import { xLuceneTypeConfig } from '@terascope/types';
import BaseType from '../base-type.js';
import { GraphQLType, TypeESMapping, DuckDBTypeConfig } from '../../interfaces.js';
/**
 * A keyword that supports substring matching via n-grams. The base value is
 * an exact `keyword`, and a `tokens` sub-field is analyzed with a custom
 * `ngram_analyzer` that emits fixed 3-character n-grams over digits only.
 *
 * - **ES/OpenSearch mapping:** `{ type: 'keyword', fields: { tokens: { type:
 *   'text', analyzer: 'ngram_analyzer' } } }`, plus the custom `analyzer`
 *   (`ngram_analyzer`) and `tokenizer` (`ngram_tokenizer`, type `ngram`,
 *   `min_gram: 3`, `max_gram: 3`, `token_chars: ['digit']`) definitions.
 * - **GraphQL:** `String`.
 * - **xLucene:** `String`.
 *
 * The tokenizer only grams digit characters, so this is aimed at numeric
 * strings (e.g. phone numbers, account numbers) rather than arbitrary text.
 *
 * @example
 * const config: DataTypeConfig = {
 *     version: 1,
 *     fields: { phone: { type: 'NgramTokens' } }
 * };
 */
export default class NgramTokens extends BaseType {
    toESMapping(): TypeESMapping;
    toGraphQL(): GraphQLType;
    toXlucene(): xLuceneTypeConfig;
    /**
     * The DuckDB column type for this field.
     */
    toDuckDB(): DuckDBTypeConfig;
}
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