/**
 * @license
 * Copyright (c) 2025 Handsoncode. All rights reserved.
 */
import { StructuralMetadata } from './buildFunctionDescriptions';
/**
 * Authored structural metadata (parameter optionality, `repeatLastArgs`) for the protected built-in functions
 * (`FunctionRegistry._protectedPlugins`), keyed by canonical id.
 *
 * Protected ids are not registered as ordinary plugins, so they carry no `implementedFunctions` entry for
 * {@link HyperFormula.resolveFunctionMetadata} to read arity/optionality from:
 * - `OFFSET` is transformed at parse time into a cell/range reference and has no plugin at all.
 * - `VERSION` has a plugin (`VersionPlugin`), but it is deliberately excluded from the general registry so it can
 *   never be unregistered; reusing its `implementedFunctions` entry would require importing the protected plugin
 *   into the metadata builders, which this module avoids.
 *
 * Each entry's `parameters.length` SHOULD equal the corresponding `FunctionDoc.parameters.length` in `FUNCTION_DOCS`.
 * A protected id degrades exactly as a plugin-backed one does when the two disagree: this map wins, and
 * `getFunctionDetails` reports these parameters under positional names (`Arg1`, `Arg2`, ...) with a console warning,
 * losing the catalogue's authored names and descriptions. The function itself stays available in both tiers, so keep
 * the invariant true by hand when editing either map to keep the descriptions.
 *
 * Deliberately prototype-less, exactly like `FUNCTION_DOCS`. `HyperFormula.resolveFunctionMetadata` indexes this map
 * with a caller-supplied function id, and with `Object.prototype` in the chain
 * `PROTECTED_FUNCTION_METADATA['toString']` resolves to a function rather than `undefined`. The
 * `FunctionRegistry.functionIsProtected` guard (a `Map` lookup) short-circuits before that read today, so this is
 * hardening rather than a live bug — but it keeps the invariant local to the map instead of resting on the order of
 * the caller's conditions, and makes every lookup here answer only for authored ids.
 */
export declare const PROTECTED_FUNCTION_METADATA: Record<string, StructuralMetadata>;