CODEWITHSUNDEEP
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Keneth
Keneth

Reputation: 61

Function that generates a sequence by from the sequence

How to defined a function that generates a sequence by from the sequence passed as the third argument by taking the number of values passed as the first arguments and applying the the function passed as a second argument to them.

dependingOnPastValues : int -> (int list -> int) -> seq<int> -> seq<int>

The missing past values at the start of the sequence can be considered to be 0.

let dependingOnPastValues (count:int) (fn : int list -> int) (input:seq<int>) : seq<int> = failwith "pseudoRandom not yet implemented!"

Upvotes: 1

Views: 70

Answers (1)

Scott Hutchinson
Scott Hutchinson

Reputation: 1721

How about this:


let dependingOnPastValues numValues mapper seqInput =
    seqInput
    |> Seq.take numValues
    |> mapper

or maybe this:


let dependingOnPastValues numValues mapper seqInput =
    seqInput
    |> Seq.take numValues
    |> Seq.map (fun x -> mapper numValues x)

or perhaps more like this:


let aMapper numValues x =
    x // TODO: do something with x

let dependingOnPastValues numValues mapper seqInput =
    seqInput
    |> Seq.mapi (fun i x -> 
        if i > numValues then
            mapper numValues x
        else 0
        )

let result =
    seq [1;1;2]
    |> dependingOnPastValues 1 aMapper

Upvotes: 3

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