/**
 * Lexer State
 * Tracks position in source text during tokenization
 */
import type { SourceLocation, TokenType } from '../types.js';
export interface LexerState {
    readonly source: string;
    pos: number;
    line: number;
    column: number;
    baseOffset: number;
    inFrontmatter: boolean;
    /**
     * Type of the token emitted immediately before the one being read, or
     * undefined at the start of input. Maintained by the `tokenize()` loop so
     * readers can branch on the preceding token exactly, rather than
     * re-deriving it from raw characters.
     */
    prevTokenType: TokenType | undefined;
    /**
     * Value of that same token. Needed because DOLLAR is emitted for both the
     * `$` that prefixes a variable name and the self-contained accumulator
     * `$@`, which the type alone cannot tell apart.
     */
    prevTokenValue: string | undefined;
    /**
     * True once the first non-whitespace character has been consumed. Used to
     * detect frontmatter delimiters at actual file start while tolerating
     * leading blank lines, without re-scanning consumed source on every `---`
     * match (see tokenizer.ts).
     */
    sawNonWhitespace: boolean;
}
export declare function createLexerState(source: string, baseLocation?: SourceLocation): LexerState;
export declare function currentLocation(state: LexerState): SourceLocation;
export declare function peek(state: LexerState, offset?: number): string;
export declare function peekString(state: LexerState, length: number): string;
export declare function advance(state: LexerState): string;
export declare function isAtEnd(state: LexerState): boolean;