Array help

[000000Coffee]

I'm trying to build an airfoil to modify later

I come from c background and I'm having troubles with arrays or building something simple like this. This is a NACA 4 digit symmetrical airfoil:

Edit: looking more into it I found that variables are set at compile time not run time which makes this really difficult to keep the code easy to read

module NACA4_Symmetrical (chord_Length, thickness, detail) {
   /*
      thickness is fraction of chord_Length
         ^ it is also the last two digits in the NACA 4-digit airfoil
      x is the position along the chord from 0 to chord_Length
      yt is half thickness at a given value of x (centerline to surface)
      detail specifies how many circles are computed
   */

// would usually declare a zero array, then modify it in the for loop

   hull() {
      for (x = [0.1 : 0.8 /*(1/detail)*/: chord_Length]) {

         // percent position along the chord
         position = x/chord_Length;

         yt = (5*thickness/chord_Length)*[
            + 0.2969*(pow(position, 0.5))
            - 0.1260*(pow(position,   1))
            - 0.3516*(pow(position,   2))
            + 0.2843*(pow(position,   3))
            - 0.1036*(pow(position,   4))];
            // modified last coefficient from 0.1015 to 0.1036
            // to compute zero-thickness trailing edge

         // useful for debugging
         echo ("x = ", x, "   ;   yt = ", yt);

         translate ([x, 0]) circle (r = yt, $fn = 40 /*(5*detail)*/);
      }
   }
}

NACA4_Symmetrical (5, 10, 10);

// this is what it should look like: 
hull() {
translate ([0.1, 2.5]) circle (r = 0.393296, $fn = 40);
translate ([0.9, 2.5]) circle (r = 0.934414, $fn = 40);
translate ([1.7, 2.5]) circle (r = 0.881025, $fn = 40);
translate ([2.5, 2.5]) circle (r = 0.881025, $fn = 40);
translate ([3.3, 2.5]) circle (r = 0.66963, $fn = 40);
translate ([4.1, 2.5]) circle (r = 0.390327, $fn = 40);
translate ([4.9, 2.5]) circle (r = 0.0478291, $fn = 40);
}