| 1 |  |  | import typing | 
            
                                                        
            
                                    
            
            
                | 2 |  |  |  | 
            
                                                        
            
                                    
            
            
                | 3 |  |  | from typish.classes._subscriptable_type import SubscriptableType | 
            
                                                        
            
                                    
            
            
                | 4 |  |  |  | 
            
                                                        
            
                                    
            
            
                | 5 |  |  |  | 
            
                                                        
            
                                    
            
            
                | 6 |  |  | def is_literal_type(cls: typing.Any) -> bool: | 
            
                                                        
            
                                    
            
            
                | 7 |  |  |     """ | 
            
                                                        
            
                                    
            
            
                | 8 |  |  |     Return whether cls is a Literal type. | 
            
                                                        
            
                                    
            
            
                | 9 |  |  |     :param cls: the type that is to be checked. | 
            
                                                        
            
                                    
            
            
                | 10 |  |  |     :return: True if cls is a Literal type. | 
            
                                                        
            
                                    
            
            
                | 11 |  |  |     """ | 
            
                                                        
            
                                    
            
            
                | 12 |  |  |     from typish.functions._get_simple_name import get_simple_name | 
            
                                                        
            
                                    
            
            
                | 13 |  |  |  | 
            
                                                        
            
                                    
            
            
                | 14 |  |  |     return get_simple_name(cls) == 'Literal' | 
            
                                                        
            
                                    
            
            
                | 15 |  |  |  | 
            
                                                        
            
                                    
            
            
                | 16 |  |  |  | 
            
                                                        
            
                                                                    
                                                                                                        
            
            
                | 17 |  | View Code Duplication | class _LiteralMeta(SubscriptableType): | 
                            
                    |  |  |  | 
                                                                                        
                                                                                     | 
            
                                                        
            
                                    
            
            
                | 18 |  |  |     """ | 
            
                                                        
            
                                    
            
            
                | 19 |  |  |     A Metaclass that exists to serve Literal and alter the __args__ attribute. | 
            
                                                        
            
                                    
            
            
                | 20 |  |  |     """ | 
            
                                                        
            
                                    
            
            
                | 21 |  |  |     def __getattribute__(cls, item): | 
            
                                                        
            
                                    
            
            
                | 22 |  |  |         """ | 
            
                                                        
            
                                    
            
            
                | 23 |  |  |         This method makes sure that __args__ is a tuple, like with | 
            
                                                        
            
                                    
            
            
                | 24 |  |  |         typing.Literal. | 
            
                                                        
            
                                    
            
            
                | 25 |  |  |         :param item: the name of the attribute that is obtained. | 
            
                                                        
            
                                    
            
            
                | 26 |  |  |         :return: the attribute. | 
            
                                                        
            
                                    
            
            
                | 27 |  |  |         """ | 
            
                                                        
            
                                    
            
            
                | 28 |  |  |         if item == '__args__': | 
            
                                                        
            
                                    
            
            
                | 29 |  |  |             try: | 
            
                                                        
            
                                    
            
            
                | 30 |  |  |                 result = SubscriptableType.__getattribute__(cls, item), | 
            
                                                        
            
                                    
            
            
                | 31 |  |  |             except AttributeError: | 
            
                                                        
            
                                    
            
            
                | 32 |  |  |                 # In case of Python 3.5 | 
            
                                                        
            
                                    
            
            
                | 33 |  |  |                 result = tuple() | 
            
                                                        
            
                                    
            
            
                | 34 |  |  |         elif item in ('__origin__', '__name__', '_name'): | 
            
                                                        
            
                                    
            
            
                | 35 |  |  |             result = 'Literal' | 
            
                                                        
            
                                    
            
            
                | 36 |  |  |         else: | 
            
                                                        
            
                                    
            
            
                | 37 |  |  |             result = SubscriptableType.__getattribute__(cls, item) | 
            
                                                        
            
                                    
            
            
                | 38 |  |  |         return result | 
            
                                                        
            
                                    
            
            
                | 39 |  |  |  | 
            
                                                        
            
                                    
            
            
                | 40 |  |  |     def __instancecheck__(self, instance): | 
            
                                                        
            
                                    
            
            
                | 41 |  |  |         return self.__args__ and self.__args__[0] == instance | 
            
                                                        
            
                                    
            
            
                | 42 |  |  |  | 
            
                                                        
            
                                    
            
            
                | 43 |  |  |     def __str__(self): | 
            
                                                        
            
                                    
            
            
                | 44 |  |  |         return '{}[{}]'.format(self.__name__, self.__args__[0]) | 
            
                                                        
            
                                    
            
            
                | 45 |  |  |  | 
            
                                                        
            
                                    
            
            
                | 46 |  |  |     def __subclasscheck__(self, subclass: typing.Any) -> bool: | 
            
                                                        
            
                                    
            
            
                | 47 |  |  |         return is_literal_type(subclass) | 
            
                                                        
            
                                    
            
            
                | 48 |  |  |  | 
            
                                                        
            
                                    
            
            
                | 49 |  |  |  | 
            
                                                        
            
                                                                    
                                                                                                        
            
            
                | 50 |  | View Code Duplication | class LiteralAlias(type, metaclass=_LiteralMeta): | 
                            
                    |  |  |  | 
                                                                                        
                                                                                     | 
            
                                                        
            
                                    
            
            
                | 51 |  |  |     """ | 
            
                                                        
            
                                    
            
            
                | 52 |  |  |     This is a backwards compatible variant of typing.Literal (Python 3.8+). | 
            
                                                        
            
                                    
            
            
                | 53 |  |  |     """ | 
            
                                                        
            
                                    
            
            
                | 54 |  |  |     @staticmethod | 
            
                                                        
            
                                    
            
            
                | 55 |  |  |     def from_literal(literal: typing.Any) -> typing.Type['LiteralAlias']: | 
            
                                                        
            
                                    
            
            
                | 56 |  |  |         """ | 
            
                                                        
            
                                    
            
            
                | 57 |  |  |         Create a LiteralAlias from the given typing.Literal. | 
            
                                                        
            
                                    
            
            
                | 58 |  |  |         :param literal: the typing.Literal type. | 
            
                                                        
            
                                    
            
            
                | 59 |  |  |         :return: a LiteralAlias type. | 
            
                                                        
            
                                    
            
            
                | 60 |  |  |         """ | 
            
                                                        
            
                                    
            
            
                | 61 |  |  |         from typish.functions._get_args import get_args | 
            
                                                        
            
                                    
            
            
                | 62 |  |  |  | 
            
                                                        
            
                                    
            
            
                | 63 |  |  |         args = get_args(literal) | 
            
                                                        
            
                                    
            
            
                | 64 |  |  |         return LiteralAlias[args[0]] if args else LiteralAlias | 
            
                                                        
            
                                    
            
            
                | 65 |  |  |  | 
            
                                                        
            
                                    
            
            
                | 66 |  |  |  | 
            
                                                        
            
                                    
            
            
                | 67 |  |  | # If Literal is available (Python 3.8+), then return that type instead. | 
            
                                                        
            
                                    
            
            
                | 68 |  |  | Literal = getattr(typing, 'Literal', LiteralAlias) | 
            
                                                        
            
                                    
            
            
                | 69 |  |  |  |