'use strict';

// This file provides access to some of V8's native runtime functions. See

// https://github.com/v8/v8/wiki/Built-in-functions for further information

// about their implementation.

// They have to be loaded before anything else to make sure we deactivate them

// before executing any other code. Gaining access is achieved by using a

// specific flag that is used internally in the startup phase.

// Clone the provided Map Iterator.

function previewMapIterator(it) {

return %MapIteratorClone(it);

}

// Clone the provided Set Iterator.

function previewSetIterator(it) {

return %SetIteratorClone(it);

}

// Retrieve all WeakMap instance key / value pairs up to `max`. `max` limits the

// number of key / value pairs returned. Make sure it is a positive number,

// otherwise V8 aborts. Passing through `0` returns all elements.

function previewWeakMap(weakMap, max) {

return %GetWeakMapEntries(weakMap, max);

}

// Retrieve all WeakSet instance values up to `max`. `max` limits the

// number of key / value pairs returned. Make sure it is a positive number,

// otherwise V8 aborts. Passing through `0` returns all elements.

function previewWeakSet(weakSet, max) {

return %GetWeakSetValues(weakSet, max);

}

module.exports = {

previewMapIterator,

previewSetIterator,

previewWeakMap,

previewWeakSet

};