#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_CODE 1
+static int stack_depth;
+#define DBG_INDENT() do { int _s; for(_s = 0; _s < stack_depth; _s++) printf(" "); } while(0)
+#define DBG_IN() (++stack_depth)
+#define DBG_OUT() (--stack_depth)
+#define DBG(...) printf(__VA_ARGS__)
+#define DBGI(...) do { DBG_INDENT(); DBG("%4d: ", __LINE__); DBG(__VA_ARGS__); } while (0)
+#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_INDENT()
+#define DBG_IN()
+#define DBG_OUT()
#define DBG(...)
+#define DBGI(...)
#define DBG_CONS(a)
#define DBG_POLY(a)
#endif
+enum eval_state {
+ eval_sexpr,
+ eval_val,
+ eval_formal,
+ eval_exec,
+ eval_exec_direct,
+ eval_cond,
+ eval_cond_test
+};
+
+struct ao_lisp_stack {
+ ao_poly prev;
+ uint8_t state;
+ uint8_t macro;
+ ao_poly actuals;
+ ao_poly formals;
+ ao_poly formals_tail;
+ ao_poly frame;
+};
+
+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);
+ /* no need to mark formals_tail */
+ ao_lisp_poly_mark(stack->frame);
+ stack = ao_lisp_poly_stack(stack->prev);
+ if (ao_lisp_mark_memory(stack, sizeof (struct ao_lisp_stack)))
+ break;
+ }
+}
+
+static const struct ao_lisp_type ao_lisp_stack_type;
+
+#if DBG_CODE
+static void
+stack_validate_tail(struct ao_lisp_stack *stack)
+{
+ struct ao_lisp_cons *head = ao_lisp_poly_cons(stack->formals);
+ struct ao_lisp_cons *tail = ao_lisp_poly_cons(stack->formals_tail);
+ struct ao_lisp_cons *cons;
+ for (cons = head; cons && cons->cdr && cons != tail; cons = ao_lisp_poly_cons(cons->cdr))
+ ;
+ if (cons != tail || (tail && tail->cdr)) {
+ if (!tail) {
+ printf("tail null\n");
+ } else {
+ printf("tail validate fail head %d actual %d recorded %d\n",
+ OFFSET(head), OFFSET(cons), OFFSET(tail));
+ abort();
+ }
+ }
+}
+#else
+#define stack_validate_tail(s)
+#endif
+
+static void
+stack_move(void *addr)
+{
+ struct ao_lisp_stack *stack = addr;
+
+ while (stack) {
+ void *prev;
+ int ret;
+ (void) ao_lisp_poly_move(&stack->actuals);
+ (void) ao_lisp_poly_move(&stack->formals);
+ (void) ao_lisp_poly_move(&stack->formals_tail);
+ (void) ao_lisp_poly_move(&stack->frame);
+ prev = ao_lisp_poly_stack(stack->prev);
+ ret = ao_lisp_move(&ao_lisp_stack_type, &prev);
+ if (prev != ao_lisp_poly_stack(stack->prev))
+ stack->prev = ao_lisp_stack_poly(prev);
+ stack_validate_tail(stack);
+ if (ret)
+ break;
+ stack = ao_lisp_poly_stack(stack->prev);
+ }
+}
+
+static const struct ao_lisp_type ao_lisp_stack_type = {
+ .size = stack_size,
+ .mark = stack_mark,
+ .move = stack_move
+};
+
+static struct ao_lisp_stack *ao_lisp_stack;
+static ao_poly ao_lisp_v;
+static uint8_t been_here;
+
+#if DBG_CODE
+static void
+stack_validate_tails(void)
+{
+ struct ao_lisp_stack *stack;
+
+ for (stack = ao_lisp_stack; stack; stack = ao_lisp_poly_stack(stack->prev))
+ stack_validate_tail(stack);
+}
+#else
+#define stack_validate_tails(s)
+#endif
+
ao_poly
-ao_lisp_eval(ao_poly v)
+ao_lisp_set_cond(struct ao_lisp_cons *c)
{
- struct ao_lisp_cons *formal;
- int cons = 0;
+ ao_lisp_stack->state = eval_cond;
+ ao_lisp_stack->actuals = ao_lisp_cons_poly(c);
+ return AO_LISP_NIL;
+}
- if (!been_here) {
- been_here = 1;
- ao_lisp_root_add(&ao_lisp_cons_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);
+void
+ao_lisp_stack_reset(struct ao_lisp_stack *stack)
