static pic_value
pic_error_with_exception_handler(pic_state *pic)
{
pic_value handler, thunk;
pic_value stack, exc = pic_ref(pic, "picrin.base", "current-exception-handlers");
pic_get_args(pic, "ll", &handler, &thunk);
stack = pic_call(pic, exc, 0);
return pic_dynamic_bind(pic, exc, pic_cons(pic, handler, stack), thunk);
}
pic_value
pic_raise_continuable(pic_state *pic, pic_value err)
{
pic_value stack, exc = pic_ref(pic, "picrin.base", "current-exception-handlers");
stack = pic_call(pic, exc, 0);
if (pic_nil_p(pic, stack)) {
pic_panic(pic, "no exception handler");
}
return pic_dynamic_bind(pic, exc, pic_cdr(pic, stack), pic_lambda(pic, raise_continuable, 2, pic_car(pic, stack), err));
}
void
pic_raise(pic_state *pic, pic_value err)
{
pic_value stack, exc = pic_ref(pic, "picrin.base", "current-exception-handlers");
stack = pic_call(pic, exc, 0);
if (pic_nil_p(pic, stack)) {
pic_panic(pic, "no exception handler");
}
pic_dynamic_bind(pic, exc, pic_cdr(pic, stack), pic_lambda(pic, raise, 2, pic_car(pic, stack), err));
PIC_UNREACHABLE();
}
pic_value
pic_funcall(pic_state *pic, const char *name, int n, ...)
{
size_t ai = pic_enter(pic);
pic_value proc, r;
va_list ap;
proc = pic_ref(pic, name);
TYPE_CHECK(pic, proc, proc);
va_start(ap, n);
r = pic_vcall(pic, proc, n, ap);
va_end(ap);
pic_leave(pic, ai);
return pic_protect(pic, r);
}
pic_value
pic_start_try(pic_state *pic, PIC_JMPBUF *jmp)
{
struct cont *cont;
pic_value handler;
pic_value var, old_val, new_val;
pic_value in, out;
struct checkpoint *here;
/* call/cc */
cont = pic_alloca_cont(pic);
pic_save_point(pic, cont, jmp);
handler = pic_lambda(pic, native_exception_handler, 1, pic_make_cont(pic, cont));
/* with-exception-handler */
var = pic_ref(pic, "picrin.base", "current-exception-handlers");
old_val = pic_call(pic, var, 0);
new_val = pic_cons(pic, handler, old_val);
in = pic_lambda(pic, dynamic_set, 2, var, new_val);
out = pic_lambda(pic, dynamic_set, 2, var, old_val);
/* dynamic-wind */
pic_call(pic, in, 0); /* enter */
here = pic->cp;
pic->cp = (struct checkpoint *)pic_obj_alloc(pic, sizeof(struct checkpoint), PIC_TYPE_CP);
pic->cp->prev = here;
pic->cp->depth = here->depth + 1;
pic->cp->in = pic_proc_ptr(pic, in);
pic->cp->out = pic_proc_ptr(pic, out);
return pic_cons(pic, pic_obj_value(here), out);
}
