Re: spawn & sync woes

[Araq]

Well FlowVarBase is the base class, type it properly and then you can get the 
result back via `^`:
    
    
    import strutils, math, threadpool
    
    proc term(k: float): float = 4 * math.pow(-1, k) / (2*k + 1)
    
    proc computePI(n: int): float =
      var ch = newSeq[FlowVar[float]](n+1)
      for k in 0..n:
        ch[k] = spawn term(float(k))
      for k in 0..n:
        result += ^ch[k]
    
    echo formatFloat(computePI(5000))