+{
+ stack->state = eval_sexpr;
+ stack->macro = 0;
+ stack->actuals = AO_LISP_NIL;
+ stack->formals = AO_LISP_NIL;
+ stack->formals_tail = AO_LISP_NIL;
+ stack->frame = ao_lisp_frame_poly(ao_lisp_frame_current);
+ stack_validate_tails();
+}
+
+int
+ao_lisp_stack_push(void)
+{
+ stack_validate_tails();
+ if (ao_lisp_stack) {
+ DBGI("formals "); DBG_POLY(ao_lisp_stack->formals); DBG("\n");
+ DBGI("actuals "); DBG_POLY(ao_lisp_stack->actuals); DBG("\n");
}
- stack = 0;
- actuals = 0;
- formals = 0;
- formals_tail = 0;
- for (;;) {
+ DBGI("stack push\n");
+ DBG_IN();
+ struct ao_lisp_stack *stack = ao_lisp_alloc(sizeof (struct ao_lisp_stack));
+ if (!stack)
+ return 0;
+ stack->prev = ao_lisp_stack_poly(ao_lisp_stack);
+ ao_lisp_stack = stack;
+ ao_lisp_stack_reset(stack);
+ stack_validate_tails();
+ return 1;
+}
- restart:
- /* Build stack frames for each list */
- while (ao_lisp_poly_type(v) == AO_LISP_CONS) {
- if (v == AO_LISP_NIL)
- break;
+void
+ao_lisp_stack_pop(void)
+{
+ if (!ao_lisp_stack)
+ return;
+ stack_validate_tails();
+ DBG_OUT();
+ DBGI("stack pop\n");
+ 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;
+ if (ao_lisp_stack) {
+ DBGI("formals "); DBG_POLY(ao_lisp_stack->formals); DBG("\n");
+ DBGI("actuals "); DBG_POLY(ao_lisp_stack->actuals); DBG("\n");
+ }
+}
+
+static void
+ao_lisp_stack_clear(void)
+{
+ stack_validate_tails();
+ ao_lisp_stack = NULL;
+ ao_lisp_frame_current = NULL;
+}
- /* Push existing frame on the stack */
- if (cons++) {
- struct ao_lisp_cons *frame;
+static ao_poly
+func_type(ao_poly func)
+{
+ struct ao_lisp_cons *cons;
+ struct ao_lisp_cons *args;
+ int f;
- frame = ao_lisp_cons_cons(ao_lisp_cons_poly(actuals), formals);
- stack = ao_lisp_cons_cons(ao_lisp_cons_poly(frame), stack);
+ DBGI("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_BUILTIN) {
+ struct ao_lisp_builtin *b = ao_lisp_poly_builtin(func);
+ return b->args;
+ } else if (ao_lisp_poly_type(func) == AO_LISP_CONS) {
+ 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);
}
- actuals = ao_lisp_poly_cons(v);
- formals = NULL;
- formals_tail = 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");
+ args = ao_lisp_poly_cons(args->cdr);
+ f++;
}
+ return ao_lisp_arg(cons, 0);
+ } else {
+ ao_lisp_error(AO_LISP_INVALID, "not a func");
+ abort();
+ return AO_LISP_NIL;
+ }
+}
- /* Evaluate primitive types */
+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;
+}
- DBG ("actual: "); DBG_POLY(v); DBG("\n");
+static ao_poly
+ao_lisp_lambda(struct ao_lisp_cons *cons)
+{
+ ao_poly type;
+ struct ao_lisp_cons *lambda;
+ struct ao_lisp_cons *args;
+ struct ao_lisp_frame *next_frame;
+ int args_wanted;
+ int args_provided;
- 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;
- break;
+ lambda = ao_lisp_poly_cons(ao_lisp_arg(cons, 0));
+ DBGI("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);
+// DBGI("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;
+ }
+ next_frame->next = ao_lisp_frame_poly(ao_lisp_frame_current);
+ ao_lisp_frame_current = next_frame;
+ ao_lisp_stack->frame = ao_lisp_frame_poly(next_frame);
+ return ao_lisp_arg(lambda, 2);
+}
+
+ao_poly
+ao_lisp_eval(ao_poly _v)
+{
+ ao_poly formal;
+
+ ao_lisp_v = _v;
+ if (!been_here) {
+ been_here = 1;
+ ao_lisp_root_add(&ao_lisp_stack_type, &ao_lisp_stack);
