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Finish the language: every remaining verb group, and the defects that blocked them

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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>
This commit is contained in:
Andrew Kesterson
2026-07-31 21:50:37 -04:00
parent 3aade4947a
commit 9845e77a5c
87 changed files with 11024 additions and 325 deletions
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118
src/runtime_graphics.c
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@@ -20,6 +20,7 @@
#include <akerror.h>
#include <akstdlib.h>
#include <akbasic/args.h>
#include <akbasic/error.h>
#include <akbasic/runtime.h>
@@ -56,54 +57,6 @@ static akerr_ErrorContext *require_graphics(akbasic_Runtime *obj, const char *ve
SUCCEED_RETURN(errctx);
}
/**
* @brief Collect a verb's arguments into an array, evaluating each one.
*
* The graphics verbs all take a short positional list with optional trailing
* members, so every handler wants the same thing: how many arguments arrived,
* and their numeric values. Strings are refused here rather than in each verb --
* SSHAPE and GSHAPE, which do take one, read their leaf directly instead.
*
* @param obj Runtime to evaluate against.
* @param expr The command leaf.
* @param verb Name to use in a diagnostic.
* @param values Where to put the evaluated arguments.
* @param max Capacity of `values`.
* @param count Output destination populated by the function.
*/
static akerr_ErrorContext *collect_numbers(akbasic_Runtime *obj, akbasic_ASTLeaf *expr, const char *verb, double *values, int max, int *count)
{
PREPARE_ERROR(errctx);
akbasic_ASTLeaf *arg = NULL;
akbasic_Value *value = NULL;
FAIL_ZERO_RETURN(errctx, (obj != NULL && expr != NULL && values != NULL && count != NULL),
AKERR_NULLPOINTER, "NULL argument in collect_numbers");
*count = 0;
arg = akbasic_leaf_first_argument(expr);
/*
* A loop, so CATCH and the _BREAK macros are banned in here -- they expand to
* a C break and would leave the loop with an error still pending. PASS and
* the _RETURN forms only.
*/
while ( arg != NULL ) {
FAIL_NONZERO_RETURN(errctx, (*count >= max), AKBASIC_ERR_SYNTAX,
"%s takes at most %d arguments", verb, max);
PASS(errctx, akbasic_runtime_evaluate(obj, arg, &value));
FAIL_NONZERO_RETURN(errctx, (value->valuetype == AKBASIC_TYPE_STRING),
AKBASIC_ERR_TYPE,
"%s expected a number in argument %d", verb, *count + 1);
if ( value->valuetype == AKBASIC_TYPE_FLOAT ) {
values[*count] = value->floatval;
} else {
values[*count] = (double)value->intval;
}
*count += 1;
arg = arg->next;
}
SUCCEED_RETURN(errctx);
}
/**
* @brief Map a user coordinate onto the 320x200 space the backend receives.
*
@@ -123,6 +76,47 @@ static void scale_point(akbasic_GraphicsState *gfx, double *x, double *y)
}
}
/**
* @brief Draw a line `WIDTH` pixels thick.
*
* BASIC 7.0's `WIDTH` sets the thickness of the lines the graphics verbs draw,
* and the backend record has no thickness argument -- neither does libakgl's
* akgl_draw_line, which is what it would have to reach. So a thick line is drawn
* as parallel passes, offset perpendicular to whichever axis the line runs along.
* That is what a C128 does in effect and it needs nothing new from the device.
*
* Approximate for a diagonal, where offsetting along one axis leaves the passes a
* fraction under a pixel apart. At WIDTH 2 -- the only other value the verb
* accepts -- that is not visible; a general thickness would want a real
* perpendicular offset and an API that takes one.
*/
static akerr_ErrorContext *draw_line(akbasic_Runtime *obj, double x1, double y1, double x2, double y2, akbasic_Color color)
{
PREPARE_ERROR(errctx);
double dx = (x2 > x1 ? x2 - x1 : x1 - x2);
double dy = (y2 > y1 ? y2 - y1 : y1 - y2);
bool steep = (dy > dx);
int pass = 0;
int width = (obj->gfx.linewidth > 0 ? obj->gfx.linewidth : 1);
/*
* A loop, so CATCH and the _BREAK macros are banned in here -- they expand
* to a C break and would leave the loop with an error still pending.
