slimsearch/dist/index.d.ts

Tiny but powerful full-text search engine for browser and Node

type LeafType = "" & {
    readonly __tag: unique symbol;
};
interface RadixTree<T> extends Map<string, T | RadixTree<T>> {
    get(key: LeafType): T | undefined;
    get(key: string): RadixTree<T> | undefined;
    set(key: LeafType, value: T): this;
    set(key: string, value: RadixTree<T>): this;
}
type Entry<T> = [string, T];
type Path<T> = [RadixTree<T>, string][];
type FuzzyResult<T> = [T, number];
type FuzzyResults<T> = Map<string, FuzzyResult<T>>;

interface Iterators<T> {
    ENTRIES: Entry<T>;
    KEYS: string;
    VALUES: T;
}
type Kind<T> = keyof Iterators<T>;
type Result<T, K extends keyof Iterators<T>> = Iterators<T>[K];
type IteratorPath<T> = {
    node: RadixTree<T>;
    keys: string[];
}[];
interface IterableSet<T> {
    _tree: RadixTree<T>;
    _prefix: string;
}
/**
 * @private
 */
declare class TreeIterator<T, K extends Kind<T>> implements Iterator<Result<T, K>> {
    set: IterableSet<T>;
    _type: K;
    _path: IteratorPath<T>;
    constructor(set: IterableSet<T>, type: K);
    next(): IteratorResult<Result<T, K>>;
    dive(): IteratorResult<Result<T, K>>;
    backtrack(): void;
    key(): string;
    value(): T;
    result(): Result<T, K>;
    [Symbol.iterator](): this;
}

/**
 * A class implementing the same interface as a standard JavaScript
 * [`Map`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map)
 * with string keys, but adding support for efficiently searching entries with
 * prefix or fuzzy search. This class is used internally by {@link SearchIndex} as
 * the inverted index data structure. The implementation is a radix tree
 * (compressed prefix tree).
 *
 * Since this class can be of general utility beyond _SlimSearch_, it is
 * exported by the `slimsearch` package and can be imported (or required) as
 * `slimsearch/SearchableMap`.
 *
 * @typeParam Value The type of the values stored in the map.
 */
declare class SearchableMap<Value = any> {
    /**
     * @ignore
     */
    _tree: RadixTree<Value>;
    /**
     * @ignore
     */
    _prefix: string;
    private _size;
    /**
     * The constructor is normally called without arguments, creating an empty
     * map. In order to create a {@link SearchableMap} from an iterable or from an
     * object, check {@link SearchableMap.from} and {@link SearchableMap.fromObject}.
     *
     * The constructor arguments are for internal use, when creating derived
     * mutable views of a map at a prefix.
     */
    constructor(tree?: RadixTree<Value>, prefix?: string);
    /**
     * Creates and returns a mutable view of this {@link SearchableMap}, containing only
     * entries that share the given prefix.
     *
     * ### Usage:
     *
     * ```js
     * const map = new SearchableMap()
     * map.set("unicorn", 1)
     * map.set("universe", 2)
     * map.set("university", 3)
     * map.set("unique", 4)
     * map.set("hello", 5)
     *
     * const uni = map.atPrefix("uni")
     * uni.get("unique") // => 4
     * uni.get("unicorn") // => 1
     * uni.get("hello") // => undefined
     *
     * const univer = map.atPrefix("univer")
     * univer.get("unique") // => undefined
     * univer.get("universe") // => 2
     * univer.get("university") // => 3
     * ```
     *
     * @param prefix  The prefix
     * @return A {@link SearchableMap} representing a mutable view of the original Map at the given prefix
     */
    atPrefix(prefix: string): SearchableMap<Value>;
    /**
     * @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map/clear
     */
    clear(): void;
    /**
     * @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map/delete
     * @param key  Key to delete
     */
    delete(key: string): void;
    /**
     * @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map/entries
     * @return An iterator iterating through `[key, value]` entries.
     */
    entries(): TreeIterator<Value, "ENTRIES">;
    /**
     * @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map/forEach
     * @param fn  Iteration function
     */
    forEach(fn: (key: string, value: Value, map: SearchableMap) => void): void;
    /**
     * Returns a Map of all the entries that have a key within the given edit
     * distance from the search key. The keys of the returned Map are the matching
     * keys, while the values are two-element arrays where the first element is
