1 files changed, 308 insertions, 60 deletions

diff --git a/src/lisp/ao_lisp_eval.c b/src/lisp/ao_lisp_eval.c
index 6eef1f23..803f1e2e 100644
--- a/src/lisp/ao_lisp_eval.c
+++ b/src/lisp/ao_lisp_eval.c
@@ -14,32 +14,238 @@
 
 #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
 
+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)
 {
@@ -48,7 +254,7 @@ ao_lisp_eval(ao_poly v)
 
 	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);
@@ -57,29 +263,43 @@ ao_lisp_eval(ao_poly v)
 	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_cons(ao_lisp_cons_poly(actuals), formals);
-				stack = ao_lisp_cons_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 */
@@ -95,19 +315,19 @@ ao_lisp_eval(ao_poly v)
 			break;
 		}
 
-		if (!cons)
-			break;
-
-		for (;;) {
+		while (cons) {
 			DBG("add formal: "); DBG_POLY(v); DBG("\n");
 
+			/* 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:
-						v = ao_lisp_func(b)(ao_lisp_poly_cons(actuals->cdr));
-						goto done_eval;
+						formals = actuals;
+						goto eval;
 
 					case AO_LISP_MACRO:
 						v = ao_lisp_func(b)(ao_lisp_poly_cons(actuals->cdr));
@@ -115,15 +335,28 @@ ao_lisp_eval(ao_poly v)
 						DBG(" -> "); DBG_POLY(v);
 						DBG("\n");
 						if (ao_lisp_poly_type(v) != AO_LISP_CONS) {
-							ao_lisp_exception |= AO_LISP_INVALID;
-							return AO_LISP_NIL;
+							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;
+					}
 				}
 			}
 
@@ -150,6 +383,8 @@ ao_lisp_eval(ao_poly v)
 
 			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);
@@ -161,41 +396,54 @@ ao_lisp_eval(ao_poly v)
 				DBG(" -> ");
 				DBG_POLY(v);
 				DBG ("\n");
+				if (ao_lisp_exception)
+					goto bail;
+
+				if (cond)
+					goto restart;
 			} else {
-				ao_lisp_exception |= AO_LISP_INVALID;
+				v = ao_lisp_lambda(formals);
+				if (ao_lisp_exception)
+					goto bail;
 			}
-			if (ao_lisp_exception)
-				return AO_LISP_NIL;
-		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);
-				formals_tail = NULL;
-
-				/* Recompute the tail of the formals list */
-				if (formals) {
-					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");
+			--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 {
 				actuals = 0;
 				formals = 0;
 				formals_tail = 0;
-				DBG("done func\n");
-				break;
+				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;
 }