#include "ao_lisp.h"
-/*
- * Non-recursive eval
- *
- * Plan: walk actuals, construct formals
- *
- * stack > save > actuals > actual_1
- * v v
- * formals . > actual_2
- */
-
-static struct ao_lisp_cons *stack;
-static struct ao_lisp_cons *actuals;
-static struct ao_lisp_cons *formals;
-static struct ao_lisp_cons *formals_tail;
-static uint8_t been_here;
-
#if 0
#define DBG(...) printf(__VA_ARGS__)
-#define DBG_CONS(a) ao_lisp_cons_print(a)
+#define DBG_CONS(a) ao_lisp_cons_print(ao_lisp_cons_poly(a))
#define DBG_POLY(a) ao_lisp_poly_print(a)
+#define OFFSET(a) ((a) ? (int) ((uint8_t *) a - ao_lisp_pool) : -1)
#else
#define DBG(...)
#define DBG_CONS(a)
#define DBG_POLY(a)
#endif
-ao_lisp_poly
-ao_lisp_eval(ao_lisp_poly v)
+struct ao_lisp_stack {
+ ao_poly next;
+ ao_poly actuals;
+ ao_poly formals;
+ ao_poly frame;
+ ao_poly cond;
+};
+
+static struct ao_lisp_stack *
+ao_lisp_poly_stack(ao_poly p)
+{
+ return ao_lisp_ref(p);
+}
+
+static ao_poly
+ao_lisp_stack_poly(struct ao_lisp_stack *stack)
+{
+ return ao_lisp_poly(stack, AO_LISP_OTHER);
+}
+
+static int
+stack_size(void *addr)
+{
+ (void) addr;
+ return sizeof (struct ao_lisp_stack);
+}
+
+static void
+stack_mark(void *addr)
+{
+ struct ao_lisp_stack *stack = addr;
+ for (;;) {
+ ao_lisp_poly_mark(stack->actuals);
+ ao_lisp_poly_mark(stack->formals);
+ ao_lisp_poly_mark(stack->frame);
+ ao_lisp_poly_mark(stack->cond);
+ stack = ao_lisp_poly_stack(stack->next);
+ if (ao_lisp_mark_memory(stack, sizeof (struct ao_lisp_stack)))
+ break;
+ }
+}
+
+static void
+stack_move(void *addr)
+{
+ struct ao_lisp_stack *stack = addr;
+
+ for (;;) {
+ struct ao_lisp_stack *next;
+ stack->actuals = ao_lisp_poly_move(stack->actuals);
+ stack->formals = ao_lisp_poly_move(stack->formals);
+ stack->frame = ao_lisp_poly_move(stack->frame);
+ stack->cond = ao_lisp_poly_move(stack->cond);
+ next = ao_lisp_ref(stack->next);
+ next = ao_lisp_move_memory(next, sizeof (struct ao_lisp_stack));
+ stack->next = ao_lisp_stack_poly(next);
+ stack = next;
+ }
+}
+
+static const struct ao_lisp_type ao_lisp_stack_type = {
+ .size = stack_size,
+ .mark = stack_mark,
+ .move = stack_move
+};
+
+
+static struct ao_lisp_stack *stack;
+static struct ao_lisp_cons *actuals;
+static struct ao_lisp_cons *formals;
+static struct ao_lisp_cons *formals_tail;
+static struct ao_lisp_cons *cond;
+struct ao_lisp_frame *next_frame;
+static uint8_t been_here;
+
+ao_poly
+ao_lisp_set_cond(struct ao_lisp_cons *c)
+{
+ cond = c;
+ return AO_LISP_NIL;
+}
+
+static int
+ao_lisp_stack_push(void)
+{
+ struct ao_lisp_stack *n = ao_lisp_alloc(sizeof (struct ao_lisp_stack));
+ if (!n)
+ return 0;
+ n->next = ao_lisp_stack_poly(stack);
+ n->actuals = ao_lisp_cons_poly(actuals);
+ n->formals = ao_lisp_cons_poly(formals);
+ n->cond = ao_lisp_cons_poly(cond);
+ n->frame = ao_lisp_frame_poly(ao_lisp_frame_current);
