Expansion Operator

Symbol: ... Expansion operator ... works just like in JavaScript for construction and deconstruction of lists and maps.

Can work in two ways.
Together with value:

...a

or separated:

... a

Example:

= threeNumbers :: 1 2 3

= fiveNumbers :: ...threeNumbers 45

= (:: one ...restNumbers) fiveNumbers

= userFields :

name 'John'

age 13

= user :

id 1

gender 'm'

isAlive true

...userFields

= (: isAlive ...rest) user

console.log rest