/**
 * CSV Detection Utilities
 *
 * Auto-detection of CSV characteristics:
 * - Delimiter detection (comma, tab, semicolon, pipe, etc.)
 * - Line ending detection (LF, CRLF, CR)
 * - Quote character normalization
 *
 * This module is part of the csv/utils subsystem:
 * - detect.ts: Auto-detection of CSV format
 * - row.ts: Row format conversions (RowHashArray, headers)
 * - dynamic-typing.ts: Type coercion (string -> number/boolean/date)
 * - number.ts: Number parsing utilities
 * - generate.ts: Test data generation
 */
/**
 * Escape special regex characters
 */
export declare function escapeRegex(str: string): string;
/**
 * Normalize quote option to { enabled, char } form.
 * Centralizes the quote/false/null handling logic.
 */
export declare function normalizeQuoteOption(option: string | false | null | undefined): {
    enabled: boolean;
    char: string;
};
/**
 * Normalize escape option to { enabled, char } form.
 * Consistent with normalizeQuoteOption API design.
 *
 * @param escapeOption - User's escape option (string, false, null, or undefined)
 * @param quoteChar - The quote character (used as default when escape is undefined)
 * @returns { enabled: boolean, char: string }
 *   - enabled=false, char="" when explicitly disabled (false/null)
 *   - enabled=true, char=quoteChar when undefined (default behavior)
 *   - enabled=true, char=escapeOption when string provided
 */
export declare function normalizeEscapeOption(escapeOption: string | false | null | undefined, quoteChar: string): {
    enabled: boolean;
    char: string;
};
/**
 * Strip UTF-8 BOM (Byte Order Mark) from start of string if present.
 * Excel exports UTF-8 CSV files with BOM (\ufeff).
 *
 * @param input - String to process
 * @returns String without BOM
 */
export declare function stripBom(input: string): string;
/**
 * Check if a string starts with a formula escape character.
 * Used for CSV injection prevention.
 */
export declare function startsWithFormulaChar(str: string): boolean;
/**
 * Detect the line terminator used in a string.
 * Uses quote-aware detection to avoid detecting newlines inside quoted fields.
 *
 * @param input - String to analyze
 * @param quote - Quote character (default: '"')
 * @returns Detected line terminator or '\n' as default
 *
 * @example
 * detectLinebreak('a,b\r\nc,d') // '\r\n'
 * detectLinebreak('a,b\nc,d') // '\n'
 * detectLinebreak('a,b\rc,d') // '\r'
 * detectLinebreak('a,b,c') // '\n' (default)
 * detectLinebreak('"a\nb",c\r\nd') // '\r\n' (ignores newline in quotes)
 */
export declare function detectLinebreak(input: string, quote?: string): string;
/**
 * Auto-detect the delimiter used in a CSV string
 *
 * Algorithm:
 * 1. Sample the first few lines (up to 10) for analysis
 * 2. For each candidate delimiter:
 *    - Count occurrences per line (respecting quotes)
 *    - Check consistency: all lines should have the same count
 *    - Higher count = more fields = better delimiter candidate
 * 3. Choose the delimiter with highest consistent field count
 *
 * Tie-breaking rules (in priority order):
 * 1. Lowest delta (variance) wins - more consistent field counts across lines
 * 2. On delta tie, highest avgFieldCount wins - more fields per row
 * 3. On complete tie, array order wins - first delimiter in delimitersToGuess
 *    (default order: comma, semicolon, tab, pipe)
 *
 * @param input - CSV string to analyze
 * @param quote - Quote character (default: '"')
 * @param delimitersToGuess - Custom list of delimiters to try (default: [",", ";", "\t", "|"])
 * @returns Detected delimiter or first delimiter in list
 *
 * @example
 * detectDelimiter('a,b,c\n1,2,3') // ','
 * detectDelimiter('a;b;c\n1;2;3') // ';'
 * detectDelimiter('a\tb\tc\n1\t2\t3') // '\t'
 * detectDelimiter('a:b:c\n1:2:3', '"', [':']) // ':'
 */
export declare function detectDelimiter(input: string, quote?: string, delimitersToGuess?: string[], comment?: string, skipEmptyLines?: boolean | "greedy"): string;