*/
for ( pass = 0; pass < width; pass++ ) {
double offset = (double)pass;
if ( steep ) {
PASS(errctx, obj->graphics->line(obj->graphics, x1 + offset, y1,
x2 + offset, y2, color));
} else {
PASS(errctx, obj->graphics->line(obj->graphics, x1, y1 + offset,
x2, y2 + offset, color));
}
}
SUCCEED_RETURN(errctx);
}
/* ------------------------------------------------------------- GRAPHIC --- */
akerr_ErrorContext *akbasic_cmd_graphic(akbasic_Runtime *obj, akbasic_ASTLeaf *expr, akbasic_Value *lval, akbasic_Value *rval, akbasic_Value **dest)
@@ -135,7 +129,7 @@ akerr_ErrorContext *akbasic_cmd_graphic(akbasic_Runtime *obj, akbasic_ASTLeaf *e
(void)lval; (void)rval;
PASS(errctx, require_graphics(obj, "GRAPHIC"));
PASS(errctx, collect_numbers(obj, expr, "GRAPHIC", args, 2, &count));
PASS(errctx, akbasic_args_numbers(obj, expr, "GRAPHIC", args, 2, &count));
FAIL_ZERO_RETURN(errctx, (count >= 1), AKBASIC_ERR_SYNTAX, "GRAPHIC expected a mode");
mode = (int)args[0];
@@ -186,7 +180,7 @@ akerr_ErrorContext *akbasic_cmd_color(akbasic_Runtime *obj, akbasic_ASTLeaf *exp
* colors up before the host has lent it a renderer.
*/
FAIL_ZERO_RETURN(errctx, (obj != NULL), AKERR_NULLPOINTER, "NULL runtime in COLOR");
PASS(errctx, collect_numbers(obj, expr, "COLOR", args, 2, &count));
PASS(errctx, akbasic_args_numbers(obj, expr, "COLOR", args, 2, &count));
FAIL_ZERO_RETURN(errctx, (count == 2), AKBASIC_ERR_SYNTAX,
"COLOR expected a source and a color");
@@ -212,7 +206,7 @@ akerr_ErrorContext *akbasic_cmd_locate(akbasic_Runtime *obj, akbasic_ASTLeaf *ex
(void)lval; (void)rval;
FAIL_ZERO_RETURN(errctx, (obj != NULL), AKERR_NULLPOINTER, "NULL runtime in LOCATE");
PASS(errctx, collect_numbers(obj, expr, "LOCATE", args, 2, &count));
PASS(errctx, akbasic_args_numbers(obj, expr, "LOCATE", args, 2, &count));
FAIL_ZERO_RETURN(errctx, (count == 2), AKBASIC_ERR_SYNTAX, "LOCATE expected X, Y");
/*
@@ -236,7 +230,7 @@ akerr_ErrorContext *akbasic_cmd_scale(akbasic_Runtime *obj, akbasic_ASTLeaf *exp
(void)lval; (void)rval;
FAIL_ZERO_RETURN(errctx, (obj != NULL), AKERR_NULLPOINTER, "NULL runtime in SCALE");
PASS(errctx, collect_numbers(obj, expr, "SCALE", args, 3, &count));
PASS(errctx, akbasic_args_numbers(obj, expr, "SCALE", args, 3, &count));
FAIL_ZERO_RETURN(errctx, (count >= 1), AKBASIC_ERR_SYNTAX, "SCALE expected 0 or 1");
/* Pure coordinate arithmetic -- nothing reaches the device. */
@@ -271,7 +265,7 @@ akerr_ErrorContext *akbasic_cmd_draw(akbasic_Runtime *obj, akbasic_ASTLeaf *expr
(void)lval; (void)rval;
PASS(errctx, require_graphics(obj, "DRAW"));
PASS(errctx, collect_numbers(obj, expr, "DRAW", args, 32, &count));
PASS(errctx, akbasic_args_numbers(obj, expr, "DRAW", args, 32, &count));
FAIL_ZERO_RETURN(errctx, (count >= 1), AKBASIC_ERR_SYNTAX,
"DRAW expected a color source");
FAIL_NONZERO_RETURN(errctx, (count > 1 && (count % 2) == 0), AKBASIC_ERR_SYNTAX,
@@ -308,7 +302,7 @@ akerr_ErrorContext *akbasic_cmd_draw(akbasic_Runtime *obj, akbasic_ASTLeaf *expr
y = args[i + 3];
scale_point(&obj->gfx, &px, &py);