     * the value associated to the key, and the second is the edit distance of the
     * key to the search key.
     *
     * ### Usage:
     *
     * ```js
     * const map = new SearchableMap()
     * map.set('hello', 'world')
     * map.set('hell', 'yeah')
     * map.set('ciao', 'mondo')
     *
     * // Get all entries that match the key 'hallo' with a maximum edit distance of 2
     * map.fuzzyGet('hallo', 2)
     * // => Map(2) { 'hello' => ['world', 1], 'hell' => ['yeah', 2] }
     *
     * // In the example, the "hello" key has value "world" and edit distance of 1
     * // (change "e" to "a"), the key "hell" has value "yeah" and edit distance of 2
     * // (change "e" to "a", delete "o")
     * ```
     *
     * @param key  The search key
     * @param maxEditDistance  The maximum edit distance (Levenshtein)
     * @return A Map of the matching keys to their value and edit distance
     */
    fuzzyGet(key: string, maxEditDistance: number): FuzzyResults<Value>;
    /**
     * @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map/get
     * @param key  Key to get
     * @return Value associated to the key, or `undefined` if the key is not
     * found.
     */
    get(key: string): Value | undefined;
    /**
     * @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map/has
     * @param key  Key
     * @return True if the key is in the map, false otherwise
     */
    has(key: string): boolean;
    /**
     * @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map/keys
     * @return An `Iterable` iterating through keys
     */
    keys(): TreeIterator<Value, "KEYS">;
    /**
     * @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map/set
     * @param key  Key to set
     * @param value  Value to associate to the key
     * @return The {@link SearchableMap} itself, to allow chaining
     */
    set(key: string, value: Value): this;
    /**
     * @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map/size
     */
    get size(): number;
    /**
     * Updates the value at the given key using the provided function. The function
     * is called with the current value at the key, and its return value is used as
     * the new value to be set.
     *
     * ### Example:
     *
     * ```js
     * // Increment the current value by one
     * searchableMap.update('somekey', (currentValue) => currentValue == null ? 0 : currentValue + 1)
     * ```
     *
     * If the value at the given key is or will be an object, it might not require
     * re-assignment. In that case it is better to use `fetch()`, because it is
     * faster.
     *
     * @param key  The key to update
     * @param fn  The function used to compute the new value from the current one
     * @return The {@link SearchableMap} itself, to allow chaining
     */
    update(key: string, fn: (value: Value | undefined) => Value): this;
    /**
     * Fetches the value of the given key. If the value does not exist, calls the
     * given function to create a new value, which is inserted at the given key
     * and subsequently returned.
     *
     * ### Example:
     *
     * ```js
     * const map = searchableMap.fetch('somekey', () => new Map())
     * map.set('foo', 'bar')
     * ```
     *
     * @param key  The key to update
     * @param initial  A function that creates a new value if the key does not exist
     * @return The existing or new value at the given key
     */
    fetch(key: string, initial: () => Value): Value;
    /**
     * @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map/values
     * @return An `Iterable` iterating through values.
     */
    values(): TreeIterator<Value, "VALUES">;
    /**
     * @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map/@@iterator
     */
    [Symbol.iterator](): TreeIterator<Value, "ENTRIES">;
    /**
     * Creates a {@link SearchableMap} from an `Iterable` of entries
     *
     * @param entries  Entries to be inserted in the {@link SearchableMap}
     * @return A new {@link SearchableMap} with the given entries
     */
    static from<T = any>(entries: Iterable<Entry<T>> | Entry<T>[]): SearchableMap<T>;
    /**
     * Creates a {@link SearchableMap} from the iterable properties of a JavaScript object
     *
     * @param object  Object of entries for the {@link SearchableMap}
     * @return A new {@link SearchableMap} with the given entries
     */
    static fromObject<T = any>(object: Record<string, T>): SearchableMap<T>;
}

