' FB 1.05.0 Win64

#Lang "fblite"

Option Gosub  '' enables Gosub to be used

' Using gosub to simulate a nested function
Function fib(n As UInteger) As UInteger
  Gosub nestedFib
  Exit Function

  nestedFib:
  fib = IIf(n < 2, n, fib(n - 1) + fib(n - 2))
  Return
End Function

' This function simulates (rather messily) gosub by using 2 gotos and would therefore work
' even in the default dialect
Function fib2(n As UInteger) As UInteger
  Goto nestedFib

  exitFib:
  Exit Function

  nestedFib:
  fib2 = IIf(n < 2, n, fib2(n - 1) + fib2(n - 2))
  Goto exitFib
End Function

For i As Integer = 1 To 12
  Print fib(i); " ";
Next

Print

For j As Integer = 1 To 12
  Print fib2(j); " ";
Next

Print
Print "Press any key to quit"
Sleep