Question about `global` variable declaration

Hi Internals I'm working on my new proposals and I've found weirdness of global variable declaration in zend_language_parser.y. global_var: simple_variable { $$ = zend_ast_create(ZEND_AST_GLOBAL, zend_ast_create(ZEND_AST_VAR, $1)); } ; Above grammer allows something like this... global $$x; global $$$y; global $$$$z; global ${'abc'}; global $$$$$$$$$${random_int(0, PHP_INT_MAX)}; What's the propose of allowing this? And is there anyone out there knowing and using it? If not, should this be changed to allow only T_VARIABLE to make it consistent with static variable declaration? Regards