ArrayPartitionFromPrefixMarkers

ArrayPartitionFromPrefixMarkers.js

function ArrayPartitionFromPrefixMarkers(array, start, stop) {
  const partition = []
  let inPartition = false
  for (let i = 0; i < array.length; ++i) {
    const element = array[i]
    // test element for start prefix to determine
    // if we should enter partition view
    if (false == inPartition && start == element.substring(0, start.length)) {
      inPartition = true
    }

    if (inPartition) {
      partition.push(element)
    }

    if (true == inPartition && stop == element.substring(0, stop.length)) {
      partition.push(element)
      break
    }
  }

  return partition
}

const value = () => Math.random().toString('16').slice(2).slice(0, 16)
const elements = [
  `2014-${value()}`,
  `2014-${value()}`,
  `2014-${value()}`,
  `2014-${value()}`,

  `2015-${value()}`,
  `2015-${value()}`,
  `2015-${value()}`,

  `2016-${value()}`,
  `2016-${value()}`,
  `2016-${value()}`,
  `2016-${value()}`,

  `2017-${value()}`,
  `2017-${value()}`,
  `2017-${value()}`,
  `2017-${value()}`,

  `2018-${value()}`,
  `2018-${value()}`,
]

const partition = ArrayPartitionFromPrefixMarkers(elements, '2015', '2018')

console.log(partition)