declare const WILDCARD: unique symbol;

type LowercaseCombinationOperator = "or" | "and" | "and_not";
type CombinationOperator = LowercaseCombinationOperator | Uppercase<LowercaseCombinationOperator> | Capitalize<LowercaseCombinationOperator>;
type SerializedIndexEntry = Record<string, number>;
/**
 * Parameters of the BM25+ scoring algorithm. Customizing these is almost never
 * necessary, and fine-tuning them requires an understanding of the BM25 scoring
 * model.
 *
 * Some information about BM25 (and BM25+) can be found at these links:
 *
 * - https://en.wikipedia.org/wiki/Okapi_BM25
 * - https://opensourceconnections.com/blog/2015/10/16/bm25-the-next-generation-of-lucene-relevation/
 */
interface BM25Params {
    /** Term frequency saturation point.
     *
     * Recommended values are between `1.2` and `2`. Higher values increase the
     * difference in score between documents with higher and lower term
     * frequencies. Setting this to `0` or a negative value is invalid. Defaults
     * to `1.2`
     */
    k: number;
    /**
     * Length normalization impact.
     *
     * Recommended values are around `0.75`. Higher values increase the weight
     * that field length has on scoring. Setting this to `0` (not recommended)
     * means that the field length has no effect on scoring. Negative values are
     * invalid. Defaults to `0.7`.
     */
    b: number;
    /**
     * BM25+ frequency normalization lower bound (usually called δ).
     *
     * Recommended values are between `0.5` and `1`. Increasing this parameter
     * increases the minimum relevance of one occurrence of a search term
     * regardless of its (possibly very long) field length. Negative values are
     * invalid. Defaults to `0.5`.
     */
    d: number;
}
/**
 * Match information for a search result. It is a key-value object where keys
 * are terms that matched, and values are the list of fields that the term was
 * found in.
 */
type MatchInfo = Record<string, string[]>;
/**
 * Type of the search results. Each search result indicates the document ID, the
 * terms that matched, the match information, the score, and all the stored
 * fields.
 *
 * @typeParam ID  The type of id being indexed.
 * @typeParam Index The type of the documents being indexed.
 */
type SearchResult<ID = any, Index extends Record<string, any> = Record<never, never>> = Index & {
    /**
     * The document ID
     */
    id: ID;
    /**
     * List of document terms that matched. For example, if a prefix search for
     * `"moto"` matches `"motorcycle"`, `terms` will contain `"motorcycle"`.
     */
    terms: string[];
    /**
     * List of query terms that matched. For example, if a prefix search for
     * `"moto"` matches `"motorcycle"`, `queryTerms` will contain `"moto"`.
     */
    queryTerms: string[];
    /**
     * Score of the search results
     */
    score: number;
    /**
     * Match information, see {@link MatchInfo}
     */
    match: MatchInfo;
};
/**
 * Search options to customize the search behavior.
 *
 * @typeParam ID  The type of id being indexed.
 * @typeParam Index The type of the documents being indexed.
 */
interface SearchOptions<ID = any, Index extends Record<string, any> = Record<never, never>> {
    /**
     * Names of the fields to search in. If omitted, all fields are searched.
     */
    fields?: string[];
    /**
     * Function used to filter search results, for example on the basis of stored
     * fields. It takes as argument each search result and should return a boolean
     * to indicate if the result should be kept or not.
     */
    filter?: (result: SearchResult<ID, Index>) => boolean;
    /**
     * Key-value object of field names to boosting values. By default, fields are
     * assigned a boosting factor of 1. If one assigns to a field a boosting value
     * of 2, a result that matches the query in that field is assigned a score
     * twice as high as a result matching the query in another field, all else
     * being equal.
     */
    boost?: Record<string, number>;
    /**
     * Function to calculate a boost factor for each term.
     *
     * This function, if provided, is called for each query term (as split by
     * `tokenize` and processed by `processTerm`). The arguments passed to the
     * function are the query term, the positional index of the term in the query,
     * and the array of all query terms. It is expected to return a numeric boost
     * factor for the term. A factor lower than 1 reduces the importance of the
     * term, a factor greater than 1 increases it. A factor of exactly 1 is
     * neutral, and does not affect the term's importance.
     */
    boostTerm?: (term: string, i: number, terms: string[]) => number;
    /**
     * Relative weights to assign to prefix search results and fuzzy search
     * results. Exact matches are assigned a weight of 1.
     */
    weights?: {
        fuzzy?: number;
        prefix?: number;
    };
    /**
     * Function to calculate a boost factor for documents. It takes as arguments
     * the document ID, and a term that matches the search in that document, and
     * the value of the stored fields for the document (if any).  It should return
     * a boosting factor: a number higher than 1 increases the computed score, a
     * number lower than 1 decreases the score, and a falsy value skips the search
     * result completely.
     */
    boostDocument?: (documentId: ID, term: string, storedFields?: Index) => number;
    /**
     * Controls whether to perform prefix search. It can be a simple boolean, or a
     * function.
     *
     * If a boolean is passed, prefix search is performed if true.
     *
     * If a function is passed, it is called upon search with a search term, the
     * positional index of that search term in the tokenized search query, and the
     * tokenized search query. The function should return a boolean to indicate
     * whether to perform prefix search for that search term.
     */
    prefix?: boolean | ((term: string, index: number, terms: string[]) => boolean);
    /**
     * Controls whether to perform fuzzy search. It can be a simple boolean, or a
     * number, or a function.
     *
     * If a boolean is given, fuzzy search with a default fuzziness parameter is
     * performed if true.
     *
     * If a number higher or equal to 1 is given, fuzzy search is performed, with
     * a maximum edit distance (Levenshtein) equal to the number.
     *
     * If a number between 0 and 1 is given, fuzzy search is performed within a
     * maximum edit distance corresponding to that fraction of the term length,
     * approximated to the nearest integer. For example, 0.2 would mean an edit
     * distance of 20% of the term length, so 1 character in a 5-characters term.
     * The calculated fuzziness value is limited by the `maxFuzzy` option, to
     * prevent slowdown for very long queries.
     *
     * If a function is passed, the function is called upon search with a search
     * term, a positional index of that term in the tokenized search query, and
     * the tokenized search query. It should return a boolean or a number, with
     * the meaning documented above.
     */
    fuzzy?: boolean | number | ((term: string, index: number, terms: string[]) => boolean | number);
    /**
     * Controls the maximum fuzziness when using a fractional fuzzy value.
     * Very high edit distances usually don't produce meaningful results,
     * but can excessively impact search performance.
     *
     * @default 6
     */
    maxFuzzy?: number;
    /**
     * The operand to combine partial results for each term. By default it is
     * "OR", so results matching _any_ of the search terms are returned by a
     * search. If "AND" is given, only results matching _all_ the search terms are
     * returned by a search.
     */
