import { type PartSpan } from "../ir/part-span.js";
import type { Scope } from "./scope.js";
export interface SetOpArm {
    /** The arm's own (select-shaped, or itself a nested set-op) scope. */
    scope: Scope;
    span: PartSpan;
}
export interface SetOpArms {
    /** The whole set-op construct's span. */
    span: PartSpan;
    /** Each arm, flattened left-to-right in source order (nested set-ops folded left). */
    arms: SetOpArm[];
}
/** `undefined` for a non-setop frame, or when a span can't be honestly derived (never fabricate a
 *  partial arm list). Total: never throws. */
export declare function setOpArmsOf(scope: Scope): SetOpArms | undefined;