+ ao_lisp_root_poly_add(&ao_lisp_v);
+ }
+
+ if (!ao_lisp_stack_push())
+ goto bail;
- if (!cons)
+ for (;;) {
+ if (ao_lisp_exception)
+ goto bail;
+ switch (ao_lisp_stack->state) {
+ case eval_sexpr:
+ DBGI("sexpr: "); DBG_POLY(ao_lisp_v); DBG("\n");
+ switch (ao_lisp_poly_type(ao_lisp_v)) {
+ case AO_LISP_CONS:
+ if (ao_lisp_v == AO_LISP_NIL) {
+ ao_lisp_stack->state = eval_exec;
+ break;
+ }
+ ao_lisp_stack->actuals = ao_lisp_v;
+ DBGI("actuals now "); DBG_POLY(ao_lisp_v); DBG("\n");
+ ao_lisp_stack->state = eval_formal;
+ if (!ao_lisp_stack_push())
+ goto bail;
+ ao_lisp_v = ao_lisp_poly_cons(ao_lisp_v)->car;
+ stack_validate_tails();
+ break;
+ case AO_LISP_ATOM:
+ ao_lisp_v = ao_lisp_atom_get(ao_lisp_v);
+ /* fall through */
+ case AO_LISP_INT:
+ case AO_LISP_STRING:
+ case AO_LISP_BUILTIN:
+ ao_lisp_stack->state = eval_val;
+ break;
+ }
+ break;
+ case eval_val:
+ DBGI("val: "); DBG_POLY(ao_lisp_v); DBG("\n");
+ ao_lisp_stack_pop();
+ if (!ao_lisp_stack)
+ return ao_lisp_v;
+ DBGI("..state %d\n", ao_lisp_stack->state);
break;
- for (;;) {
- DBG("add formal: "); DBG_POLY(v); DBG("\n");
-
- 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:
- v = ao_lisp_func(b)(ao_lisp_poly_cons(actuals->cdr));
- goto done_eval;
-
- case AO_LISP_MACRO:
- v = ao_lisp_func(b)(ao_lisp_poly_cons(actuals->cdr));
- if (ao_lisp_poly_type(v) != AO_LISP_CONS) {
- ao_lisp_exception |= AO_LISP_INVALID;
- return AO_LISP_NIL;
- }
-
- /* Reset frame to the new list */
- actuals = ao_lisp_poly_cons(v);
- v = actuals->car;
- goto restart;
- }
+ case eval_formal:
+ /* Check what kind of function we've got */
+ if (!ao_lisp_stack->formals) {
+ switch (func_type(ao_lisp_v)) {
+ case AO_LISP_LAMBDA:
+ case _ao_lisp_atom_lambda:
+ case AO_LISP_LEXPR:
+ case _ao_lisp_atom_lexpr:
+ DBGI(".. lambda or lexpr\n");
+ break;
+ case AO_LISP_MACRO:
+ case _ao_lisp_atom_macro:
+ ao_lisp_stack->macro = 1;
+ case AO_LISP_NLAMBDA:
+ case _ao_lisp_atom_nlambda:
+ DBGI(".. nlambda or macro\n");
+ ao_lisp_stack->formals = ao_lisp_stack->actuals;
+ ao_lisp_stack->formals_tail = AO_LISP_NIL;
+ ao_lisp_stack->state = eval_exec_direct;
+ stack_validate_tails();
+ break;
}
+ if (ao_lisp_stack->state == eval_exec_direct)
+ break;
}
- formal = ao_lisp_cons_cons(v, NULL);
- if (formals_tail)
- formals_tail->cdr = ao_lisp_cons_poly(formal);
+ DBGI("add formal "); DBG_POLY(ao_lisp_v); DBG("\n");
+ stack_validate_tails();
+ formal = ao_lisp_cons_poly(ao_lisp_cons_cons(ao_lisp_v, NULL));
+ stack_validate_tails();
+ if (!formal)
+ goto bail;
+
+ if (ao_lisp_stack->formals_tail)
+ ao_lisp_poly_cons(ao_lisp_stack->formals_tail)->cdr = formal;
else
- formals = formal;
- formals_tail = formal;
- actuals = ao_lisp_poly_cons(actuals->cdr);
-
- DBG("formals: ");
- DBG_CONS(formals);
- DBG("\n");
- DBG("actuals: ");
- DBG_CONS(actuals);
- DBG("\n");
-
- /* Process all of the arguments */
- if (actuals) {
- v = actuals->car;
- break;
- }
+ ao_lisp_stack->formals = formal;
+ ao_lisp_stack->formals_tail = formal;
- v = formals->car;
+ DBGI("formals now "); DBG_POLY(ao_lisp_stack->formals); DBG("\n");
- /* Evaluate the resulting list */
- if (ao_lisp_poly_type(v) == AO_LISP_BUILTIN) {
- struct ao_lisp_builtin *b = ao_lisp_poly_builtin(v);