    combineWith?: CombinationOperator;
    /**
     * Function to tokenize the search query. By default, the same tokenizer used
     * for indexing is used also for search.
     */
    tokenize?: (text: string) => string[];
    /**
     * Function to process or normalize terms in the search query. By default, the
     * same term processor used for indexing is used also for search.
     */
    processTerm?: (term: string) => string | string[] | null | undefined | false;
    /**
     * BM25+ algorithm parameters. Customizing these is almost never necessary,
     * and fine-tuning them requires an understanding of the BM25 scoring model. In
     * most cases, it is best to omit this option to use defaults, and instead use
     * boosting to tweak scoring for specific use cases.
     */
    bm25?: BM25Params;
}
/**
 * Configuration options passed to the {@link SearchIndex} constructor
 *
 * @typeParam ID  The type of id being indexed.
 * @typeParam Document  The type of documents being indexed.
 * @typeParam Index The type of the documents being indexed.
 */
interface SearchIndexOptions<ID = any, Document = any, Index extends Record<string, any> = Record<never, never>> {
    /**
     * Names of the document fields to be indexed.
     */
    fields: string[];
    /**
     * Name of the ID field, uniquely identifying a document.
     */
    idField?: string;
    /**
     * Names of fields to store, so that search results would include them. By
     * default none, so results would only contain the id field.
     */
    storeFields?: string[];
    /**
     * Function used to extract the value of each field in documents. By default,
     * the documents are assumed to be plain objects with field names as keys,
     * but by specifying a custom `extractField` function one can completely
     * customize how the fields are extracted.
     *
     * The function takes as arguments the document, and the name of the field to
     * extract from it. It should return the field value as a string.
     */
    extractField?: (document: Document, fieldName: string) => string;
    /**
     * Function used to split a field value into individual terms to be indexed.
     * The default tokenizer separates terms by space or punctuation, but a
     * custom tokenizer can be provided for custom logic.
     *
     * The function takes as arguments string to tokenize, and the name of the
     * field it comes from. It should return the terms as an array of strings.
     * When used for tokenizing a search query instead of a document field, the
     * `fieldName` is undefined.
     */
    tokenize?: (text: string, fieldName?: string) => string[];
    /**
     * Function used to process a term before indexing or search. This can be
     * used for normalization (such as stemming). By default, terms are
     * downcased, and otherwise no other normalization is performed.
     *
     * The function takes as arguments a term to process, and the name of the
     * field it comes from. It should return the processed term as a string, or a
     * falsy value to reject the term entirely.
     *
     * It can also return an array of strings, in which case each string in the
     * returned array is indexed as a separate term.
     */
    processTerm?: (term: string, fieldName?: string) => string | string[] | null | undefined | false;
    /**
     * Function called to log messages. Arguments are a log level ('debug',
     * 'info', 'warn', or 'error'), a log message, and an optional string code
     * that identifies the reason for the log.
     *
     * The default implementation uses `console`, if defined.
     */
    logger?: (level: LogLevel, message: string, code?: string) => void;
    /**
     * If `true` (the default), vacuuming is performed automatically as soon as
     * {@link discard} is called a certain number of times, cleaning up
     * obsolete references from the index. If `false`, no automatic vacuuming is
     * performed. Custom settings controlling auto vacuuming thresholds, as well
     * as batching behavior, can be passed as an object (see the
     * {@link AutoVacuumOptions} type).
     */
    autoVacuum?: boolean | AutoVacuumOptions;
    /**
     * Default search options (see the {@link SearchOptions} type and the
     * {@link search} method for details)
     */
    searchOptions?: SearchOptions<ID, Index>;
    /**
     * Default auto suggest options (see the {@link SearchOptions} type and the
     * {@link autoSuggest} method for details)
     */
    autoSuggestOptions?: SearchOptions<ID, Index>;
}
type LogLevel = "debug" | "info" | "warn" | "error";
/**
 * The type of auto-suggestions
 */
interface Suggestion {
    /**
     * The suggestion
     */
    suggestion: string;
    /**
     * Suggestion as an array of terms
     */
    terms: string[];
    /**
     * Score for the suggestion
     */
    score: number;
}
/**
 * Object format of search index when serialized
 *
 * @typeParam Index The type of the documents being indexed.
 */
interface IndexObject<Index extends Record<string, any> = Record<never, never>> {
    documentCount: number;
    nextId: number;
    documentIds: Record<string, any>;
    fieldIds: Record<string, number>;
    fieldLength: Record<string, number[]>;
    averageFieldLength: number[];
    storedFields: Record<string, Index>;
    dirtCount?: number;
    index: [string, Record<string, SerializedIndexEntry>][];
    version: number;
}
/**
 * @typeParam ID  The type of id being indexed.
 * @typeParam Index The type of the documents being indexed.
 */
interface QueryCombination<ID = any, Index extends Record<string, any> = Record<never, never>> extends SearchOptions<ID, Index> {
    queries: Query[];
}
/**
 * Wildcard query, used to match all terms
 */
type Wildcard = typeof WILDCARD;
/**
 * Search query expression, either a query string or an expression tree
 * combining several queries with a combination of AND or OR.
 */
type Query = QueryCombination | string | Wildcard;
/**
 * Options to control vacuuming behavior.
 *
 * Vacuuming cleans up document references made obsolete by
 * {@link discard} from the index. On large indexes, vacuuming is
 * potentially costly, because it has to traverse the whole inverted index.
 * Therefore, in order to dilute this cost so it does not negatively affects the
 * application, vacuuming is performed in batches, with a delay between each
 * batch. These options are used to configure the batch size and the delay
 * between batches.
 */
interface VacuumOptions {
    /**
     * Size of each vacuuming batch (the number of terms in the index that will be
     * traversed in each batch).
     *
     * @default 1000
     */
    batchSize?: number;
    /**
     * Wait time between each vacuuming batch in milliseconds.
     *
     * @default 10
     */
    batchWait?: number;
}
/**
 * Sets minimum thresholds for `dirtCount` and `dirtFactor` that trigger an
 * automatic vacuuming.
 */
interface VacuumConditions {
    /**
     * Minimum `dirtCount` (number of discarded documents since the last vacuuming)
     * under which auto vacuum is not triggered.
     *
     * @default 20
     */
    minDirtCount?: number;
    /**
     * Minimum `dirtFactor` (proportion of discarded documents over the total)
     * under which auto vacuum is not triggered.
     *
     * @default 0.1
     */
    minDirtFactor?: number;
}
/**
 * Options to control auto vacuum behavior. When discarding a document with
 * {@link discard}, a vacuuming operation is automatically started if the
 * `dirtCount` and `dirtFactor` are above the `minDirtCount` and `minDirtFactor`
 * thresholds defined by this configuration. See {@link VacuumConditions} for
 * details on these.
 *
 * Also, `batchSize` and `batchWait` can be specified, controlling batching
 * behavior (see {@link VacuumOptions}).
 */
type AutoVacuumOptions = VacuumOptions & VacuumConditions;

