Function planstate_walk_subplans

src/backend/nodes/nodeFuncs.c:4395–4411

* Walk a list of SubPlans (or initPlans, which also use SubPlan nodes). */

 * Walk a list of SubPlans (or initPlans, which also use SubPlan nodes).
 */
static bool
planstate_walk_subplans(List *plans,
						bool (*walker) (),
						void *context)
{
	ListCell   *lc;

	foreach(lc, plans)
	{
		SubPlanState *sps = lfirst_node(SubPlanState, lc);

		if (walker(sps->planstate, context))
			return true;
	}

	return false;
}

/*
 * Walk the constituent plans of a ModifyTable, Append, MergeAppend,