+ ao_lisp_v = ao_lisp_poly_cons(ao_lisp_stack->actuals)->cdr;
- v = ao_lisp_func(b) (ao_lisp_poly_cons(formals->cdr));
+ stack_validate_tails();
+ ao_lisp_stack->state = eval_sexpr;
- DBG ("eval: ");
- DBG_CONS(formals);
- DBG(" -> ");
- DBG_POLY(v);
- DBG ("\n");
+ break;
+ case eval_exec:
+ if (!ao_lisp_stack->formals) {
+ ao_lisp_v = AO_LISP_NIL;
+ ao_lisp_stack->state = eval_val;
+ break;
+ }
+ ao_lisp_v = ao_lisp_poly_cons(ao_lisp_stack->formals)->car;
+ case eval_exec_direct:
+ DBGI("exec: macro %d ", ao_lisp_stack->macro); DBG_POLY(ao_lisp_v); DBG(" formals "); DBG_POLY(ao_lisp_stack->formals); DBG ("\n");
+ if (ao_lisp_poly_type(ao_lisp_v) == AO_LISP_BUILTIN) {
+ stack_validate_tails();
+ struct ao_lisp_builtin *b = ao_lisp_poly_builtin(ao_lisp_v);
+ stack_validate_tails();
+ struct ao_lisp_cons *f = ao_lisp_poly_cons(ao_lisp_poly_cons(ao_lisp_stack->formals)->cdr);
+
+ DBGI(".. builtin formals "); DBG_CONS(f); DBG("\n");
+ stack_validate_tails();
+ if (ao_lisp_stack->macro)
+ ao_lisp_stack->state = eval_sexpr;
+ else
+ ao_lisp_stack->state = eval_val;
+ ao_lisp_stack->macro = 0;
+ ao_lisp_stack->actuals = ao_lisp_stack->formals = ao_lisp_stack->formals_tail = AO_LISP_NIL;
+ ao_lisp_v = ao_lisp_func(b) (f);
+ DBGI("builtin result:"); DBG_POLY(ao_lisp_v); DBG ("\n");
+ if (ao_lisp_exception)
+ goto bail;
+ break;
} else {
- ao_lisp_exception |= AO_LISP_INVALID;
- return AO_LISP_NIL;
+ ao_lisp_v = ao_lisp_lambda(ao_lisp_poly_cons(ao_lisp_stack->formals));
+ ao_lisp_stack_reset(ao_lisp_stack);
}
- done_eval:
- 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 = ao_lisp_poly_cons(frame->cdr);
-
- /* Recompute the tail of the formals list */
- for (formal = formals; formal->cdr != AO_LISP_NIL; formal = ao_lisp_poly_cons(formal->cdr));
- formals_tail = formal;
-
- stack = ao_lisp_poly_cons(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");
+ break;
+ case eval_cond:
+ DBGI("cond: "); DBG_POLY(ao_lisp_stack->actuals); DBG("\n");
+ if (!ao_lisp_stack->actuals) {
+ ao_lisp_v = AO_LISP_NIL;
+ ao_lisp_stack->state = eval_val;
} else {
- DBG("done func\n");
- break;
+ ao_lisp_v = ao_lisp_poly_cons(ao_lisp_stack->actuals)->car;
+ if (!ao_lisp_v || ao_lisp_poly_type(ao_lisp_v) != AO_LISP_CONS) {
+ ao_lisp_error(AO_LISP_INVALID, "invalid cond clause");
+ goto bail;
+ }
+ ao_lisp_v = ao_lisp_poly_cons(ao_lisp_v)->car;
+ ao_lisp_stack->state = eval_cond_test;
+ stack_validate_tails();
+ ao_lisp_stack_push();
+ stack_validate_tails();
+ ao_lisp_stack->state = eval_sexpr;
+ }
+ break;
+ case eval_cond_test:
+ DBGI("cond_test: "); DBG_POLY(ao_lisp_v); DBG(" actuals "); DBG_POLY(ao_lisp_stack->actuals); DBG("\n");
+ if (ao_lisp_v) {
+ struct ao_lisp_cons *car = ao_lisp_poly_cons(ao_lisp_poly_cons(ao_lisp_stack->actuals)->car);
+ struct ao_lisp_cons *c = ao_lisp_poly_cons(car->cdr);
+ if (c) {
+ ao_lisp_v = c->car;
+ ao_lisp_stack->state = eval_sexpr;
+ } else {
+ ao_lisp_stack->state = eval_val;
+ }
+ } else {
+ ao_lisp_stack->actuals = ao_lisp_poly_cons(ao_lisp_stack->actuals)->cdr;
+ DBGI("actuals now "); DBG_POLY(ao_lisp_stack->actuals); DBG("\n");
+ ao_lisp_stack->state = eval_cond;
}
- }
- if (!cons)
break;
+ }
}
- return v;
+bail:
+ ao_lisp_stack_clear();
+ return AO_LISP_NIL;
}
projects / fw / altos / blobdiff