scale_point(&obj->gfx, &x, &y);
PASS(errctx, obj->graphics->line(obj->graphics, px, py, x, y, color));
PASS(errctx, draw_line(obj, px, py, x, y, color));
}
obj->gfx.x = args[count - 2];
obj->gfx.y = args[count - 1];
@@ -340,7 +334,7 @@ akerr_ErrorContext *akbasic_cmd_box(akbasic_Runtime *obj, akbasic_ASTLeaf *expr,
(void)lval; (void)rval;
PASS(errctx, require_graphics(obj, "BOX"));
PASS(errctx, collect_numbers(obj, expr, "BOX", args, 6, &count));
PASS(errctx, akbasic_args_numbers(obj, expr, "BOX", args, 6, &count));
FAIL_ZERO_RETURN(errctx, (count >= 3), AKBASIC_ERR_SYNTAX,
"BOX expected a color source and at least one corner");
PASS(errctx, akbasic_graphics_source_color(&obj->gfx, (int)args[0], &color));
@@ -389,10 +383,8 @@ akerr_ErrorContext *akbasic_cmd_box(akbasic_Runtime *obj, akbasic_ASTLeaf *expr,
ys[corner] = cy + (ox * sin(radians)) + (oy * cos(radians));
}
for ( corner = 0; corner < 4; corner++ ) {
PASS(errctx, obj->graphics->line(obj->graphics,
xs[corner], ys[corner],
xs[(corner + 1) % 4], ys[(corner + 1) % 4],
color));
PASS(errctx, draw_line(obj, xs[corner], ys[corner],
xs[(corner + 1) % 4], ys[(corner + 1) % 4], color));
}
SUCCEED_TRUE(obj, dest);
SUCCEED_RETURN(errctx);
@@ -423,7 +415,7 @@ akerr_ErrorContext *akbasic_cmd_circle(akbasic_Runtime *obj, akbasic_ASTLeaf *ex
(void)lval; (void)rval;
PASS(errctx, require_graphics(obj, "CIRCLE"));
PASS(errctx, collect_numbers(obj, expr, "CIRCLE", args, 9, &count));
PASS(errctx, akbasic_args_numbers(obj, expr, "CIRCLE", args, 9, &count));
FAIL_ZERO_RETURN(errctx, (count >= 4), AKBASIC_ERR_SYNTAX,
"CIRCLE expected a color source, a center and a radius");
PASS(errctx, akbasic_graphics_source_color(&obj->gfx, (int)args[0], &color));
@@ -464,7 +456,7 @@ akerr_ErrorContext *akbasic_cmd_circle(akbasic_Runtime *obj, akbasic_ASTLeaf *ex
y = cy + (ox * sin(rot)) + (oy * cos(rot));
scale_point(&obj->gfx, &x, &y);
if ( !first ) {
PASS(errctx, obj->graphics->line(obj->graphics, px, py, x, y, color));
PASS(errctx, draw_line(obj, px, py, x, y, color));
}
first = false;
px = x;
@@ -493,7 +485,7 @@ akerr_ErrorContext *akbasic_cmd_paint(akbasic_Runtime *obj, akbasic_ASTLeaf *exp
(void)lval; (void)rval;
PASS(errctx, require_graphics(obj, "PAINT"));
PASS(errctx, collect_numbers(obj, expr, "PAINT", args, 4, &count));
PASS(errctx, akbasic_args_numbers(obj, expr, "PAINT", args, 4, &count));
FAIL_ZERO_RETURN(errctx, (count >= 3), AKBASIC_ERR_SYNTAX,
"PAINT expected a color source and a coordinate");
PASS(errctx, akbasic_graphics_source_color(&obj->gfx, (int)args[0], &color));
@@ -540,7 +532,7 @@ akerr_ErrorContext *akbasic_cmd_paint(akbasic_Runtime *obj, akbasic_ASTLeaf *exp
*
* SSHAPE and GSHAPE are the only two verbs in the group whose first argument is
* an identifier rather than a number, so they walk the leaf themselves instead
* of going through collect_numbers().
* of going through akbasic_args_numbers().
*/
static akerr_ErrorContext *shape_variable(akbasic_Runtime *obj, akbasic_ASTLeaf *expr, const char *verb, akbasic_Variable **dest, akbasic_ASTLeaf **rest)
{