Another successive enumeration

Applying functions on the n first elements

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let sa = [ 1 .. 10 ]

let iter2 fs xs =
    let apply1thenn fs  = 
        let last = ref Unchecked.defaultof<_>
        let unforget fs = 
            seq { for x in fs do last := x; yield x }
        let rec forever f = seq { yield f; yield! forever f}

        seq { yield! unforget fs
              yield! forever !last} 

    let fs = (apply1thenn fs)
    Seq.zip fs xs |> Seq.iter(fun (f,e) -> f e)

sa |> iter2 [(fun x -> printfn "%A" x); (fun x -> printfn "another %A" x)]

val sa : int list

Full name: Script.sa

val iter2 : fs:seq<('a -> unit)> -> xs:seq<'a> -> unit

Full name: Script.iter2

val fs : seq<('a -> unit)>

val xs : seq<'a>

val apply1thenn : (seq<'b> -> seq<'b>)

val fs : seq<'b>

val last : 'b ref

Multiple items
val ref : value:'T -> 'T ref

Full name: Microsoft.FSharp.Core.Operators.ref

--------------------
type 'T ref = Ref<'T>

Full name: Microsoft.FSharp.Core.ref<_>

module Unchecked

from Microsoft.FSharp.Core.Operators

val defaultof<'T> : 'T

Full name: Microsoft.FSharp.Core.Operators.Unchecked.defaultof

val unforget : (seq<'b> -> seq<'b>)

Multiple items
val seq : sequence:seq<'T> -> seq<'T>

Full name: Microsoft.FSharp.Core.Operators.seq

--------------------
type seq<'T> = System.Collections.Generic.IEnumerable<'T>

Full name: Microsoft.FSharp.Collections.seq<_>

val x : 'b

val forever : ('c -> seq<'c>)

val f : 'c

module Seq

from Microsoft.FSharp.Collections

val zip : source1:seq<'T1> -> source2:seq<'T2> -> seq<'T1 * 'T2>

Full name: Microsoft.FSharp.Collections.Seq.zip

val iter : action:('T -> unit) -> source:seq<'T> -> unit

Full name: Microsoft.FSharp.Collections.Seq.iter

val f : ('a -> unit)

val e : 'a

val x : int

val printfn : format:Printf.TextWriterFormat<'T> -> 'T

Full name: Microsoft.FSharp.Core.ExtraTopLevelOperators.printfn

Raw view Test code New version

More information

Link:	http://fssnip.net/e3
Posted:	12 years ago
Author:	Nicolas2
Tags:	seq , iter