static struct ao_lisp_cons *read_cons_tail;
static struct ao_lisp_cons *read_stack;
-static ao_poly
-read_item(void)
+static int
+push_read_stack(int cons, int in_quote)
+{
+ if (cons) {
+ read_stack = ao_lisp_cons_cons(ao_lisp_cons_poly(read_cons),
+ ao_lisp_cons_cons(ao_lisp_int_poly(in_quote),
+ read_stack));
+ if (!read_stack)
+ return 0;
+ }
+ read_cons = NULL;
+ read_cons_tail = NULL;
+ return 1;
+}
+
+static int
+pop_read_stack(int cons)
+{
+ int in_quote = 0;
+ if (cons) {
+ read_cons = ao_lisp_poly_cons(read_stack->car);
+ read_stack = ao_lisp_poly_cons(read_stack->cdr);
+ in_quote = ao_lisp_poly_int(read_stack->car);
+ read_stack = ao_lisp_poly_cons(read_stack->cdr);
+ for (read_cons_tail = read_cons;
+ read_cons_tail && read_cons_tail->cdr;
+ read_cons_tail = ao_lisp_poly_cons(read_cons_tail->cdr))
+ ;
+ }
+ return in_quote;
+}
+
+ao_poly
+ao_lisp_read(void)
{
struct ao_lisp_atom *atom;
char *string;
int cons;
+ int in_quote;
ao_poly v;
if (!been_here) {
ao_lisp_root_add(&ao_lisp_cons_type, &read_cons_tail);
ao_lisp_root_add(&ao_lisp_cons_type, &read_stack);
}
+ parse_token = lex();
cons = 0;
+ in_quote = 0;
read_cons = read_cons_tail = read_stack = 0;
for (;;) {
while (parse_token == OPEN) {
- if (cons++)
- read_stack = ao_lisp_cons_cons(ao_lisp_cons_poly(read_cons), read_stack);
- read_cons = NULL;
- read_cons_tail = NULL;
+ if (!push_read_stack(cons, in_quote))
+ return AO_LISP_NIL;
+ cons++;
+ in_quote = 0;
parse_token = lex();
}
else
v = AO_LISP_NIL;
break;
+ case QUOTE:
+ if (!push_read_stack(cons, in_quote))
+ return AO_LISP_NIL;
+ cons++;
+ in_quote = 1;
+ v = _ao_lisp_atom_quote;
+ break;
case CLOSE:
- if (cons)
- v = ao_lisp_cons_poly(read_cons);
- else
+ if (!cons) {
v = AO_LISP_NIL;
- if (--cons) {
- read_cons = ao_lisp_poly_cons(read_stack->car);
- read_stack = ao_lisp_poly_cons(read_stack->cdr);
- for (read_cons_tail = read_cons;
- read_cons_tail && read_cons_tail->cdr;
- read_cons_tail = ao_lisp_poly_cons(read_cons_tail->cdr))
- ;
+ break;
}
+ v = ao_lisp_cons_poly(read_cons);
+ --cons;
+ in_quote = pop_read_stack(cons);
break;
}
- if (!cons)
- break;
+ /* loop over QUOTE ends */
+ for (;;) {
+ if (!cons)
+ return v;
+
+ struct ao_lisp_cons *read = ao_lisp_cons_cons(v, NULL);
+ if (!read)
+ return AO_LISP_NIL;
+
+ if (read_cons_tail)
+ read_cons_tail->cdr = ao_lisp_cons_poly(read);
+ else
+ read_cons = read;
+ read_cons_tail = read;
+
+ if (!in_quote || !read_cons->cdr)
+ break;
- struct ao_lisp_cons *read = ao_lisp_cons_cons(v, NULL);
- if (read_cons_tail)
- read_cons_tail->cdr = ao_lisp_cons_poly(read);
- else
- read_cons = read;
- read_cons_tail = read;
+ v = ao_lisp_cons_poly(read_cons);
+ --cons;
+ in_quote = pop_read_stack(cons);
+ }
parse_token = lex();
}
return v;
}
-
-ao_poly
-ao_lisp_read(void)
-{
- parse_token = lex();
- return read_item();
-}