altos/lisp: have 'while' return the last body value

[fw/altos] / src / lisp / ao_lisp_eval.c

diff --git a/src/lisp/ao_lisp_eval.c b/src/lisp/ao_lisp_eval.c
index 3af567964deab8a4f87d13a26d13425e3508e901..ef521605764fd1d1a013079149d826963ef4d763 100644 (file)
--- a/src/lisp/ao_lisp_eval.c
+++ b/src/lisp/ao_lisp_eval.c
@@ -122,7 +122,8 @@ ao_lisp_stack_push(void)
 static void
 ao_lisp_stack_pop(void)
 {
-       ao_poly prev;
+       ao_poly                 prev;
+       struct ao_lisp_frame    *prev_frame;
 
        if (!ao_lisp_stack)
                return;
@@ -131,10 +132,13 @@ ao_lisp_stack_pop(void)
        ao_lisp_stack_free_list = ao_lisp_stack;
 
        ao_lisp_stack = ao_lisp_poly_stack(prev);
+       prev_frame = ao_lisp_frame_current;
        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_frame_current != prev_frame)
+               ao_lisp_frame_free(prev_frame);
        DBG_OUT();
        DBGI("stack pop\n");
        DBG_FRAMES();
@@ -306,7 +310,6 @@ ao_lisp_eval_formal(void)
                         * 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;
 
                        DBGI(".. start macro\n");
@@ -397,10 +400,11 @@ ao_lisp_eval_exec(void)
                DBGI(".. frame "); DBG_POLY(ao_lisp_frame_poly(ao_lisp_frame_current)); DBG("\n");
                break;
        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();
-               DBGI(".. sexpr "); DBG_POLY(ao_lisp_v); DBG("\n");
+               ao_lisp_stack->state = eval_progn;
+               v = ao_lisp_lambda_eval();
+               ao_lisp_stack->sexprs = v;
+               DBGI(".. sexprs "); DBG_POLY(ao_lisp_stack->sexprs); DBG("\n");
                DBGI(".. frame "); DBG_POLY(ao_lisp_frame_poly(ao_lisp_frame_current)); DBG("\n");
                break;
        }
@@ -438,7 +442,6 @@ ao_lisp_eval_cond(void)
                ao_lisp_stack->state = eval_cond_test;
                if (!ao_lisp_stack_push())
                        return 0;
-               ao_lisp_stack->state = eval_sexpr;
        }
        return 1;
 }
@@ -460,11 +463,11 @@ ao_lisp_eval_cond_test(void)
        DBGI(".. saved frame "); DBG_POLY(ao_lisp_stack->frame); DBG("\n");
        if (ao_lisp_v) {
                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_poly c = car->cdr;
 
                if (c) {
-                       ao_lisp_stack->state = eval_sexpr;
-                       ao_lisp_v = c->car;
+                       ao_lisp_stack->state = eval_progn;
+                       ao_lisp_stack->sexprs = c;
                } else
                        ao_lisp_stack->state = eval_val;
        } else {
@@ -498,6 +501,10 @@ ao_lisp_eval_progn(void)
        } 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 there are more sexprs to do, then come back here, otherwise
+                * return the value of the last one by just landing in eval_sexpr
+                */
                if (ao_lisp_stack->sexprs) {
                        ao_lisp_stack->state = eval_progn;
                        if (!ao_lisp_stack_push())
@@ -518,6 +525,7 @@ ao_lisp_eval_while(void)
        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->values = ao_lisp_v;
        if (!ao_lisp_stack->sexprs) {
                ao_lisp_v = AO_LISP_NIL;
                ao_lisp_stack->state = eval_val;
@@ -526,7 +534,6 @@ ao_lisp_eval_while(void)
                ao_lisp_stack->state = eval_while_test;
                if (!ao_lisp_stack_push())
                        return 0;
-               ao_lisp_stack->state = eval_sexpr;
        }
        return 1;
 }
@@ -542,15 +549,19 @@ ao_lisp_eval_while_test(void)
        DBGI(".. saved frame "); DBG_POLY(ao_lisp_stack->frame); DBG("\n");
 
        if (ao_lisp_v) {
+               ao_lisp_stack->values = 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;
+               ao_lisp_stack->state = eval_progn;
+               ao_lisp_stack->sexprs = ao_lisp_v;
        }
        else
+       {
                ao_lisp_stack->state = eval_val;
+               ao_lisp_v = ao_lisp_stack->values;
+       }
        return 1;
 }
 
@@ -563,6 +574,8 @@ ao_lisp_eval_macro(void)
 {
        DBGI("macro: "); DBG_POLY(ao_lisp_v); DBG(" sexprs "); DBG_POLY(ao_lisp_stack->sexprs); DBG("\n");
 
+       if (ao_lisp_v == AO_LISP_NIL)
+               ao_lisp_abort();
        if (ao_lisp_poly_type(ao_lisp_v) == AO_LISP_CONS) {
                *ao_lisp_poly_cons(ao_lisp_stack->sexprs) = *ao_lisp_poly_cons(ao_lisp_v);
                ao_lisp_v = ao_lisp_stack->sexprs;