drop

Removes the nth element from a list

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// -- | Auxiliary recursive drop function
let rec drop' i l1 p l2 =
    if List.length l2 = List.length l1 - 1 then l2
    else 
        let p = if p = i then p+1  else p 
        drop' i l1 (p+1) (List.append l2 [(List.nth l1 p)])

// -- | Removes the the nth element from list
let drop i l =
    drop' i l 0 [] 

// -- | Use cases
let list = [1..10] 
printfn "%A" drop 0 list
printfn "%A" drop 1 list
printfn "%A" drop (List.length list - 1) list

//Or: let drop n xs = Seq.concat([|Seq.take (n-1) xs; Seq.skip n xs|]);;

val drop' : i:int -> l1:'a list -> p:int -> l2:'a list -> 'a list

Full name: Script.drop'

val i : int

val l1 : 'a list

val p : int

val l2 : 'a list

Multiple items
module List

from Microsoft.FSharp.Collections

--------------------
type List<'T> =
  | ( [] )
  | ( :: ) of Head: 'T * Tail: 'T list
  interface IEnumerable
  interface IEnumerable<'T>
  member Head : 'T
  member IsEmpty : bool
  member Item : index:int -> 'T with get
  member Length : int
  member Tail : 'T list
  static member Cons : head:'T * tail:'T list -> 'T list
  static member Empty : 'T list

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

val length : list:'T list -> int

Full name: Microsoft.FSharp.Collections.List.length

val append : list1:'T list -> list2:'T list -> 'T list

Full name: Microsoft.FSharp.Collections.List.append

val nth : list:'T list -> index:int -> 'T

Full name: Microsoft.FSharp.Collections.List.nth

val drop : i:int -> l:'a list -> 'a list

Full name: Script.drop

val l : 'a list

Multiple items
val list : int list

Full name: Script.list

--------------------
type 'T list = List<'T>

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

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

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

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More information

Link:	http://fssnip.net/oP
Posted:	10 years ago
Author:	Antonio Prestes García
Tags:	list