/**
 * Breaks an LLM’s streaming token deltas into character, word, or sentence
 * chunks – or lets you plug in your own chunker.
 *
 * Usage
 * -----
 *   const buf = new ChunkBuffer('sentence');
 *   stream.on('delta', d => buf.addToken(d).forEach(pushToUI));
 *   stream.on('end',   () => buf.flush().forEach(pushToUI));
 */
export type ChunkingStrategy = "character" | "word" | "sentence" | ((text: string) => {
    chunks: string[];
    remainder: string;
});
export interface ChunkerOpts {
    /** Flush “words” longer than this (default = 50 chars). */
    maxWordLen?: number;
    /** Force a break after this many chars with no whitespace (default = 400). */
    maxBufferNoBreak?: number;
}
export declare class ChunkBuffer {
    constructor(strategy: ChunkingStrategy, opts?: ChunkerOpts);
    /** Feed one LLM delta; receive zero‑or‑more flushed chunks. */
    addToken(token: string): string[];
    /** Call when the stream closes to emit the final remainder. */
    flush(): string[];
    private buffer;
    private readonly strategy;
    private readonly customChunker?;
    private readonly MAX_WORD_LEN;
    private readonly MAX_BUFFER_NO_BREAK;
    private readonly graphemeSeg?;
    private readonly wordSeg?;
    private readonly sentenceSeg?;
    private flushGraphemes;
    private flushWords;
    private flushSentences;
    private flushLongRuns;
    private flushCustom;
}