type
    Point = tuple
        x:int
        y:int

proc Neighbors(pos:Point):seq[Point]=
    result = @[]
    for offset in @[(0,-1),(0,1),(-1,0),(1,0)]:
        var newPos:Point = pos
        newPos.x = newPos.x + offset[0]
        newPos.y = newPos.y + offset[1]
        result.add(newPos)

for pos in (x:3,y:3).Neighbors():
    echo pos.x # this line fails with: test.nim(16, 13) Error: undeclared field: 'x'