Returns the best matching implementation from *registry* for type *cls*. Where there is no registered implementation for a specific type, its method resolution order is used to find a more generic implementation. Note: if *registry* does not contain an implementation for the base
(cls, registry)
| 772 | return _c3_mro(cls, abcs=mro) |
| 773 | |
| 774 | def _find_impl(cls, registry): |
| 775 | """Returns the best matching implementation from *registry* for type *cls*. |
| 776 | |
| 777 | Where there is no registered implementation for a specific type, its method |
| 778 | resolution order is used to find a more generic implementation. |
| 779 | |
| 780 | Note: if *registry* does not contain an implementation for the base |
| 781 | *object* type, this function may return None. |
| 782 | |
| 783 | """ |
| 784 | mro = _compose_mro(cls, registry.keys()) |
| 785 | match = None |
| 786 | for t in mro: |
| 787 | if match is not None: |
| 788 | # If *match* is an implicit ABC but there is another unrelated, |
| 789 | # equally matching implicit ABC, refuse the temptation to guess. |
| 790 | if (t in registry and t not in cls.__mro__ |
| 791 | and match not in cls.__mro__ |
| 792 | and not issubclass(match, t)): |
| 793 | raise RuntimeError("Ambiguous dispatch: {} or {}".format( |
| 794 | match, t)) |
| 795 | break |
| 796 | if t in registry: |
| 797 | match = t |
| 798 | return registry.get(match) |
| 799 | |
| 800 | def singledispatch(func): |
| 801 | """Single-dispatch generic function decorator. |
no test coverage detected