* General Public License for more details.
*/
-#define DBG_EVAL 1
+#define DBG_EVAL 0
#include "ao_lisp.h"
#include <assert.h>
ao_lisp_poly_mark(stack->values, 0);
/* no need to mark values_tail */
ao_lisp_poly_mark(stack->frame, 0);
- ao_lisp_poly_mark(stack->macro_frame, 0);
stack = ao_lisp_poly_stack(stack->prev);
if (ao_lisp_mark_memory(stack, sizeof (struct ao_lisp_stack)))
break;
struct ao_lisp_stack *stack = addr;
while (stack) {
- void *prev;
+ struct ao_lisp_stack *prev;
int ret;
(void) ao_lisp_poly_move(&stack->sexprs, 0);
(void) ao_lisp_poly_move(&stack->values, 0);
(void) ao_lisp_poly_move(&stack->values_tail, 0);
(void) ao_lisp_poly_move(&stack->frame, 0);
- (void) ao_lisp_poly_move(&stack->macro_frame, 0);
prev = ao_lisp_poly_stack(stack->prev);
- ret = ao_lisp_move(&ao_lisp_stack_type, &prev);
+ ret = ao_lisp_move_memory((void **) &prev,
+ sizeof (struct ao_lisp_stack));
if (prev != ao_lisp_poly_stack(stack->prev))
stack->prev = ao_lisp_stack_poly(prev);
if (ret)
break;
- stack = ao_lisp_poly_stack(stack->prev);
+ stack = prev;
}
}
ao_lisp_stack_reset(struct ao_lisp_stack *stack)
{
stack->state = eval_sexpr;
- stack->macro = 0;
stack->sexprs = AO_LISP_NIL;
stack->values = AO_LISP_NIL;
stack->values_tail = AO_LISP_NIL;
}
-static void
-ao_lisp_frames_dump(void)
-{
- struct ao_lisp_stack *s;
- DBGI(".. current frame: "); DBG_POLY(ao_lisp_frame_poly(ao_lisp_frame_current)); DBG("\n");
- for (s = ao_lisp_stack; s; s = ao_lisp_poly_stack(s->prev)) {
- DBGI(".. stack frame: "); DBG_POLY(s->frame); DBG("\n");
- DBGI(".. macro frame: "); DBG_POLY(s->frame); DBG("\n");
- }
-}
static int
ao_lisp_stack_push(void)
{
- DBGI("stack push\n");
- DBG_IN();
struct ao_lisp_stack *stack = ao_lisp_alloc(sizeof (struct ao_lisp_stack));
if (!stack)
return 0;
stack->list = AO_LISP_NIL;
ao_lisp_stack = stack;
ao_lisp_stack_reset(stack);
- ao_lisp_frames_dump();
+ DBGI("stack push\n");
+ DBG_FRAMES();
+ DBG_IN();
return 1;
}
{
if (!ao_lisp_stack)
return;
- ao_lisp_frame_current = ao_lisp_poly_frame(ao_lisp_stack->frame);
ao_lisp_stack = ao_lisp_poly_stack(ao_lisp_stack->prev);
+ if (ao_lisp_stack)
+ ao_lisp_frame_current = ao_lisp_poly_frame(ao_lisp_stack->frame);
+ else
+ ao_lisp_frame_current = NULL;
DBG_OUT();
DBGI("stack pop\n");
- ao_lisp_frames_dump();
+ DBG_FRAMES();
}
static void
ao_lisp_eval_val(void)
{
DBGI("val: "); DBG_POLY(ao_lisp_v); DBG("\n");
- if (ao_lisp_stack->macro) {
- DBGI("..macro %d\n", ao_lisp_stack->macro);
- DBGI("..current frame "); DBG_POLY(ao_lisp_frame_poly(ao_lisp_frame_current)); DBG("\n");
- DBGI("..saved frame "); DBG_POLY(ao_lisp_stack->frame); DBG("\n");
- DBGI("..macro frame "); DBG_POLY(ao_lisp_stack->macro_frame); DBG("\n");
- DBGI("..sexprs "); DBG_POLY(ao_lisp_stack->sexprs); DBG("\n");
- DBGI("..values "); DBG_POLY(ao_lisp_stack->values); DBG("\n");
- /*
- * Re-use the current stack to evaluate
- * the value from the macro
- */
- ao_lisp_stack->state = eval_sexpr;
-// assert(ao_lisp_stack->frame == ao_lisp_stack->macro_frame);
- ao_lisp_frame_current = ao_lisp_poly_frame(ao_lisp_stack->macro_frame);
- ao_lisp_stack->frame = ao_lisp_stack->macro_frame;
- ao_lisp_stack->macro = 0;
- ao_lisp_stack->macro_frame = AO_LISP_NIL;
- ao_lisp_stack->sexprs = AO_LISP_NIL;
- ao_lisp_stack->values = AO_LISP_NIL;
- ao_lisp_stack->values_tail = AO_LISP_NIL;
- } else {
- /*
- * Value computed, pop the stack
- * to figure out what to do with the value
- */
- ao_lisp_stack_pop();
- }
+ /*
+ * Value computed, pop the stack
+ * to figure out what to do with the value
+ */
+ ao_lisp_stack_pop();
DBGI("..state %d\n", ao_lisp_stack ? ao_lisp_stack->state : -1);
return 1;
}
/*
* A formal has been computed.
