factorial generators

fsharp.fs

let fTable =
    let rec factorial prev pos = seq {
        let current = prev * pos
        yield current
        yield! factorial current (pos + 1)
    }
    factorial 1 1

fsharp2.fs

let fTable = Seq.initInfinite(fun index -> Seq.reduce (*) [1..(index+1)])

harmony.js

function fTable() {
    var prev = 1;
    var pos = 1;
    for (;;) {
        var current = prev * pos;
        prev = current;
        pos++;
        if (yield current) {
            prev = 1;
            pos = 1;
        }
    }
}

scala.scala

def factorial(prev: BigInt, pos: Int): Stream[BigInt] = {
    val current = prev * pos
    current #:: factorial(current, pos + 1)
}
val fTable = factorial(1, 1)