altos/scheme: apply also needs to not free value list on lambdas

When apply is invoked on any function, the cons in the argument list
cannot be immediately freed as they have been passed to the
function. That applies to both built-ins as well as lambdas; this
patch removes the special ao_scheme_skip_cons_free global and just
marks the stack in both cases.

Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 4 insertions, 6 deletions

diff --git a/src/scheme/ao_scheme_eval.c b/src/scheme/ao_scheme_eval.c
index 907ecf0b..9204ce1a 100644
--- a/src/scheme/ao_scheme_eval.c
+++ b/src/scheme/ao_scheme_eval.c
@@ -17,7 +17,6 @@
 
 struct ao_scheme_stack		*ao_scheme_stack;
 ao_poly				ao_scheme_v;
-uint8_t				ao_scheme_skip_cons_free;
 
 ao_poly
 ao_scheme_set_cond(struct ao_scheme_cons *c)
@@ -265,7 +264,7 @@ ao_scheme_eval_exec(void)
 				DBGI("set "); DBG_POLY(atom); DBG(" = "); DBG_POLY(val); DBG("\n");
 			});
 		builtin = ao_scheme_poly_builtin(ao_scheme_v);
-		if (builtin && (builtin->args & AO_SCHEME_FUNC_FREE_ARGS) && !ao_scheme_stack_marked(ao_scheme_stack) && !ao_scheme_skip_cons_free) {
+		if (builtin && (builtin->args & AO_SCHEME_FUNC_FREE_ARGS) && !ao_scheme_stack_marked(ao_scheme_stack)) {
 			struct ao_scheme_cons *cons = ao_scheme_poly_cons(ao_scheme_stack->values);
 			ao_scheme_stack->values = AO_SCHEME_NIL;
 			ao_scheme_cons_free(cons);
@@ -294,7 +293,6 @@ ao_scheme_eval_exec(void)
 		DBGI(".. frame "); DBG_POLY(ao_scheme_frame_poly(ao_scheme_frame_current)); DBG("\n");
 		break;
 	}
-	ao_scheme_skip_cons_free = 0;
 	return 1;
 }
 
@@ -325,7 +323,7 @@ ao_scheme_eval_apply(void)
 	ao_scheme_v = ao_scheme_poly_cons(ao_scheme_stack->values)->car;
 	DBGI("apply: "); DBG_POLY(ao_scheme_stack->values); DBG ("\n");
 	ao_scheme_stack->state = eval_exec;
-	ao_scheme_skip_cons_free = 1;
+	ao_scheme_stack_mark(ao_scheme_stack);
 	return 1;
 }
 
@@ -350,7 +348,7 @@ ao_scheme_eval_cond(void)
 		ao_scheme_stack->state = eval_val;
 	} else {
 		ao_scheme_v = ao_scheme_poly_cons(ao_scheme_stack->sexprs)->car;
-		if (!ao_scheme_v || ao_scheme_poly_type(ao_scheme_v) != AO_SCHEME_CONS) {
+		if (!ao_scheme_v || !AO_SCHEME_IS_CONS(ao_scheme_v)) {
 			ao_scheme_error(AO_SCHEME_INVALID, "invalid cond clause");
 			return 0;
 		}
@@ -494,7 +492,7 @@ ao_scheme_eval_macro(void)
 
 	if (ao_scheme_v == AO_SCHEME_NIL)
 		ao_scheme_abort();
-	if (ao_scheme_poly_type(ao_scheme_v) == AO_SCHEME_CONS) {
+	if (AO_SCHEME_IS_CONS(ao_scheme_v)) {
 		*ao_scheme_poly_cons(ao_scheme_stack->sexprs) = *ao_scheme_poly_cons(ao_scheme_v);
 		ao_scheme_v = ao_scheme_stack->sexprs;
 		DBGI("sexprs rewritten to: "); DBG_POLY(ao_scheme_v); DBG("\n");