+ DBG("push frame %d\n", OFFSET(ao_lisp_frame_current));
+ stack = n;
+ return 1;
+}
+
+static void
+ao_lisp_stack_pop(void)
+{
+ actuals = ao_lisp_poly_cons(stack->actuals);
+ formals = ao_lisp_poly_cons(stack->formals);
+ cond = ao_lisp_poly_cons(stack->cond);
+ ao_lisp_frame_current = ao_lisp_poly_frame(stack->frame);
+ DBG("pop frame %d\n", OFFSET(ao_lisp_frame_current));
+ formals_tail = 0;
+
+ /* Recompute the tail of the formals list */
+ if (formals) {
+ struct ao_lisp_cons *formal;
+ for (formal = formals; formal->cdr != AO_LISP_NIL; formal = ao_lisp_poly_cons(formal->cdr));
+ formals_tail = formal;
+ }
+ stack = ao_lisp_poly_stack(stack->next);
+}
+
+static void
+ao_lisp_stack_clear(void)
+{
+ stack = 0;
+ actuals = formals = formals_tail = 0;
+ cond = 0;
+ ao_lisp_frame_current = 0;
+}
+
+
+static ao_poly
+func_type(ao_poly func)
+{
+ struct ao_lisp_cons *cons;
+ struct ao_lisp_cons *args;
+ int f;
+
+ DBG("func type "); DBG_POLY(func); DBG("\n");
+ if (func == AO_LISP_NIL)
+ return ao_lisp_error(AO_LISP_INVALID, "func is nil");
+ if (ao_lisp_poly_type(func) != AO_LISP_CONS)
+ return ao_lisp_error(AO_LISP_INVALID, "func is not list");
+ cons = ao_lisp_poly_cons(func);
+ if (!ao_lisp_check_argc(_ao_lisp_atom_lambda, cons, 3, 3))
+ return AO_LISP_NIL;
+ if (!ao_lisp_check_argt(_ao_lisp_atom_lambda, cons, 0, AO_LISP_ATOM, 0))
+ return AO_LISP_NIL;
+ if (!ao_lisp_check_argt(_ao_lisp_atom_lambda, cons, 1, AO_LISP_CONS, 1))
+ return AO_LISP_NIL;
+ args = ao_lisp_poly_cons(ao_lisp_arg(cons, 1));
+ f = 0;
+ while (args) {
+ if (ao_lisp_poly_type(args->car) != AO_LISP_ATOM) {
+ return ao_lisp_error(ao_lisp_arg(cons, 0), "formal %d is not an atom", f);
+ }
+ args = ao_lisp_poly_cons(args->cdr);
+ f++;
+ }
+ return ao_lisp_arg(cons, 0);
+}
+
+static int
+ao_lisp_cons_length(struct ao_lisp_cons *cons)
+{
+ int len = 0;
+ while (cons) {
+ len++;
+ cons = ao_lisp_poly_cons(cons->cdr);
+ }
+ return len;
+}
+
+static ao_poly
+ao_lisp_lambda(struct ao_lisp_cons *cons)
+{
+ ao_poly type;
+ struct ao_lisp_cons *lambda;
+ struct ao_lisp_cons *args;
+ int args_wanted;
+ int args_provided;
+
+ lambda = ao_lisp_poly_cons(ao_lisp_arg(cons, 0));
+ DBG("lambda "); DBG_CONS(lambda); DBG("\n");
+ type = ao_lisp_arg(lambda, 0);
+ args = ao_lisp_poly_cons(ao_lisp_arg(lambda, 1));
+
+ args_wanted = ao_lisp_cons_length(args);
+
+ /* Create a frame to hold the variables
+ */
+ if (type == _ao_lisp_atom_lambda)
+ args_provided = ao_lisp_cons_length(cons) - 1;
+ else
+ args_provided = 1;
+ if (args_wanted != args_provided)
+ return ao_lisp_error(AO_LISP_INVALID, "need %d args, not %d", args_wanted, args_provided);
+ next_frame = ao_lisp_frame_new(args_wanted, 0);
+ DBG("new frame %d\n", OFFSET(next_frame));
+ switch (type) {
+ case _ao_lisp_atom_lambda: {
+ int f;
+ struct ao_lisp_cons *vals = ao_lisp_poly_cons(cons->cdr);
+
+ for (f = 0; f < args_wanted; f++) {
