/**
 * Converts a string to camelCase.
 *
 * @example
 * ```ts
 * camelCase('foo-bar');  // 'fooBar'
 * camelCase('FOO_BAR');  // 'fooBar'
 * ```
 */
export declare const camelCase: (str: string) => string;
/**
 * Converts a string to PascalCase.
 *
 * @example
 * ```ts
 * pascalCase('foo-bar');      // 'FooBar'
 * pascalCase('foo123bar');    // 'Foo123Bar'
 * ```
 */
export declare const pascalCase: (str: string) => string;
/**
 * Capitalizes the first character of a string (runtime).
 * For TypeScript literal-type preservation, use `capitalize` instead.
 */
export declare const capitalizeFirstLetter: (string: string) => string;
/**
 * Converts a string to kebab-case.
 *
 * @example
 * ```ts
 * kebabCase('fooBar');         // 'foo-bar'
 * kebabCase('XMLHttpRequest'); // 'xml-http-request'
 * ```
 */
export declare const kebabCase: (str: string) => string;
/**
 * Converts a string to snake_case.
 *
 * @example
 * ```ts
 * snakeCase('fooBar');         // 'foo_bar'
 * snakeCase('XMLHttpRequest'); // 'xml_http_request'
 * ```
 */
export declare const snakeCase: (str: string) => string;
/**
 * Converts a string to Title Case - each word capitalized, separators
 * normalized to single spaces.
 *
 * @example
 * ```ts
 * titleCase('hello world');       // 'Hello World'
 * titleCase('foo-bar_baz');       // 'Foo Bar Baz'
 * ```
 */
export declare const titleCase: (str: string) => string;
/**
 * Converts a string into a URL-friendly slug. More aggressive than
 * `kebabCase` - strips all non-ASCII-word characters.
 *
 * @example
 * ```ts
 * slugify('Hello World!');     // 'hello-world'
 * slugify('Über Café');         // 'uber-cafe'
 * ```
 */
export declare const slugify: (str: string) => string;
/**
 * Capitalizes the first character; preserves TypeScript literal types.
 */
export declare const capitalize: <S extends string>(str: S) => Capitalize<S>;
/**
 * Lower-cases the first character; preserves TypeScript literal types.
 */
export declare const uncapitalize: <S extends string>(str: S) => Uncapitalize<S>;
/**
 * Truncates a string to `maxLength` characters, appending an ellipsis
 * (default `…`) if truncation happened. The ellipsis is included in
 * the final length.
 *
 * @example
 * ```ts
 * truncate('Hello, world!', 8);        // 'Hello, …'
 * truncate('Hello, world!', 8, '...'); // 'Hello...'
 * truncate('Short', 20);               // 'Short'
 * ```
 */
export declare const truncate: (str: string, maxLength: number, ellipsis?: string) => string;
/**
 * Escapes HTML special characters for safe interpolation into markup.
 *
 * @example
 * ```ts
 * escapeHtml('<script>alert(1)</script>');
 * // '&lt;script&gt;alert(1)&lt;/script&gt;'
 * ```
 */
export declare const escapeHtml: (str: string) => string;
/**
 * Escapes characters that have special meaning in a regular expression so the
 * string can be safely embedded as a literal match.
 *
 * @example
 * ```ts
 * new RegExp(escapeRegExp('a.b*c')); // matches the literal "a.b*c"
 * ```
 */
export declare const escapeRegExp: (str: string) => string;
/**
 * Splits a string into words by whitespace, dashes, and underscores.
 * Preserves case; filters out empty segments.
 *
 * @example
 * ```ts
 * words('hello_world-foo bar'); // ['hello', 'world', 'foo', 'bar']
 * ```
 */
export declare const words: (str: string) => string[];
/**
 * Splits a string by line breaks (`\r\n`, `\n`, or `\r`).
 *
 * @example
 * ```ts
 * lines('a\nb\r\nc'); // ['a', 'b', 'c']
 * ```
 */
export declare const lines: (str: string) => string[];