/**
 * The enrolment-capability gate: `requires` predicates.
 *
 * A vocab role's `requires` list is the REGISTRY GATE — it decides WHO may fill
 * the role based on the declared enrolment capability (cognition / weight /
 * family / host). It is deliberately NOT part of the routing token: capability
 * never rides the token (S0 invariant 3); it gates enrolment here.
 *
 * Each `requires` entry is a single predicate over one capability field:
 *
 *   predicate = field op value
 *   field     = cognition | weight | family | host
 *   op        = "=" | "==" | "!=" | ">=" | "<=" | ">" | "<"
 *
 * Ordering/numeric operators (`>=`, `<=`, `>`, `<`) apply to `weight` only (the
 * one numeric capability field); the string fields support only `=`/`==`/`!=`.
 * A role with no `requires` (or an empty list) is open to any capability.
 *
 * Match semantics are FAIL-CLOSED for a gate: an absent field fails every
 * positive predicate (`=`,`==`,`>=`,`<=`,`>`,`<`); only `!=` is satisfied by an
 * absent field (the worker's field is provably not the forbidden value). A
 * capability satisfies a role iff it satisfies EVERY predicate.
 */
import type { Capability } from "../protocol/index.ts";
/** The capability fields a `requires` predicate may gate on. */
export declare const REQUIRES_FIELDS: readonly ["cognition", "weight", "family", "host"];
export type RequiresField = (typeof REQUIRES_FIELDS)[number];
export type RequiresOp = "=" | "==" | "!=" | ">=" | "<=" | ">" | "<";
export interface RequiresPredicate {
    readonly field: RequiresField;
    readonly op: RequiresOp;
    /** The compared value: a number for `weight`, a string otherwise. */
    readonly value: string | number;
    /** The original source text, for diagnostics. */
    readonly source: string;
}
/** Raised when a `requires` entry is not a well-formed predicate. */
export declare class RequiresParseError extends Error {
    readonly source: string;
    constructor(source: string, detail: string);
}
/** Parse one `requires` entry into a predicate, or throw {@link RequiresParseError}. */
export declare function parseRequires(source: string): RequiresPredicate;
/** Parse every entry of a role's `requires` list. */
export declare function parseRequiresList(requires: readonly string[] | undefined): RequiresPredicate[];
/** True when `capability` satisfies a single predicate (fail-closed on absent fields). */
export declare function satisfiesPredicate(predicate: RequiresPredicate, capability: Capability): boolean;
/** True when `capability` satisfies EVERY predicate (an empty list is open). */
export declare function satisfiesRequires(predicates: readonly RequiresPredicate[], capability: Capability): boolean;