbasic_variable_get_subscript(variable, subscripts, subscriptcount, &slot));
switch ( lval->leaftype ) {
case AKBASIC_LEAF_IDENTIFIER_INT:
if ( rval->valuetype == AKBASIC_TYPE_INTEGER ) {
PASS(errctx, akbasic_variable_set_integer(variable, rval->intval, subscripts, subscriptcount));
} else if ( rval->valuetype == AKBASIC_TYPE_FLOAT ) {
PASS(errctx, akbasic_variable_set_integer(variable, (int64_t)rval->floatval, subscripts, subscriptcount));
} else {
FAIL_RETURN(errctx, AKBASIC_ERR_TYPE, "Incompatible types in variable assignment");
}
break;
case AKBASIC_LEAF_IDENTIFIER_FLOAT:
if ( rval->valuetype == AKBASIC_TYPE_INTEGER ) {
PASS(errctx, akbasic_variable_set_float(variable, (double)rval->intval, subscripts, subscriptcount));
} else if ( rval->valuetype == AKBASIC_TYPE_FLOAT ) {
PASS(errctx, akbasic_variable_set_float(variable, rval->floatval, subscripts, subscriptcount));
} else {
FAIL_RETURN(errctx, AKBASIC_ERR_TYPE, "Incompatible types in variable assignment");
}
break;
case AKBASIC_LEAF_IDENTIFIER_STRING:
FAIL_NONZERO_RETURN(errctx, (rval->valuetype != AKBASIC_TYPE_STRING), AKBASIC_ERR_TYPE,
"Incompatible types in variable assignment");
PASS(errctx, akbasic_variable_set_string(variable, rval->stringval, subscripts, subscriptcount));
break;
default:
FAIL_RETURN(errctx, AKBASIC_ERR_TYPE, "Invalid assignment");
}
variable->valuetype = rval->valuetype;
*dest = slot;
SUCCEED_RETURN(errctx);
}
Reference in New Issue Copy Permalink