interface SearchOptionsWithDefaults<ID = any, Index extends Record<string, any> = Record<string, never>> extends SearchOptions<ID, Index> {
    boost: Record<string, number>;
    weights: {
        fuzzy: number;
        prefix: number;
    };
    prefix: boolean | ((term: string, index: number, terms: string[]) => boolean);
    fuzzy: boolean | number | ((term: string, index: number, terms: string[]) => boolean | number);
    maxFuzzy: number;
    combineWith: CombinationOperator;
    bm25: BM25Params;
}
type DocumentTermFrequencies = Map<number, number>;

interface OptionsWithDefaults<ID = any, Document = any, Index extends Record<string, any> = Record<string, never>> extends Omit<SearchIndexOptions<ID, Document, Index>, "processTerm" | "tokenize"> {
    storeFields: string[];
    idField: string;
    extractField: (document: Document, fieldName: string) => string;
    tokenize: (text: string, fieldName: string) => string[];
    processTerm: (term: string, fieldName: string) => string | string[] | null | undefined | false;
    logger: (level: LogLevel, message: string, code?: string) => void;
    autoVacuum: false | AutoVacuumOptions;
    searchOptions: SearchOptionsWithDefaults<ID, Index>;
    autoSuggestOptions: SearchOptions<ID, Index>;
}
type FieldTermData = Map<number, DocumentTermFrequencies>;
/**
 * A class to represent search index
 *
 * ### Basic example:
 *
 * ```js
 * const documents = [
 *   {
 *     id: 1,
 *     title: 'Moby Dick',
 *     text: 'Call me Ishmael. Some years ago...',
 *     category: 'fiction'
 *   },
 *   {
 *     id: 2,
 *     title: 'Zen and the Art of Motorcycle Maintenance',
 *     text: 'I can see by my watch...',
 *     category: 'fiction'
 *   },
 *   {
 *     id: 3,
 *     title: 'Neuromancer',
 *     text: 'The sky above the port was...',
 *     category: 'fiction'
 *   },
 *   {
 *     id: 4,
 *     title: 'Zen and the Art of Archery',
 *     text: 'At first sight it must seem...',
 *     category: 'non-fiction'
 *   },
 *   // ...and more
 * ]
 *
 * // Create a search engine that indexes the 'title' and 'text' fields for
 * // full-text search. Search results will include 'title' and 'category' (plus the
 * // id field, that is always stored and returned)
 * const searchIndex = createIndex({
 *   fields: ['title', 'text'],
 *   storeFields: ['title', 'category']
 * })
 *
 * // Add documents to the index
 * addAll(searchIndex, documents)
 *
 * // Search for documents:
 * const results = search(searchIndex, 'zen art motorcycle')
 * // => [
 * //   { id: 2, title: 'Zen and the Art of Motorcycle Maintenance', category: 'fiction', score: 2.77258 },
 * //   { id: 4, title: 'Zen and the Art of Archery', category: 'non-fiction', score: 1.38629 }
 * // ]
 * ```
 *
 * @typeParam ID  The id type of the documents being indexed.
 * @typeParam Document  The type of the documents being indexed.
 * @typeParam Index The type of the documents being indexed.
 *
 */
declare class SearchIndex<ID = any, Document = any, Index extends Record<string, any> = Record<never, never>> {
    /**
     * @ignore
     */
    _options: OptionsWithDefaults<ID, Document, Index>;
    /**
     * @ignore
     */
    _index: SearchableMap<FieldTermData>;
    /**
     * @ignore
     */
    _documentCount: number;
    /**
     * @ignore
     */
    _documentIds: Map<number, ID>;
    /**
     * @ignore
     */
    _idToShortId: Map<ID, number>;
    /**
     * @ignore
     */
    _fieldIds: Record<string, number>;
    /**
     * @ignore
     */
    _fieldLength: Map<number, number[]>;
    /**
     * @ignore
     */
    _avgFieldLength: number[];
    /**
     * @ignore
     */
    _nextId: number;
    /**
     * @ignore
     */
    _storedFields: Map<number, Index>;
    /**
     * @ignore
     */
    _dirtCount: number;
    /**
     * @ignore
     */
    _currentVacuum: Promise<void> | null;
    /**
     * @ignore
     */
    _enqueuedVacuum: Promise<void> | null;
    /**
     * @ignore
     */
    _enqueuedVacuumConditions: VacuumConditions | undefined;
    /**
     * @param options The options for the search index
     */
    constructor(options: SearchIndexOptions<ID, Document, Index>);
    /**
     * Is `true` if a vacuuming operation is ongoing, `false` otherwise
     */
    get isVacuuming(): boolean;
    /**
     * The number of documents discarded since the most recent vacuuming
     */
    get dirtCount(): number;
    /**
     * A number between 0 and 1 giving an indication about the proportion of
     * documents that are discarded, and can therefore be cleaned up by vacuuming.
     * A value close to 0 means that the index is relatively clean, while a higher
     * value means that the index is relatively dirty, and vacuuming could release
     * memory.
     */
    get dirtFactor(): number;
    /**
     * Total number of documents available to search
     */
    get documentCount(): number;
    /**
     * Number of terms in the index
     */
    get termCount(): number;
    /**
     * Allows serialization of the index to JSON, to possibly store it and later
     * deserialize it with {@link loadJSONIndex} or {@link loadJSONIndexAsync}.
     *
     * Normally one does not directly call this method, but rather call the
     * standard JavaScript `JSON.stringify()` passing the {@link SearchIndex} instance,
     * and JavaScript will internally call this method. Upon deserialization, one
     * must pass to {@link loadJSONIndex} or {@link loadJSONIndexAsync} the same options used to create the original
     * instance that was serialized.
     *
     * ### Usage:
     *
     * ```js
     * // Serialize the index:
     * let searchIndex = createIndex({ fields: ['title', 'text'] })
     * addAll(searchIndex, documents)
     * const json = JSON.stringify(index)
     *
     * // Later, to deserialize it:
     * searchIndex = loadJSONIndex(json, { fields: ['title', 'text'] })
     * ```
     *
     * @return A plain-object serializable representation of the search index.
     */
    toJSON(): IndexObject<Index>;
    /**
     * @ignore
     */
    private addFields;
}

/**
 * Adds a document to the index
 *
 * @typeParam ID  The id type of the documents being indexed.
 * @typeParam Document  The type of the documents being indexed.
 * @typeParam Index The type of the documents being indexed.
 *
 * @param searchIndex  The search index
 * @param document  The document to be indexed
 */
declare const add: <ID, Document, Index extends Record<string, any> = Record<never, never>>(searchIndex: SearchIndex<ID, Document, Index>, document: Document) => void;
/**
 * Adds all the given documents to the index
 *
 * @typeParam ID  The id type of the documents being indexed.
 * @typeParam Document  The type of the documents being indexed.
 * @typeParam Index The type of the documents being indexed.
 *
 * @param searchIndex  The search index
 * @param documents  An array of documents to be indexed
 */
declare const addAll: <ID, Document, Index extends Record<string, any> = Record<never, never>>(searchIndex: SearchIndex<ID, Document, Index>, documents: readonly Document[]) => void;
/**
 * Adds all the given documents to the index asynchronously.
 *
 * Returns a promise that resolves (to `undefined`) when the indexing is done.
 * This method is useful when index many documents, to avoid blocking the main
 * thread. The indexing is performed asynchronously and in chunks.
 *
 * @typeParam ID  The id type of the documents being indexed.
 * @typeParam Document  The type of the documents being indexed.
 * @typeParam Index The type of the documents being indexed.
 *
 * @param searchIndex  The search index
 * @param documents  An array of documents to be indexed
 * @param options  Configuration options
 * @return A promise resolving when the indexing is done
 */
declare const addAllAsync: <ID, Document, Index extends Record<string, any> = Record<never, never>>(searchIndex: SearchIndex<ID, Document, Index>, documents: readonly Document[], options?: {
    chunkSize?: number;
}) => Promise<void>;

