Iterator
Object with .next(), .send(obj) and .close() methods.
It is iterable via for...of and for...in loops. Both ways act the same, i.e. call .next() repeatedly until it throws a StopIteration.
Generator expression
Iterator created via e.g. (x*2 for (x of array)).
- Can be assigned to a variable (⇒ Generator comprehension),
- used in function call braces to create arguments (e.g.
MyListClass(x for (x of myArray))), - or used with brackets instead of braces, which makes it an Array comprehension (e.g.
var keys = [x for (x in myObject)])
Generator function
Iterator factory created via e.g. function g() { yield 1; yield 2 }.
A call to g() will return a new Iterator.
ECMA 6 Iterable
An object with an .iterator(…) method that returns a generator function. It is iterable via for...of.
JavaScript 1.7 Iterable
An object with an .__iterator__(…) method that returns a generator function. It is iterable via for...in.