SequencePool

sequence-pool.js

function SequencePool(start=0, _next=(num)=>num+1) {
    let pool = [start]
    
    function next() {
        let item = pool.pop()
        if (!pool.length) {
            pool.push(_next(item))
        }
        return item
    }

    function recycle(item) {
        pool.push(item)
    }
    
    return {next, recycle}
}

autoIncrement = SequencePool(1)
evenPool = SequencePool(0, (num)=>num+2)
oddPool = SequencePool(1, (num)=>num+2)
negPool = SequencePool(0, (num)=>num-1)
powerOf2Pool = SequencePool(1, (num)=>num * 2)