/**
 * Provide suggestions for the given search query
 *
 * The result is a list of suggested modified search queries, derived from the
 * given search query, each with a relevance score, sorted by descending score.
 *
 * By default, it uses the same options used for search, except that by
 * default it performs prefix search on the last term of the query, and
 * combine terms with `'AND'` (requiring all query terms to match). Custom
 * options can be passed as a second argument. Defaults can be changed by
 * passing an `autoSuggestOptions` option when initializing the index.
 *
 * ### Basic usage:
 *
 * ```js
 * // Get suggestions for 'neuro':
 * autoSuggest(searchIndex, 'neuro')
 * // => [ { suggestion: 'neuromancer', terms: [ 'neuromancer' ], score: 0.46240 } ]
 * ```
 *
 * ### Multiple words:
 *
 * ```js
 * // Get suggestions for 'zen ar':
 * autoSuggest(searchIndex, 'zen ar')
 * // => [
 * //  { suggestion: 'zen archery art', terms: [ 'zen', 'archery', 'art' ], score: 1.73332 },
 * //  { suggestion: 'zen art', terms: [ 'zen', 'art' ], score: 1.21313 }
 * // ]
 * ```
 *
 * ### Fuzzy suggestions:
 *
 * ```js
 * // Correct spelling mistakes using fuzzy search:
 * autoSuggest(searchIndex, 'neromancer', { fuzzy: 0.2 })
 * // => [ { suggestion: 'neuromancer', terms: [ 'neuromancer' ], score: 1.03998 } ]
 * ```
 *
 * ### Filtering:
 *
 * ```js
 * // Get suggestions for 'zen ar', but only within the 'fiction' category
 * // (assuming that 'category' is a stored field):
 * autoSuggest(searchIndex, 'zen ar', {
 *   filter: (result) => result.category === 'fiction'
 * })
 * // => [
 * //  { suggestion: 'zen archery art', terms: [ 'zen', 'archery', 'art' ], score: 1.73332 },
 * //  { suggestion: 'zen art', terms: [ 'zen', 'art' ], score: 1.21313 }
 * // ]
 * ```
 *
 * @typeParam ID  The id type of the documents being indexed.
 * @typeParam Document  The type of the documents being indexed.
 * @typeParam Index The type of the documents being indexed.
 *
 * @param searchIndex The search index
 * @param queryString  Query string to be expanded into suggestions
 * @param options  Search options. The supported options and default values
 * are the same as for the `search` method, except that by default prefix
 * search is performed on the last term in the query, and terms are combined
 * with `'AND'`.
 * @return  A sorted array of suggestions sorted by relevance score.
 */
declare const autoSuggest: <ID, Document, Index extends Record<string, any> = Record<never, never>>(searchIndex: SearchIndex<ID, Document, Index>, queryString: string, options?: SearchOptions<ID, Index>) => Suggestion[];

/**
 * Returns the default value of an option. It will throw an error if no option
 * with the given name exists.
 *
 * ### Usage:
 *
 * ```js
 * // Get default tokenizer
 * getDefaultValue('tokenize')
 *
 * // Get default term processor
 * getDefaultValue('processTerm')
 *
 * // Unknown options will throw an error
 * getDefaultValue('notExisting')
 * // => throws 'SlimSearch: unknown option "notExisting"'
 * ```
 *
 * @typeParam ID  The id type of the documents being indexed.
 * @typeParam Document  The type of the documents being indexed.
 * @typeParam Index The type of the documents being indexed.
 *
 * @param optionName  Name of the option
 * @return The default value of the given option
 */
declare const getDefaultValue: (optionName: string) => unknown;

/**
 * Returns `true` if a document with the given ID is present in the index and
 * available for search, `false` otherwise
 *
 * @typeParam ID  The id type of the documents being indexed.
 * @typeParam Document  The type of the documents being indexed.
 * @typeParam Index The type of the documents being indexed.
 *
 * @param searchIndex The search index
 * @param id  The document ID
 */
declare const has: <ID, Document, Index extends Record<string, any> = Record<never, never>>(searchIndex: SearchIndex<ID, Document, Index>, id: ID) => boolean;
/**
 * Returns the stored fields (as configured in the `storeFields` constructor
 * option) for the given document ID. Returns `undefined` if the document is
 * not present in the index.
 *
 * @typeParam ID  The id type of the documents being indexed.
 * @typeParam Document  The type of the documents being indexed.
 * @typeParam Index The type of the documents being indexed.
 *
 * @param searchIndex The search index
 * @param id  The document ID
 * @returns The stored document index
 */
declare const getStoredFields: <ID, Document, Index extends Record<string, any> = Record<never, never>>(searchIndex: SearchIndex<ID, Document, Index>, id: ID) => Index | undefined;

