Function planstate_tree_walker

src/backend/nodes/nodeFuncs.c:4308–4390

* planstate_tree_walker --- walk plan state trees * * The walker has already visited the current node, and so we need only * recurse into any sub-nodes it has. */

 * recurse into any sub-nodes it has.
 */
bool
planstate_tree_walker(PlanState *planstate,
					  bool (*walker) (),
					  void *context)
{
	Plan	   *plan = planstate->plan;
	ListCell   *lc;

	/* Guard against stack overflow due to overly complex plan trees */
	check_stack_depth();

	/* initPlan-s */
	if (planstate_walk_subplans(planstate->initPlan, walker, context))
		return true;

	/* lefttree */
	if (outerPlanState(planstate))
	{
		if (walker(outerPlanState(planstate), context))
			return true;
	}

	/* righttree */
	if (innerPlanState(planstate))
	{
		if (walker(innerPlanState(planstate), context))
			return true;
	}

	/* special child plans */
	switch (nodeTag(plan))
	{
		case T_Append:
			if (planstate_walk_members(((AppendState *) planstate)->appendplans,
									   ((AppendState *) planstate)->as_nplans,
									   walker, context))
				return true;
			break;
		case T_MergeAppend:
			if (planstate_walk_members(((MergeAppendState *) planstate)->mergeplans,
									   ((MergeAppendState *) planstate)->ms_nplans,
									   walker, context))
				return true;
			break;
		case T_BitmapAnd:
			if (planstate_walk_members(((BitmapAndState *) planstate)->bitmapplans,
									   ((BitmapAndState *) planstate)->nplans,
									   walker, context))
				return true;
			break;
		case T_BitmapOr:
			if (planstate_walk_members(((BitmapOrState *) planstate)->bitmapplans,
									   ((BitmapOrState *) planstate)->nplans,
									   walker, context))
				return true;
			break;
		case T_Sequence:
			if (planstate_walk_members(((SequenceState *) planstate)->subplans,