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import functools |
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import inspect |
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from typing import Dict, Type, Union, Any, TypeVar, Callable |
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4
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5
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from .interfaces import SpecialDepDefinition |
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from .exceptions import UnresolvableType, DuplicateDefinition |
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from .definitions import normalise |
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UNRESOLVABLE_TYPES = [str, int, float, bool] |
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11
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X = TypeVar("X") |
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DepDefinition = Any |
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class Container: |
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_registered_types: Dict[Type, SpecialDepDefinition] |
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def __init__(self): |
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self._registered_types = {} |
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def define(self, dep: Union[Type[X], Type], resolver: DepDefinition) -> None: |
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if dep in self._registered_types: |
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raise DuplicateDefinition() |
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self._registered_types[dep] = normalise(resolver, self) |
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def resolve(self, dep_type: Type[X], suppress_error=False) -> X: |
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try: |
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if dep_type in UNRESOLVABLE_TYPES: |
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raise UnresolvableType(f"Cannot construct type {dep_type}") |
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registered_type = self._registered_types.get(dep_type, dep_type) |
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return self._build(registered_type) |
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except UnresolvableType as inner_error: |
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if not suppress_error: |
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raise UnresolvableType( |
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f"Cannot construct type {dep_type.__name__}" |
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) from inner_error |
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return None # type: ignore |
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40
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def partial(self, func: Callable[..., X], keys_to_skip=None) -> Callable[..., X]: |
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spec = inspect.getfullargspec(func) |
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bindable_deps = self._infer_dependencies( |
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spec, suppress_error=True, keys_to_skip=keys_to_skip or [] |
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) |
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return functools.partial(func, **bindable_deps) |
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def __getitem__(self, dep: Type[X]) -> X: |
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return self.resolve(dep) |
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def __setitem__(self, dep: Type, resolver: DepDefinition): |
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self.define(dep, resolver) |
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53
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def _build(self, dep_type: Any) -> Any: |
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if isinstance(dep_type, SpecialDepDefinition): |
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return dep_type.get_instance(self._build) |
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56
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return self._reflection_build(dep_type) |
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58
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def _reflection_build(self, dep_type: Type[X]) -> X: |
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spec = inspect.getfullargspec(dep_type.__init__) |
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sub_deps = self._infer_dependencies(spec) |
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return dep_type(**sub_deps) # type: ignore |
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63
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def _infer_dependencies( |
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self, spec: inspect.FullArgSpec, suppress_error=False, keys_to_skip=[] |
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): |
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sub_deps = { |
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key: self.resolve(sub_dep_type, suppress_error=suppress_error) |
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for (key, sub_dep_type) in spec.annotations.items() |
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69
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if key != "return" and sub_dep_type != Any and key not in keys_to_skip |
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} |
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filtered_deps = {key: dep for (key, dep) in sub_deps.items() if dep is not None} |
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return filtered_deps |
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meadsteve /
lagom
