/** What a version shows, and where along the roll its symbols lie. */
import { Edition } from "../model/Edition.js";
import { FeatureOrPatch, HorizontalSpan, NestedFeature } from "../model/Feature.js";
import { AnySymbol } from "../model/Symbol.js";
import { Millimeters } from "../model/Quantity.js";
/**
 * The features carrying the symbol, on whichever copy they sit, those a
 * patch bears included. A carrier the edition holds no feature for is
 * left out.
 * @category Lookups
 */
export declare const carriersOf: (edition: Pick<Edition, 'copies'>, symbol: AnySymbol) => Readonly<NestedFeature>[];
/**
 * The carriers that state a place of their own, which a feature on a patch does not.
 * @category Lookups
 */
export declare const placedCarriersOf: (edition: Pick<Edition, 'copies'>, symbol: AnySymbol) => Readonly<FeatureOrPatch>[];
/**
 * Where along the roll the symbol lies, as its carriers put it, or
 * nothing for a symbol no copy carries.
 *
 * Either end is the median of the carriers' rather than their mean, so
 * that a copy which puts the symbol well away from the rest, torn,
 * stretched or badly aligned there, does not draw it away from where
 * the others agree it lies. Two carriers have the two alike.
 *
 * Only the place is measured. Which track the symbol sits on is not
 * a measurement but a question for a tracker bar, since a note of
 * one pitch sits on exactly one position of a given bar: ask
 * `bar.positionOf`. The carriers cannot answer it, because a copy
 * cut for another system numbers its tracks differently, and one
 * symbol may be carried by copies of both — averaging a red carrier
 * on track 47 with a green one on 45 would give 46, a legal
 * position a semitone away on either bar.
 * @category Lookups
 */
export declare const placeOf: (edition: Pick<Edition, 'copies'>, symbol: AnySymbol) => Readonly<HorizontalSpan> | undefined;
/**
 * Where the symbol begins, as the median onset of its carriers, or nothing for a symbol without a place.
 * @category Lookups
 */
export declare const onsetOf: (edition: Pick<Edition, 'copies'>, symbol: AnySymbol) => Millimeters | undefined;
/**
 * The symbols the version shows: what it and its ancestors insert,
 * each version's deletions striking what it or its ancestors inserted.
 * They are worked out once for each state of the edition, and the list
 * is frozen, since everyone who asks is handed the same one.
 * @category Lookups
 */
export declare const snapshotOf: (edition: Edition, versionId: string) => readonly Readonly<AnySymbol>[];