| """Resolve expression inputs from value mappings or context objects.""" |
|
|
| from __future__ import annotations |
|
|
| from collections.abc import Mapping |
| from typing import Any |
|
|
|
|
| def resolve_context( |
| context: Mapping[str, Any] | Any | None, |
| target: Any = None, |
| num_nodes: int | None = None, |
| ) -> tuple[Mapping[str, Any], Any, int | None]: |
| """Resolve values, target observations, and node metadata from a context. |
| |
| A mapping is always interpreted directly as symbol values. Context objects |
| must expose a mapping-valued ``data`` field and may expose ``target`` and |
| ``num_nodes`` metadata. |
| """ |
| if context is None: |
| values: Mapping[str, Any] = {} |
| elif isinstance(context, Mapping): |
| values = context |
| else: |
| candidate = getattr(context, "data", None) |
| if not isinstance(candidate, Mapping): |
| raise TypeError("context must expose mapping-valued data") |
| values = candidate |
|
|
| if num_nodes is None: |
| num_nodes = getattr(context, "num_nodes", None) |
|
|
| if target is None: |
| target = getattr(context, "target", None) |
| if isinstance(target, str) and target in values: |
| target = values[target] |
| return values, target, num_nodes |
|
|
