package ini
Walk will traverse the AST using the v, the Visitor.
func ( []AST,  Visitor) error {
	for ,  := range  {
		switch .Kind {
		case ASTKindExpr,
			ASTKindExprStatement:

			if  := .VisitExpr();  != nil {
				return 
			}
		case ASTKindStatement,
			ASTKindCompletedSectionStatement,
			ASTKindNestedSectionStatement,
			ASTKindCompletedNestedSectionStatement:

			if  := .VisitStatement();  != nil {
				return 
			}
		}
	}

	return nil