atomref.policy
This module contains the generic resolver that sits below the radii-specific and X–H-specific convenience APIs.
Use it when you want to work directly with the shared value-selection engine:
ValuePolicy— generic element-domain policy configuration,lookup_value(...)— resolve one value together with provenance,get_value(...)— resolve only the numeric value,LookupResult— the structured result object returned by the resolver.
A few practical notes:
- The current runtime supports element-domain scalar policies.
ValuePolicynormalizes element-symbol overrides eagerly.- Transfer sources may be packaged datasets, custom sets, generic policies, or
wrapper policies that expose
as_value_policy(). LookupResult.is_placeholderrefers to the returned numeric value itself, not to whether any transfer happened.LookupResult.transfer_depthcounts how many transfer steps were involved in the returned numeric value.- Nested lookup is cycle-checked across both generic
ValuePolicyobjects and wrapper policies such asRadiiPolicyandXHPolicy.
atomref.policy
Generic value-policy resolution for element-indexed scalar datasets.
LookupResult
dataclass
Result of resolving one value through a policy.
value carries the final scalar value when one could be produced, while
source and the remaining metadata explain how that value was obtained.
transfer_depth counts how many transfer steps were involved in producing
the returned value. Direct base and override values therefore have depth 0.
__float__()
Coerce the resolved value to float or raise if it is missing.
ValuePolicy
dataclass
Bases: Generic[K]
Ordered rule set for resolving element-domain scalar values.
The current runtime resolves only element-domain policies even though the
metadata layer already records a more general domain concept. During
construction, element-domain override keys are normalized to canonical
element symbols and validated as finite floats.
__post_init__()
Validate and normalize policy configuration eagerly.
get_value(symbol, *, policy)
Return only the resolved scalar value for an element-domain policy.
lookup_value(symbol, *, policy)
Public entry point for generic element-domain scalar lookup.
This is the same resolver used internally by the radii convenience layer. In the current implementation the runtime supports only element-domain policies.