+ next_frame->vals[f].atom = args->car;
+ next_frame->vals[f].val = vals->car;
+ args = ao_lisp_poly_cons(args->cdr);
+ vals = ao_lisp_poly_cons(vals->cdr);
+ }
+ break;
+ }
+ case _ao_lisp_atom_lexpr:
+ case _ao_lisp_atom_nlambda:
+ next_frame->vals[0].atom = args->car;
+ next_frame->vals[0].val = cons->cdr;
+ break;
+ case _ao_lisp_atom_macro:
+ next_frame->vals[0].atom = args->car;
+ next_frame->vals[0].val = ao_lisp_cons_poly(cons);
+ break;
+ }
+ return ao_lisp_arg(lambda, 2);
+}
+
+ao_poly
+ao_lisp_eval(ao_poly v)
{
struct ao_lisp_cons *formal;
int cons = 0;
if (!been_here) {
been_here = 1;
- ao_lisp_root_add(&ao_lisp_cons_type, &stack);
+ ao_lisp_root_add(&ao_lisp_stack_type, &stack);
ao_lisp_root_add(&ao_lisp_cons_type, &actuals);
ao_lisp_root_add(&ao_lisp_cons_type, &formals);
ao_lisp_root_add(&ao_lisp_cons_type, &formals_tail);
actuals = 0;
formals = 0;
formals_tail = 0;
+ cond = 0;
for (;;) {
+ restart:
+ if (cond) {
+ if (cond->car == AO_LISP_NIL) {
+ cond = AO_LISP_NIL;
+ v = AO_LISP_NIL;
+ } else {
+ if (ao_lisp_poly_type(cond->car) != AO_LISP_CONS) {
+ ao_lisp_error(AO_LISP_INVALID, "malformed cond");
+ goto bail;
+ }
+ v = ao_lisp_poly_cons(cond->car)->car;
+ }
+ }
+
/* Build stack frames for each list */
while (ao_lisp_poly_type(v) == AO_LISP_CONS) {
if (v == AO_LISP_NIL)
break;
- /* Push existing frame on the stack */
- if (cons++) {
- struct ao_lisp_cons *frame;
+ /* Push existing bits on the stack */
+ if (cons++)
+ if (!ao_lisp_stack_push())
+ goto bail;
- frame = ao_lisp_cons(ao_lisp_cons_poly(actuals), formals);
- stack = ao_lisp_cons(ao_lisp_cons_poly(frame), stack);
- }
actuals = ao_lisp_poly_cons(v);
formals = NULL;
formals_tail = NULL;
+ cond = NULL;
+
v = actuals->car;
- DBG("start: stack"); DBG_CONS(stack); DBG("\n");
- DBG("start: actuals"); DBG_CONS(actuals); DBG("\n");
- DBG("start: formals"); DBG_CONS(formals); DBG("\n");
+// DBG("start: stack"); DBG_CONS(stack); DBG("\n");
+// DBG("start: actuals"); DBG_CONS(actuals); DBG("\n");
+// DBG("start: formals"); DBG_CONS(formals); DBG("\n");
}
/* Evaluate primitive types */
+ DBG ("actual: "); DBG_POLY(v); DBG("\n");
+
switch (ao_lisp_poly_type(v)) {
case AO_LISP_INT:
case AO_LISP_STRING:
break;
case AO_LISP_ATOM:
- v = ao_lisp_poly_atom(v)->val;
+ v = ao_lisp_atom_get(v);
break;
}
- for (;;) {
+ while (cons) {
DBG("add formal: "); DBG_POLY(v); DBG("\n");
- formal = ao_lisp_cons(v, NULL);
+ /* We've processed the first element of the list, go check
+ * what kind of function we've got
+ */
+ if (formals == NULL) {
+ if (ao_lisp_poly_type(v) == AO_LISP_BUILTIN) {
+ struct ao_lisp_builtin *b = ao_lisp_poly_builtin(v);
+ switch (b->args) {
+ case AO_LISP_NLAMBDA:
+ formals = actuals;
+ goto eval;
+
+ case AO_LISP_MACRO:
+ v = ao_lisp_func(b)(ao_lisp_poly_cons(actuals->cdr));
+ DBG("macro "); DBG_POLY(ao_lisp_cons_poly(actuals));
+ DBG(" -> "); DBG_POLY(v);
+ DBG("\n");
