Data commit

Task/Loops-Increment-loop-index-within-loop-body/F-Sharp/loops-increment-loop-index-within-loop-body.fs

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+// Well I don't do loops. Nigel Galloway: March 17th., 2019. Let me try to explain where the loopy variables are, for the imperatively constrained.
+// cUL allows me to claim the rather trivial extra credit (commas in the numbers)
+let cUL=let g=System.Globalization.CultureInfo("en-GB") in (fun (n:uint64)->n.ToString("N0",g))
+// fN is primality by trial division
+let fN g=pCache|>Seq.map uint64|>Seq.takeWhile(fun n->n*n<g)|>Seq.forall(fun n->g%n>0UL)
+// unfold is sort of a loop incremented by 1 in this case
+let fG n=Seq.unfold(fun n->Some(n,(n+1UL))) n|>Seq.find(fN)
+// unfold is sort of a loop with fG as an internal loop incremented by the exit value of the internal loop in this case.
+Seq.unfold(fun n->let n=fG n in Some(n,n+n)) 42UL|>Seq.take 42|>Seq.iteri(fun n g->printfn "%2d -> %s"  (n+1) (cUL g))