IsKeyword returns the keyword token if literal is a keyword, a KEYWORD token if the literal is a future keyword (const, let, class, super, ...), or 0 if the literal is not a keyword.

+=.

&.

&=.

=>.

=.

`.

~.

??.

:.

,.

--.

...

==.

^.

^=.

**.

**=.

>.

>=.

++.

{.

[.

(.

<.

<=.

&&.

||.

-.

*.

*=.

!.

!=.

|.

|=.

.

+.

?.

?.

/=.

%.

%=.

}.

].

).

;.

<<.

<<=.

>>.

>>=.

/.

===.

!==.

-=.

>>>.

>>>=.

Token is the set of lexical tokens in JavaScript (ECMA5).