+ if (ao_lisp_poly_type(v) != AO_LISP_CONS) {
+ ao_lisp_error(AO_LISP_INVALID, "macro didn't return list");
+ goto bail;
+ }
+ /* Reset frame to the new list */
+ actuals = ao_lisp_poly_cons(v);
+ v = actuals->car;
+ goto restart;
+ }
+ } else {
+ switch (func_type(v)) {
+ case _ao_lisp_atom_lambda:
+ case _ao_lisp_atom_lexpr:
+ break;
+ case _ao_lisp_atom_nlambda:
+ formals = actuals;
+ goto eval;
+ case _ao_lisp_atom_macro:
+ break;
+ default:
+ ao_lisp_error(AO_LISP_INVALID, "operator is not a function");
+ goto bail;
+ }
+ }
+ }
+
+ formal = ao_lisp_cons_cons(v, NULL);
if (formals_tail)
- formals_tail->cdr = formal;
+ formals_tail->cdr = ao_lisp_cons_poly(formal);
else
formals = formal;
formals_tail = formal;
- actuals = actuals->cdr;
+ actuals = ao_lisp_poly_cons(actuals->cdr);
DBG("formals: ");
DBG_CONS(formals);
/* Process all of the arguments */
if (actuals) {
v = actuals->car;
- DBG ("actual: "); DBG_POLY(v); DBG("\n");
break;
}
v = formals->car;
+ eval:
+
/* Evaluate the resulting list */
if (ao_lisp_poly_type(v) == AO_LISP_BUILTIN) {
struct ao_lisp_builtin *b = ao_lisp_poly_builtin(v);
- v = b->func(formals->cdr);
+ v = ao_lisp_func(b) (ao_lisp_poly_cons(formals->cdr));
DBG ("eval: ");
DBG_CONS(formals);
DBG(" -> ");
DBG_POLY(v);
DBG ("\n");
+ if (ao_lisp_exception)
+ goto bail;
+
+ if (cond)
+ goto restart;
} else {
- DBG ("invalid eval\n");
+ v = ao_lisp_lambda(formals);
+ if (ao_lisp_exception)
+ goto bail;
}
- if (--cons) {
- struct ao_lisp_cons *frame;
-
- /* Pop the previous frame off the stack */
- frame = ao_lisp_poly_cons(stack->car);
- actuals = ao_lisp_poly_cons(frame->car);
- formals = frame->cdr;
-
- /* Recompute the tail of the formals list */
- for (formal = formals; formal->cdr != NULL; formal = formal->cdr);
- formals_tail = formal;
-
- stack = stack->cdr;
- DBG("stack pop: stack"); DBG_CONS(stack); DBG("\n");
- DBG("stack pop: actuals"); DBG_CONS(actuals); DBG("\n");
- DBG("stack pop: formals"); DBG_CONS(formals); DBG("\n");
+ --cons;
+ if (cons) {
+ ao_lisp_stack_pop();
+// DBG("stack pop: stack"); DBG_CONS(stack); DBG("\n");
+// DBG("stack pop: actuals"); DBG_CONS(actuals); DBG("\n");
+// DBG("stack pop: formals"); DBG_CONS(formals); DBG("\n");
} else {
- DBG("done func\n");
- break;
+ actuals = 0;
+ formals = 0;
+ formals_tail = 0;
+ ao_lisp_frame_current = 0;
+ }
+ if (next_frame) {
+ ao_lisp_frame_current = next_frame;
+ DBG("next frame %d\n", OFFSET(next_frame));
+ next_frame = 0;
+ goto restart;
+ }
+ if (cond) {
+ if (v) {
+ v = ao_lisp_poly_cons(cond->car)->cdr;
+ if (v != AO_LISP_NIL) {
+ v = ao_lisp_poly_cons(v)->car;
+ goto restart;
+ }
+ } else {
+ cond = ao_lisp_poly_cons(cond->cdr);
+ goto restart;
+ }
}
}
if (!cons)
break;
}
+ DBG("leaving frame at %d\n", OFFSET(ao_lisp_frame_current));
return v;
+bail:
+ ao_lisp_stack_clear();
+ return AO_LISP_NIL;
}
projects / fw / altos / blobdiff