cannot evaluate at compile time: i

[trtt]

What's this:
    
    
    proc getRating(columnIx: int, n: float): float =
      if columnIx > 5:
        n * 2
      else:
        n / 2
    
    let data = @[
      (1.0, 2.0, 3.0, 4.0, 1.0, 2.0, "A"),
      (2.0, 2.0, 5.0, 4.0, 1.0, 2.0, "B"),
    ]
    
    for entry in data:
      var rating = 0.0
      for i in 0..4:
        var x = entry[i]
        rating += getRating(i, x)
      echo entry[6], " rating: ", $rating
    
    
    Run

t.nim(15, 19) Error: cannot evaluate at compile time: i