emca6 infinitely cycle through values in Set using a generator and iterator

lazy-infinite-loop-set.js

"use strict";

// generator to infinitely loop over a set 
let infiniteCycleSet = function* ( set ){
  let _seq = set.values()
  while( true ){
    let _cur = _seq.next()
    if( _cur.done ){
      _seq = set.values()
      _cur = _seq.next()
    }
    yield _cur.value
  }
}

// generator to infinitely loop over a set
// starting from a specific value
let infiniteCycleSetFrom = function* ( set, startAt ){
  let _seq = set.values(), _target = startAt
  while( true ){
    let _cur = _seq.next()
    if( _cur.done ){
      _seq = set.values()
      _cur = _seq.next()
    }
    if( _cur.value === _target ){
      let _next = _seq.next()
      if( _next.done ){
        _seq = set.values()
        _next = _seq.next()
      }
      _target = _next.value
      yield _target
    }
  }
}

// example
let batman = new Set()
batman.add('dunna')
batman.add('nunna')
batman.add('batman!')
batman.add('')

// infiniteCycleSet example
for( let member of infiniteCycleSet( batman ) )
  console.log( member )

dunna
nunna
batman!

dunna
nunna
batman!

dunna
nunna
batman!
.. etc

// infiniteCycleSetFrom example
for( let member of infiniteCycleSetFrom( batman, 'batman!' ) )
  console.log( member )

batman!

dunna
nunna
batman!

dunna
nunna
batman!

dunna
nunna
.. etc