createFromObject<R extends Position> static method

R createFromObject<R extends Position>(Object position, { required CreatePosition<R> to, Coords? type, })

Creates a position of R from position (of R or Iterable<num>).

If position is R and with compatible coordinate type already, then it's returned. Other Position instances are copied as R.

If position is Iterable<num>, then a position instance is created using the factory function to. Supported coordinate value combinations: (x, y), (x, y, z), (x, y, m) and (x, y, z, m).

Use an optional type to explicitely set the coordinate type. If not provided and an iterable has 3 items, then xyz coordinates are assumed.

Otherwise throws FormatException.

Implementation

static R createFromObject<R extends Position>(
  Object position, {
  required CreatePosition<R> to,
  Coords? type,
}) {
  if (position is Position) {
    if (position is R && (type == null || type == position.type)) {
      // position is of R and with compatiable coord type
      return position;
    } else {
      if (type == null) {
        // create a copy with same coordinate values
        return position.copyTo(to);
      } else {
        // create a copy with z and m selected if coord type suggests so
        return to.call(
          x: position.x,
          y: position.y,
          z: type.is3D ? position.z : null,
          m: type.isMeasured ? position.m : null,
        );
      }
    }
  } else if (position is Iterable<num>) {
    // create position from iterable of num values
    return buildPosition(position, to: to, type: type);
  }
  throw invalidCoordinates;
}