import "allocator/arena"; var sym1 = Symbol("123"); var sym2 = Symbol("123"); assert(sym1 !== sym2); var sym3 = Symbol.for("123"); var sym4 = Symbol.for("123"); assert(sym3 === sym4); var key1 = Symbol.keyFor(sym1); var key2 = Symbol.keyFor(sym2); assert(key1 === null); assert(key2 === null); var key3 = Symbol.keyFor(sym3); var key4 = Symbol.keyFor(sym4); assert(key3 == "123"); assert(key3 == key4); assert(Symbol().toString() == "Symbol()"); assert(sym3.toString() == "Symbol(123)"); var hasInstance = Symbol.hasInstance; var isConcatSpreadable = Symbol.isConcatSpreadable; assert(hasInstance.toString() == "Symbol(hasInstance)"); assert(isConcatSpreadable.toString() == "Symbol(isConcatSpreadable)"); Symbol.hasInstance; Symbol.isConcatSpreadable; // ...