Records.. Wasn't Dictionary an ECMA5 proposal or was that just a novel touch in AS3?

[edit: For those who don't know, Dictionary was a type in AS3 that let you use any object reference or string or number as a unique key, with any type of value attached. Garbage collection worked around this so it wasn't a weak reference as long as the dictionary object itself was alive. Think of a Javascript Set except with strongly typed keys of any kind you specified. Errors thrown at compile time. God..I miss that language.]