/**
 * Create search index with given options
 *
 * @typeParam ID  The id type of the documents being indexed.
 * @typeParam Document  The type of the documents being indexed.
 * @typeParam Index The type of the documents being indexed.
 *
 * @param options Configuration options
 * @returns A instance of SearchIndex with given options
 *
 * ### Examples:
 *
 * ```js
 * // Create a search engine that indexes the 'title' and 'text' fields of your
 * // documents:
 * const searchIndex = createIndex({ fields: ['title', 'text'] })
 * ```
 *
 * ### ID Field:
 *
 * ```js
 * // Your documents are assumed to include a unique 'id' field, but if you want
 * // to use a different field for document identification, you can set the
 * // 'idField' option:
 * const searchIndex = createIndex({ idField: 'key', fields: ['title', 'text'] })
 * ```
 *
 * ### Options and defaults:
 *
 * ```js
 * // The full set of options (here with their default value) is:
 * const searchIndex = createIndex({
 *   // idField: field that uniquely identifies a document
 *   idField: 'id',
 *
 *   // extractField: function used to get the value of a field in a document.
 *   // By default, it assumes the document is a flat object with field names as
 *   // property keys and field values as string property values, but custom logic
 *   // can be implemented by setting this option to a custom extractor function.
 *   extractField: (document, fieldName) => document[fieldName],
 *
 *   // tokenize: function used to split fields into individual terms. By
 *   // default, it is also used to tokenize search queries, unless a specific
 *   // `tokenize` search option is supplied. When tokenizing an indexed field,
 *   // the field name is passed as the second argument.
 *   tokenize: (string, _fieldName) => string.split(SPACE_OR_PUNCTUATION),
 *
 *   // processTerm: function used to process each tokenized term before
 *   // indexing. It can be used for stemming and normalization. Return a falsy
 *   // value in order to discard a term. By default, it is also used to process
 *   // search queries, unless a specific `processTerm` option is supplied as a
 *   // search option. When processing a term from a indexed field, the field
 *   // name is passed as the second argument.
 *   processTerm: (term, _fieldName) => term.toLowerCase(),
 *
 *   // searchOptions: default search options, see the `search` method for
 *   // details
 *   searchOptions: undefined,
 *
 *   // fields: document fields to be indexed. Mandatory, but not set by default
 *   fields: undefined
 *
 *   // storeFields: document fields to be stored and returned as part of the
 *   // search results.
 *   storeFields: []
 * })
 * ```
 */
declare const createIndex: <ID, Document, Index extends Record<string, any> = Record<never, never>>(options: SearchIndexOptions<ID, Document, Index>) => SearchIndex<ID, Document, Index>;
/**
 * Instantiates a SearchIndex instance from a JS Object.
 * It should be given the same options originally used when serializing the index.
 *
 * ### Usage:
 *
 * ```js
 * // If the index was serialized with:
 * let index = createIndex({ fields: ['title', 'text'] })
 *
 * addAll(index, documents)
 *
 * const json = index.toJSON()
 * // It can later be loaded like this:
 * index = loadJSON(json, { fields: ['title', 'text'] })
 * ```
 *
 * @typeParam ID  The id type of the documents being indexed.
 * @typeParam Document  The type of the documents being indexed.
 * @typeParam Index The type of the documents being indexed.
 *
 * @param indexObject index object
 * @param options  configuration options, same as the constructor
 * @return An instance of SearchIndex deserialized from the given JS object.
 */
declare const loadIndex: <ID, Document, Index extends Record<string, any> = Record<never, never>>(indexObject: IndexObject<Index>, options: SearchIndexOptions<ID, Document, Index>) => SearchIndex<ID, Document, Index>;
/**
 * Async equivalent of {@link loadIndex}
 *
 * This function is an alternative to {@link loadIndex} that returns
 * a promise, and loads the index in batches, leaving pauses between them to avoid
 * blocking the main thread. It tends to be slower than the synchronous
 * version, but does not block the main thread, so it can be a better choice
 * when deserializing very large indexes.
 *
 * @typeParam ID  The id type of the documents being indexed.
 * @typeParam Document  The type of the documents being indexed.
 * @typeParam Index The type of the documents being indexed.
 *
 * @param indexObject index object
 * @param options  configuration options, same as the constructor
 * @return A Promise that will resolve to an instance of MiniSearch deserialized from the given JSON.
 */
declare const loadIndexAsync: <ID, Document, Index extends Record<string, any> = Record<never, never>>(indexObject: IndexObject<Index>, options: SearchIndexOptions<ID, Document, Index>) => Promise<SearchIndex<ID, Document, Index>>;
/**
 * Deserializes a JSON index (serialized with `JSON.stringify(index)`)
 * and instantiates a SearchIndex instance. It should be given the same options
 * originally used when serializing the index.
 *
 * ### Usage:
 *
 * ```js
 * // If the index was serialized with:
 * let index = createIndex({ fields: ['title', 'text'] })
 *
 * addAll(index, documents)
 *
 * const json = JSON.stringify(index)
 * // It can later be deserialized like this:
 * index = loadJSONIndex(json, { fields: ['title', 'text'] })
 * ```
 *
 * @typeParam ID  The id type of the documents being indexed.
 * @typeParam Document  The type of the documents being indexed.
 * @typeParam Index The type of the documents being indexed.
 *
 * @param json  JSON-serialized index
 * @param options  configuration options, same as the constructor
 * @return An instance of SearchIndex deserialized from the given JSON.
 */
declare const loadJSONIndex: <ID, Document, Index extends Record<string, any> = Record<never, never>>(json: string, options: SearchIndexOptions<ID, Document, Index>) => SearchIndex<ID, Document, Index>;
/**
 * Async equivalent of {@link loadJSONIndex}
 *
 * This function is an alternative to {@link loadJSONIndex} that returns
 * a promise, and loads the index in batches, leaving pauses between them to avoid
 * blocking the main thread. It tends to be slower than the synchronous
 * version, but does not block the main thread, so it can be a better choice
 * when deserializing very large indexes.
 *
 * @typeParam ID  The id type of the documents being indexed.
 * @typeParam Document  The type of the documents being indexed.
 * @typeParam Index The type of the documents being indexed.
 *
 * @param json  JSON-serialized index
 * @param options  configuration options, same as the constructor
 * @return A Promise that will resolve to an instance of MiniSearch deserialized from the given JSON.
 */
declare const loadJSONIndexAsync: <ID, Document, Index extends Record<string, any> = Record<never, never>>(json: string, options: SearchIndexOptions<ID, Document, Index>) => Promise<SearchIndex<ID, Document, Index>>;

