import { SyntaxKind, DiagnosticMessage } from './types';
export interface ErrorCallback {
    (message: DiagnosticMessage, pos: number, length: number): void;
}
export declare function stringToToken(s: string): SyntaxKind | undefined;
export declare function tokenToString(t: SyntaxKind): string | undefined;
export declare function isIdentifierStart(ch: number): boolean;
export declare function isIdentifierPart(ch: number): boolean;
export declare function isLineBreak(ch: number): boolean;
export declare function isDigit(ch: number): boolean;
export declare function isOctalDigit(ch: number): boolean;
export declare class Scanner {
    private line;
    private char;
    private pos;
    private end;
    private startPos;
    private tokenPos;
    private text;
    private token;
    private tokenValue;
    private onError?;
    private lineMap;
    constructor(onError?: ErrorCallback);
    private error;
    private speculationHelper;
    lookAhead<T>(callback: () => T): T;
    tryScan<T>(callback: () => T): T;
    private scanHexDigits;
    private scanEscapeSequence;
    private scanString;
    private scanNumber;
    private scanBinaryOrOctalDigits;
    private scanOctalDigits;
    private getIdentifierToken;
    setText(text: string): void;
    scan(): SyntaxKind;
    getLine(): number;
    getChar(): number;
    getCurrentPos(): number;
    /**
     * Absolute start position - including adjacent whitespace
     */
    getStartPos(): number;
    /**
     * Actual start position - excluding adjacent whitespace
     */
    getTokenPos(): number;
    getTokenValue(): string;
    getTokenText(): string;
    getLineMap(): number[];
}