[AdamSpeight2008]

Requires a reference to Framework Assembly System.Numerics

Imports System.Numerics

Public Module Numerics

  Public Iterator Function FibonacciSeq() As IEnumerable(of BigInteger)
    Dim n = { BigInteger.Zero, BigInteger.One }
    While True
      Yield n(0)
      n = {n(1),n(0) + n(1) }
    End While
  End Function
  
End Module

Example2

Dim ListOfTheFirst1000 = FibonacciSeq.Take(1000).ToList

Dim Euler2 = FibonacciSeq.TakeWhile(Function(x) x < 4000000).Where(Function(x) x.IsEven).Sum

The Euler2 result relies on the following additional extension method.

Spoiler

Public Module Exts

  <System.Runtime.CompilerServices.Extension>
  Public Function Sum(xs As IEnumerable(of BigInteger )) As BigInteger
    Return xs.Aggregate(Function(p,c) p+c)
  End Function
End Function

[ImpishTendencies]

Hey Im trying to code Fibonacci as a loop in VB 2008 Express edition and the term 'Yield' isn't appearing in blue. Do you have any suggestions as to what I can do. (I've copied from your first example mind you)

[AdamSpeight2008]

Iterators Tutorial
For the loop version isn't that hard, go and think about it.

This post has been edited by AdamSpeight2008: 07 October 2014 - 01:30 PM