/**
 * Search for documents matching the given search query.
 *
 * The result is a list of scored document IDs matching the query, sorted by
 * descending score, and each including data about which terms were matched and
 * in which fields.
 *
 * ### Basic usage:
 *
 * ```js
 * // Search for "zen art motorcycle" with default options: terms have to match
 * // exactly, and individual terms are joined with OR
 * search(searchIndex, 'zen art motorcycle')
 * // => [ { id: 2, score: 2.77258, match: { ... } }, { id: 4, score: 1.38629, match: { ... } } ]
 * ```
 *
 * ### Restrict search to specific fields:
 *
 * ```js
 * // Search only in the 'title' field
 * search(searchIndex, 'zen', { fields: ['title'] })
 * ```
 *
 * ### Field boosting:
 *
 * ```js
 * // Boost a field
 * search(searchIndex, 'zen', { boost: { title: 2 } })
 * ```
 *
 * ### Prefix search:
 *
 * ```js
 * // Search for "moto" with prefix search (it will match documents
 * // containing terms that start with "moto" or "neuro")
 * search(searchIndex, 'moto neuro', { prefix: true })
 * ```
 *
 * ### Fuzzy search:
 *
 * ```js
 * // Search for "ismael" with fuzzy search (it will match documents containing
 * // terms similar to "ismael", with a maximum edit distance of 0.2 term.length
 * // (rounded to nearest integer)
 * search(searchIndex, 'ismael', { fuzzy: 0.2 })
 * ```
 *
 * ### Combining strategies:
 *
 * ```js
 * // Mix of exact match, prefix search, and fuzzy search
 * search(searchIndex, 'ismael mob', {
 *  prefix: true,
 *  fuzzy: 0.2
 * })
 * ```
 *
 * ### Advanced prefix and fuzzy search:
 *
 * ```js
 * // Perform fuzzy and prefix search depending on the search term. Here
 * // performing prefix and fuzzy search only on terms longer than 3 characters
 * search(searchIndex, 'ismael mob', {
 *  prefix: term => term.length > 3
 *  fuzzy: term => term.length > 3 ? 0.2 : null
 * })
 * ```
 *
 * ### Combine with AND:
 *
 * ```js
 * // Combine search terms with AND (to match only documents that contain both
 * // "motorcycle" and "art")
 * search(searchIndex, 'motorcycle art', { combineWith: 'AND' })
 * ```
 *
 * ### Combine with AND_NOT:
 *
 * There is also an AND_NOT combinator, that finds documents that match the
 * first term, but do not match any of the other terms. This combinator is
 * rarely useful with simple queries, and is meant to be used with advanced
 * query combinations (see later for more details).
 *
 * ### Filtering results:
 *
 * ```js
 * // Filter only results in the 'fiction' category (assuming that 'category'
 * // is a stored field)
 * search(searchIndex, 'motorcycle art', {
 *   filter: (result) => result.category === 'fiction'
 * })
 * ```
 *
 * ### Wildcard query
 *
 * Searching for an empty string (assuming the default tokenizer) returns no
 * results. Sometimes though, one needs to match all documents, like in a
 * "wildcard" search. This is possible by passing the special value
 * `wildcard` as the query:
 *
 * ```javascript
 * // Return search results for all documents
 * search(index, WILDCARD)
 * ```
 *
 * Note that search options such as `filter` and `boostDocument` are still
 * applied, influencing which results are returned, and their order:
 *
 * ```javascript
 * // Return search results for all documents in the 'fiction' category
 * search(index, WILDCARD, {
 *   filter: (result) => result.category === 'fiction'
 * })
 * ```
 *
 * ### Advanced combination of queries:
 *
 * It is possible to combine different subqueries with OR, AND, and AND_NOT,
 * and even with different search options, by passing a query expression
 * tree object as the first argument, instead of a string.
 *
 * ```js
 * // Search for documents that contain "zen" and ("motorcycle" or "archery")
 * search(searchIndex, {
 *   combineWith: 'AND',
 *   queries: [
 *     'zen',
 *     {
 *       combineWith: 'OR',
 *       queries: ['motorcycle', 'archery']
 *     }
 *   ]
 * })
 *
 * // Search for documents that contain ("apple" or "pear") but not "juice" and
 * // not "tree"
 * search(searchIndex, {
 *   combineWith: 'AND_NOT',
 *   queries: [
 *     {
 *       combineWith: 'OR',
 *       queries: ['apple', 'pear']
 *     },
 *     'juice',
 *     'tree'
 *   ]
 * })
 * ```
 *
 * Each node in the expression tree can be either a string, or an object that
 * supports all `SearchOptions` fields, plus a `queries` array field for
 * subqueries.
 *
 * Note that, while this can become complicated to do by hand for complex or
 * deeply nested queries, it provides a formalized expression tree API for
 * external libraries that implement a parser for custom query languages.
 *
 * @typeParam ID  The id type of the documents being indexed.
 * @typeParam Document  The type of the documents being indexed.
 * @typeParam Index The type of the documents being indexed.
 *
 * @param searchIndex Search Index
 * @param query Search query
 * @param searchOptions Search options. Each option, if not given, defaults to the corresponding value of `searchOptions` given to the constructor, or to the library default.
 */
declare const search: <ID, Document, Index extends Record<string, any> = Partial<Document>>(searchIndex: SearchIndex<ID, Document, Index>, query: Query, searchOptions?: SearchOptions<ID, Index>) => SearchResult<ID, Index>[];

/**
 * Discards the document with the given ID, so it won't appear in sear