osrlib.core.validation

Structured rejection reasons returned by pure validators.

Kernel validators (class choice, the ability adjustment step, purchase and equip legality) return lists of Rejection values rather than raising: an illegal choice is an in-fiction refusal, not a programmer error. Session command rejections carry these values verbatim in the CommandResult envelope.

Calling an apply-step with input its validator rejects — applying an illegal adjustment, equipping forbidden armour — is programmer misuse and raises stdlib ValueError, per the errors convention in osrlib.errors.

Rejection

Bases: BaseModel

A structured reason a validator refused an input.

code is dotted snake_case namespaced by subsystem, like event message codes (creation.class.requirements_not_met, items.equip.armour_forbidden). params carries the structured facts a front end needs to render the refusal — never baked English prose.

code instance-attribute

code: str

params class-attribute instance-attribute

params: dict[str, int | str | tuple[int | str, ...]] = {}