Can I use ES6's arrow function syntax with generators? (arrow notation)

Can I use ES6's arrow function syntax with generators?

You can't. Sorry.

According to MDN

The function* statement (function keyword followed by an asterisk) defines a generator function.

From a spec document (my emphasis):

The function syntax is extended to add an optional * token:

FunctionDeclaration: "function" "*"? Identifier "(" FormalParameterList? ")" 
  "{" FunctionBody "}"

The difference between Inline-functions and Arrow-functions

First of all Arrow-functions () => {} are not made to replace Inline-functions function(){} and they are different. Inline-Functions are simply Functions, so the question is what the difference between Arrow-functions and Inline-Functions are.

An arrow function expression (also known as arrow function) has a shorter syntax compared to function expressions and does not bind its own this, arguments, super, or new.target). Arrow functions are always anonymous.

Some more quick details here

---

Why Arrow-function can not be used as generators

https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Functions/Arrow_functions

Use of the yield keyword

The yield keyword may not be used in an arrow function's body (except when permitted within functions further nested within it). As a consequence, arrow functions cannot be used as generators.

Note that generators without yield don't make sense.

---

Why Arrow-function can not use yield

http://tc39wiki.calculist.org/es6/arrow-functions/

Arrow functions bind this lexically, bind return in the Block body case so it returns from the immediately enclosing arrow function, and preclude break and continue from referencing statements outside the immediately enclosing arrow function.

The Identifier primary expression arguments may not be used in an arrow function's body (whether expression or block form).

Likewise, yield may not be used in an arrow function's body. Arrows cannot be generators and we do not want deep continuations.

Yield in an Arrow-Function will throw Semantic Error: http://www.ecma-international.org/

In the End the reason is in the deep complexity in the implementation of ECMA6. C# does not allow this as well for somewhat similar reasons.

In addition to the discussion on esdiscuss.org and the Ecma TC39 committee ES6 meeting notes from November 2013 mentioned above, generator arrows were revisited in two September 2016 ES7 meetings [1] [2]. After a discussion about pros and cons of various syntax (mainly =*> and =>*) and a lack of justifications and use cases for this feature, they came to the conclusion that:

• There is some interest from the committee, but concern that the feature does not pull its weight for adding a new piece of syntax
• Plan to revisit on Day 3 to see if we can get =>* to stage 0 at least, as part of [Domenic Denicola]'s async iteration proposal

The proposal for generator arrows was moved to Stage 1 with Brendan Eich and Domenic Denicola as champions. Asynchronous iteration mentioned above was finished and implemented in 2018.

In Oct 2019 an official repo by Sergey Rubanov appeared with more discussion about syntax and other details.