/**
 * Token-based Chunker
 *
 * Splits text based on token counts using simple tokenization.
 * Best for controlling context window usage with LLMs.
 */
import type { Chunker, Chunk, ChunkerValidationResult, TokenChunkerConfig, BaseChunkerConfig } from "../../types/index.js";
/**
 * Token-aware chunker implementation
 * Splits text based on approximate token counts
 *
 * Note: Uses simple word-based tokenization as approximation.
 * For exact token counts, integrate with tiktoken or model-specific tokenizers.
 */
export declare class TokenChunker implements Chunker {
    readonly strategy: "token";
    private readonly CHARS_PER_TOKEN;
    chunk(text: string, config?: TokenChunkerConfig): Promise<Chunk[]>;
    /**
     * Simple word-based tokenization
     */
    private tokenize;
    /**
     * Get characters per token for a tokenizer
     */
    private getCharsPerToken;
    /**
     * Estimate average tokens per word
     */
    private estimateTokensPerWord;
    /**
     * Estimate token count for text
     */
    estimateTokenCount(text: string, tokenizer?: string): number;
    validateConfig(config: BaseChunkerConfig): ChunkerValidationResult;
}