ES6 - Next Javascript

1. Proper tail call (recursion without using caller scope)
tail call - last instruction should be a fun without using caller scope
close call
tail position
max recursion number ~10,000 in ES5

2. Temporal Temp Zone- trows error

3. google traceur-compiler
https://google.github.io/traceur-compiler/demo/repl.html#
there is cmd tool

4. Rest parameters
fun (a, b, ...rest) {
}

4. Spead operator

5. Distructing object
let {name, age} = obj;
fun({name, age}) {}

5.1 Refutable pattern:
let {name:firstName = 'Unknown', age, ?phone} = user;
let ?{name, age, pone} = user;

#irefutable/refutable  - undeclared, undefined

let ?{x:a=1} = undefined
let {?x:a=1} = {}

5.2 Destructing array
in method signature:  fun([a, b, ...rest]) {}
var [a, b, ?c] = [1,2];
var ?[a, c] = [];

6. Arrow functions