3 people like it.

Choose while function

A function that is like 'Seq.choose' but stops producing values as soon as the first 'None' value is produced.

 1: 
 2: 
 3: 
 4: 
 5: 
 6: 
 7: 
 8: 
 9: 
10: 

let chooseWhile f (input:seq<_>) = 
  seq { use en = input.GetEnumerator()
        let mutable finished = false
        while not finished do
          if en.MoveNext() then 
            match f en.Current with
            | None -> finished <- true
            | Some v -> yield v
          else  
            finished <- true }
val chooseWhile : f:('a -> 'b option) -> input:seq<'a> -> seq<'b>

Full name: Script.chooseWhile
val f : ('a -> 'b option)
val input : seq<'a>
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 en : System.Collections.Generic.IEnumerator<'a>
System.Collections.Generic.IEnumerable.GetEnumerator() : System.Collections.Generic.IEnumerator<'a>
val mutable finished : bool
val not : value:bool -> bool

Full name: Microsoft.FSharp.Core.Operators.not
System.Collections.IEnumerator.MoveNext() : bool
property System.Collections.Generic.IEnumerator.Current: 'a
union case Option.None: Option<'T>
union case Option.Some: Value: 'T -> Option<'T>
val v : 'b
Raw view Test code New version

More information

Link:http://fssnip.net/7Oz
Posted:8 years ago
Author:Tomas Petricek
Tags: sequences

This web site is created using F# and Suave web server. It is hosted on Azure and the source code is on GitHub. Contributions are welcome!

The first version of fssnip.net has been created by @tomaspetricek back in 2010. This web site is a new, open-source and contribution-friendly version.