Re: How to iterate over a seq[seq[int]] to keep only columns?

[lux]

I'm a newbie but I think it is very 'Nim' to make an iterator:
    
    
    
    iterator columns*[T](mat: seq[seq[T]]): seq[T] =
      var col = newSeq[T](mat.len)
      for c in 0..<mat[0].len:
        for r in 0..<mat.len:
          col[r] = mat[r][c]
        yield col
    
    
    Run

and then you can do: 
    
    
    let v = @[@[2, 4, 1], @[2, 0, 2], @[1, 1, 2], @[0, 0, 0]]
      for i in columns(v):
        echo i
    
    
    @[2, 2, 1, 0]
    @[4, 0, 1, 0]
    @[1, 2, 2, 0]
    
    
    Run