*
- * If this is the first formal, then
- * check to see if we've got a lamda/lexpr or
- * macro/nlambda.
+ * If this is the first formal, then check to see if we've got a
+ * lamda/lexpr or macro/nlambda.
*
- * For lambda/lexpr, go compute another formal.
- * This will terminate when the sexpr state
- * sees nil.
+ * For lambda/lexpr, go compute another formal. This will terminate
+ * when the sexpr state sees nil.
*
- * For macro/nlambda, we're done, so move the
- * sexprs into the values and go execute it.
+ * For macro/nlambda, we're done, so move the sexprs into the values
+ * and go execute it.
+ *
+ * Macros have an additional step of saving a stack frame holding the
+ * macro value execution context, which then gets the result of the
+ * macro to run
*/
static int
ao_lisp_eval_formal(void)
{
- ao_poly formal;
+ ao_poly formal;
+ struct ao_lisp_stack *prev;
DBGI("formal: "); DBG_POLY(ao_lisp_v); DBG("\n");
DBGI(".. lambda or lexpr\n");
break;
case AO_LISP_FUNC_MACRO:
- ao_lisp_stack->macro = 1;
- DBGI(".. macro %d\n", ao_lisp_stack->macro);
- DBGI(".. frame "); DBG_POLY(ao_lisp_frame_poly(ao_lisp_frame_current)); DBG("\n");
- DBGI(".. saved frame "); DBG_POLY(ao_lisp_stack->frame); DBG("\n");
- ao_lisp_stack->macro_frame = ao_lisp_stack->frame;
+ /* Evaluate the result once more */
+ ao_lisp_stack->state = eval_sexpr;
+ if (!ao_lisp_stack_push())
+ return 0;
+
+ /* After the function returns, take that
+ * value and re-evaluate it
+ */
+ prev = ao_lisp_poly_stack(ao_lisp_stack->prev);
+ ao_lisp_stack->state = eval_sexpr;
+ ao_lisp_stack->sexprs = prev->sexprs;
+ prev->sexprs = AO_LISP_NIL;
+
+ DBGI(".. start macro\n");
+ DBGI(".. sexprs "); DBG_POLY(ao_lisp_stack->sexprs); DBG("\n");
+ DBGI(".. values "); DBG_POLY(ao_lisp_stack->values); DBG("\n");
+ DBG_FRAMES();
+
/* fall through ... */
case AO_LISP_FUNC_NLAMBDA:
DBGI(".. nlambda or macro\n");
+
+ /* use the raw sexprs as values */
ao_lisp_stack->values = ao_lisp_stack->sexprs;
ao_lisp_stack->values_tail = AO_LISP_NIL;
ao_lisp_stack->state = eval_exec;
+
+ /* ready to execute now */
return 1;
case -1:
return 0;
case AO_LISP_LAMBDA:
ao_lisp_stack->state = eval_sexpr;
DBGI(".. frame "); DBG_POLY(ao_lisp_frame_poly(ao_lisp_frame_current)); DBG("\n");
- ao_lisp_v = ao_lisp_lambda_eval(ao_lisp_poly_lambda(ao_lisp_v),
- ao_lisp_poly_cons(ao_lisp_stack->values));
+ ao_lisp_v = ao_lisp_lambda_eval();
DBGI(".. sexpr "); DBG_POLY(ao_lisp_v); DBG("\n");
DBGI(".. frame "); DBG_POLY(ao_lisp_frame_poly(ao_lisp_frame_current)); DBG("\n");
break;
return 1;
}
-static int
-ao_lisp_eval_lambda_done(void)
-{
- DBGI("lambda_done: "); DBG_POLY(ao_lisp_v); DBG("\n");
- DBG_STACK();
- return 1;
-}
-
/*
* Start evaluating the next cond clause
*
struct ao_lisp_cons *car = ao_lisp_poly_cons(ao_lisp_poly_cons(ao_lisp_stack->sexprs)->car);
struct ao_lisp_cons *c = ao_lisp_poly_cons(car->cdr);
- ao_lisp_stack->state = eval_val;
if (c) {
+ ao_lisp_stack->state = eval_sexpr;
ao_lisp_v = c->car;
- if (!ao_lisp_stack_push())
- return 0;
- }
+ } else
+ ao_lisp_stack->state = eval_val;
} else {
ao_lisp_stack->sexprs = ao_lisp_poly_cons(ao_lisp_stack->sexprs)->cdr;
DBGI("next cond: "); DBG_POLY(ao_lisp_stack->sexprs); DBG("\n");
return 1;
}
+/*
+ * Evaluate a list of sexprs, returning the value from the last one.
