Tachikoma
4e188b2794
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>
57 lines
2.2 KiB
C
57 lines
2.2 KiB
C
/**
|
|
* @file verbs.h
|
|
* @brief Declares the one dispatch table that replaces the reference's reflection.
|
|
*
|
|
* The Go runtime resolves a verb with reflect.MethodByName("Command" + NAME), a
|
|
* function with "Function" + NAME, and a special parse path with "ParseCommand" +
|
|
* NAME. C has no reflection and none is being added. All three collapse into the
|
|
* table in src/verbs.c: sorted by name, searched with bsearch, one row per verb.
|
|
*
|
|
* Adding a verb is adding one row and up to two functions. A NULL parse handler
|
|
* means "parse the rval as a plain expression", which is exactly what
|
|
* commandByReflection returning (nil, nil) means in the reference. A NULL exec
|
|
* handler means the token is consumed by another verb's parser and never
|
|
* evaluated on its own -- THEN, ELSE, TO and STEP are all like that.
|
|
*/
|
|
|
|
#ifndef _AKBASIC_VERBS_H_
|
|
#define _AKBASIC_VERBS_H_
|
|
|
|
#include <akerror.h>
|
|
|
|
#include <akbasic/grammar.h>
|
|
#include <akbasic/types.h>
|
|
|
|
struct akbasic_Parser;
|
|
struct akbasic_Runtime;
|
|
|
|
typedef akerr_ErrorContext AKERR_NOIGNORE *(*akbasic_ParseHandler)(struct akbasic_Parser *parser, akbasic_ASTLeaf **dest);
|
|
typedef akerr_ErrorContext AKERR_NOIGNORE *(*akbasic_ExecHandler)(struct akbasic_Runtime *obj, akbasic_ASTLeaf *expr, akbasic_Value *lval, akbasic_Value *rval, akbasic_Value **dest);
|
|
|
|
typedef struct
|
|
{
|
|
const char *name;
|
|
akbasic_TokenType tokentype;
|
|
int arity; /** Argument count for a function; -1 when not applicable */
|
|
akbasic_ParseHandler parse;
|
|
akbasic_ExecHandler exec;
|
|
} akbasic_Verb;
|
|
|
|
/**
|
|
* @brief Find a verb, function or reserved word by name, case-insensitively.
|
|
*
|
|
* Verbs and function names are case-insensitive in this dialect; variable names
|
|
* are not. That asymmetry lives here.
|
|
*
|
|
* @param name Name to look up; matched without regard to case.
|
|
* @param dest Output destination populated by the function; set to NULL on a miss.
|
|
* @return `NULL` on success, otherwise an error context owned by the caller.
|
|
* @throws AKERR_NULLPOINTER When `name` or `dest` is NULL.
|
|
*/
|
|
akerr_ErrorContext AKERR_NOIGNORE *akbasic_verb_lookup(const char *name, const akbasic_Verb **dest);
|
|
|
|
/** @brief The table itself, exposed so tests can assert it is sorted. */
|
|
const akbasic_Verb *akbasic_verb_table(int *count);
|
|
|
|
#endif // _AKBASIC_VERBS_H_
|