export default class SliceReader {
    buf: string;
    rd?: ReadableStream<string> | ReadableStream<Uint8Array>;
    r: number;
    eof: boolean;
    constructor(source: ReadableStream<string> | ReadableStream<Uint8Array> | string | Uint8Array);
    fill(): Promise<void>;
    readSlice(delim: string): string | null;
}