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

Instead of always returning 'nil', let while return the last body
value.

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

diff --git a/src/lisp/ao_lisp_error.c b/src/lisp/ao_lisp_error.c
index 7ad7b2b523f8cf0fde6c3dc4038f8404b86a66b6..937739e97259701cec8a496fd7d5ea8eae02d2c2 100644 (file)
--- a/src/lisp/ao_lisp_error.c
+++ b/src/lisp/ao_lisp_error.c
@@ -16,23 +16,30 @@
 #include <stdarg.h>
 
 static void
-ao_lisp_error_cons(char *name, struct ao_lisp_cons *cons)
+ao_lisp_error_poly(char *name, ao_poly poly)
 {
        int first = 1;
        printf("\t\t%s(", name);
-       if (cons) {
-               while (cons) {
-                       if (!first)
-                               printf("\t\t         ");
-                       else
-                               first = 0;
-                       ao_lisp_poly_print(cons->car);
-                       printf("\n");
-                       cons = ao_lisp_poly_cons(cons->cdr);
-               }
-               printf("\t\t         )\n");
-       } else
-               printf(")\n");
+       if (ao_lisp_poly_type(poly) == AO_LISP_CONS) {
+               struct ao_lisp_cons *cons = ao_lisp_poly_cons(poly);
+
+               if (cons) {
+                       while (cons) {
+                               if (!first)
+                                       printf("\t\t         ");
+                               else
+                                       first = 0;
+                               ao_lisp_poly_print(cons->car);
+                               printf("\n");
+                               cons = ao_lisp_poly_cons(cons->cdr);
+                       }
+                       printf("\t\t         )\n");
+               } else
+                       printf(")\n");
+       } else {
+               ao_lisp_poly_print(poly);
+               printf("\n");
+       }
 }
 
 static void tabs(int indent)
@@ -87,8 +94,8 @@ ao_lisp_stack_print(void)
                printf("\t\texpr:   "); ao_lisp_poly_print(s->list); printf("\n");
                printf("\t\tstate:  %s\n", state_names[s->state]);
 //             printf("\t\tmacro:  %s\n", s->macro ? "true" : "false");
-               ao_lisp_error_cons ("sexprs: ", ao_lisp_poly_cons(s->sexprs));
-               ao_lisp_error_cons ("values: ", ao_lisp_poly_cons(s->values));
+               ao_lisp_error_poly ("sexprs: ", s->sexprs);
+               ao_lisp_error_poly ("values: ", s->values);
                ao_lisp_error_frame(2, "frame:  ", ao_lisp_poly_frame(s->frame));
 //             ao_lisp_error_frame(2, "mframe: ", ao_lisp_poly_frame(s->macro_frame));
                printf("\t]\n");

diff --git a/src/lisp/ao_lisp_eval.c b/src/lisp/ao_lisp_eval.c
index 5fa9e0ad47a25ebbde49557b315ae41fd4e6ff1b..ef521605764fd1d1a013079149d826963ef4d763 100644 (file)
--- a/src/lisp/ao_lisp_eval.c
+++ b/src/lisp/ao_lisp_eval.c
@@ -525,6 +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;
@@ -548,6 +549,7 @@ 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;
                ao_lisp_stack->state = eval_while;
                if (!ao_lisp_stack_push())
@@ -556,7 +558,10 @@ ao_lisp_eval_while_test(void)
                ao_lisp_stack->sexprs = ao_lisp_v;
        }
        else
+       {
                ao_lisp_stack->state = eval_val;
+               ao_lisp_v = ao_lisp_stack->values;
+       }
        return 1;
 }