alist defined in a parent context. BASED-ON should always be a tail
of ALIST.
- Push or pop (depending on value of VAL) a single entry from a
+ Push a single entry from a
translator property list by name of PROP. GROB_PROPERTY_PATH
indicates nested alists, eg. '(beamed-stem-lengths details)
+
+ Return value can be passed to matched_pop and will only cancel the
+ same override then.
*/
-void
+SCM
Grob_property_info::push (SCM grob_property_path, SCM new_value)
{
/*
Don't mess with MIDI.
*/
if (!create ())
- return;
+ return SCM_EOL;
SCM symbol = scm_car (grob_property_path);
SCM rest = scm_cdr (grob_property_path);
{
// poor man's typechecking
if (typecheck_grob (symbol, nested_create_alist (rest, new_value))) {
- props_->alist_ = scm_acons (grob_property_path, new_value, props_->alist_);
+ SCM cell = scm_cons (grob_property_path, new_value);
+ props_->alist_ = scm_cons (cell, props_->alist_);
props_->nested_++;
+ return cell;
}
- return;
+ return SCM_EOL;
}
/* it's tempting to replace the head of the list if it's the same
*/
if (typecheck_grob (symbol, new_value))
- props_->alist_ = scm_acons (symbol, new_value, props_->alist_);
+ {
+ SCM cell = scm_cons (symbol, new_value);
+ props_->alist_ = scm_cons (cell, props_->alist_);
+ return cell;
+ }
+ return SCM_EOL;
+}
+
+void
+Grob_property_info::matched_pop (SCM cell)
+{
+ if (!scm_is_pair (cell))
+ return;
+ if (!check ())
+ return;
+ SCM current_alist = props_->alist_;
+ SCM daddy = props_->based_on_;
+ for (SCM p = current_alist; !scm_is_eq (p, daddy); p = scm_cdr (p))
+ {
+ if (scm_is_eq (scm_car (p), cell))
+ {
+ if (scm_is_pair (scm_car (cell)))
+ props_->nested_--;
+ props_->alist_ = partial_list_copy (current_alist, p, scm_cdr (p));
+ return;
+ }
+ }
+ return;
}
/*