import { TxIconSource } from '../../icon/src/types';
/**
 * Parses an identifier, or `null` when it is empty or malformed.
 *
 * An unprefixed string is not guessed at. `i-ri-rocket-line` looks like a
 * class and `🚀` looks like an emoji, but `rocket.png` is ambiguous between a
 * file and a nonsense class, and a picker that silently resolves one wrong
 * produces an icon that renders as an empty box with no error anywhere. The
 * one exception is a bare emoji, below, which cannot be anything else.
 */
export declare function parseIconIdentifier(identifier: string | null | undefined): TxIconSource | null;
/** Serializes a source. Returns `''` for a valueless source, which stores as "no icon". */
export declare function formatIconIdentifier(icon: TxIconSource | null | undefined): string;