+ *
+ * ao_lisp_progn records the list in stack->sexprs, so we just need to
+ * walk that list. Set ao_lisp_v to the car of the list and jump to
+ * eval_sexpr. When that's done, it will land in eval_val. For all but
+ * the last, leave a stack frame with eval_progn set so that we come
+ * back here. For the last, don't add a stack frame so that we can
+ * just continue on.
+ */
+static int
+ao_lisp_eval_progn(void)
+{
+ DBGI("progn: "); DBG_POLY(ao_lisp_v); DBG(" sexprs "); DBG_POLY(ao_lisp_stack->sexprs); DBG("\n");
+ DBGI(".. frame "); DBG_POLY(ao_lisp_frame_poly(ao_lisp_frame_current)); DBG("\n");
+ DBGI(".. saved frame "); DBG_POLY(ao_lisp_stack->frame); DBG("\n");
+
+ if (!ao_lisp_stack->sexprs) {
+ ao_lisp_v = AO_LISP_NIL;
+ ao_lisp_stack->state = eval_val;
+ } else {
+ ao_lisp_v = ao_lisp_poly_cons(ao_lisp_stack->sexprs)->car;
+ ao_lisp_stack->sexprs = ao_lisp_poly_cons(ao_lisp_stack->sexprs)->cdr;
+ if (ao_lisp_stack->sexprs) {
+ ao_lisp_stack->state = eval_progn;
+ if (!ao_lisp_stack_push())
+ return 0;
+ }
+ ao_lisp_stack->state = eval_sexpr;
+ }
+ return 1;
+}
+
+/*
+ * Conditionally execute a list of sexprs while the first is true
+ */
+static int
+ao_lisp_eval_while(void)
+{
+ DBGI("while: "); DBG_POLY(ao_lisp_stack->sexprs); DBG("\n");
+ DBGI(".. frame "); DBG_POLY(ao_lisp_frame_poly(ao_lisp_frame_current)); DBG("\n");
+ DBGI(".. saved frame "); DBG_POLY(ao_lisp_stack->frame); DBG("\n");
+
+ if (!ao_lisp_stack->sexprs) {
+ ao_lisp_v = AO_LISP_NIL;
+ ao_lisp_stack->state = eval_val;
+ } else {
+ ao_lisp_v = ao_lisp_poly_cons(ao_lisp_stack->sexprs)->car;
+ ao_lisp_stack->state = eval_while_test;
+ if (!ao_lisp_stack_push())
+ return 0;
+ ao_lisp_stack->state = eval_sexpr;
+ }
+ return 1;
+}
+
+/*
+ * Check the while condition, terminate the loop if nil. Otherwise keep going
+ */
+static int
+ao_lisp_eval_while_test(void)
+{
+ DBGI("while_test: "); DBG_POLY(ao_lisp_v); DBG(" sexprs "); DBG_POLY(ao_lisp_stack->sexprs); DBG("\n");
+ DBGI(".. frame "); DBG_POLY(ao_lisp_frame_poly(ao_lisp_frame_current)); DBG("\n");
+ DBGI(".. saved frame "); DBG_POLY(ao_lisp_stack->frame); DBG("\n");
+
+ if (ao_lisp_v) {
+ ao_lisp_v = ao_lisp_poly_cons(ao_lisp_stack->sexprs)->cdr;
+ if (ao_lisp_v)
+ ao_lisp_v = ao_lisp_poly_cons(ao_lisp_v)->car;
+ ao_lisp_stack->state = eval_while;
+ if (!ao_lisp_stack_push())
+ return 0;
+ }
+ else
+ ao_lisp_stack->state = eval_val;
+ return 1;
+}
+
static int (*const evals[])(void) = {
[eval_sexpr] = ao_lisp_eval_sexpr,
[eval_val] = ao_lisp_eval_val,
[eval_exec] = ao_lisp_eval_exec,
[eval_cond] = ao_lisp_eval_cond,
[eval_cond_test] = ao_lisp_eval_cond_test,
+ [eval_progn] = ao_lisp_eval_progn,
+ [eval_while] = ao_lisp_eval_while,
+ [eval_while_test] = ao_lisp_eval_while_test,
};
ao_poly
return AO_LISP_NIL;
while (ao_lisp_stack) {
-// DBG_STACK();
if (!(*evals[ao_lisp_stack->state])() || ao_lisp_exception) {
ao_lisp_stack_clear();
return AO_LISP_NIL;
projects / fw / altos / blobdiff