import { TokenType, Token, Item, GroupInProgress } from './tokens.js';
import { Pos } from './position.js';
export declare abstract class Scanner implements IterableIterator<Token> {
    readonly pos: Pos;
    readonly synthetic: boolean | undefined;
    charBuffer: string | null;
    tokenBuffer: Token | null;
    delimiters: string;
    constructor(pos: Pos, synthetic?: boolean);
    [Symbol.iterator](): IterableIterator<Token>;
    abstract _peekChar(): string | null;
    abstract _dropChar(): void;
    peekChar(): string | null;
    dropChar(): void;
    shiftChar(): string | null;
    makeToken(start: Pos, type: TokenType, text: string): Token;
    makeGroupInProgress(open: Token, items?: Array<Item>): GroupInProgress;
    mark(): Pos;
    _while(pred: (ch: string | null) => boolean, f: (ch: string | null) => void): void;
    _collectSpace(buf?: string, start?: Pos): Token;
    _punct(type: TokenType): Token;
    _str(q: string, buf: string, isTemplate: boolean): Token;
    templateConstantFragment(): Token | null;
    isSpace(ch: string): boolean;
    isDelimiter(ch: string): boolean;
    addDelimiters(newDelimiters: string): void;
    _atom(start?: Pos, buf?: string): Token;
    _maybeComment(): Token;
    _peek(): Token | null;
    peek(): Token | null;
    drop(): void;
    shift(): Token | null;
    next(): IteratorResult<Token>;
}
export declare class StringScanner extends Scanner {
    readonly input: string;
    index: number;
    constructor(pos: Pos, input: string, synthetic?: boolean);
    _peekChar(): string | null;
    _dropChar(): void;
}