import type FormatAdapter from "./format_adapter";
/**
 * Look up an adapter by its `--format <name>` identifier.
 * @param name - adapter name (e.g. `"json"`)
 * @returns the matching adapter, or undefined
 */
export declare function getAdapterByName(name: string): FormatAdapter<unknown> | undefined;
/**
 * Look up an adapter by file extension (leading dot included or not).
 * @param ext - the file extension, case-insensitive
 * @returns the matching adapter, or undefined
 */
export declare function getAdapterByExtension(ext: string): FormatAdapter<unknown> | undefined;
/**
 * Resolve an adapter from a filename, or fall back to the default
 * JSON adapter. Used by the file wrappers when the caller hasn't
 * passed `--format` explicitly.
 * @param filename - the filename to inspect
 * @returns the matching adapter, or the JSON default
 */
export declare function getAdapterForFile(filename: string): FormatAdapter<unknown>;
/**
 * @returns the names of every registered adapter
 */
export declare function listFormatNames(): string[];