code: def mask(array, predicates, new_value, ty):
      
      weld_obj = WeldObject(encoder_, decoder_)
  
      array_var = weld_obj.update(array)
      if isinstance(array, WeldObject):
          array_var = array.obj_id
          weld_obj.dependencies[array_var] = array
  
      predicates_var = weld_obj.update(predicates)
      if isinstance(predicates, WeldObject):
          predicates_var = predicates.obj_id
          weld_obj.dependencies[predicates_var] = predicates
  
      if str(ty).startswith("vec"):
          new_value_var = weld_obj.update(new_value)
          if isinstance(new_value, WeldObject):
              new_value_var = new_value.obj_id
              weld_obj.dependencies[new_value_var] = new_value
      else:
          new_value_var = "%s(%s)" % (ty, str(new_value))
  
      weld_template = """
         map(
           zip(%(array)s, %(predicates)s),
           |p: {%(ty)s, bool}| if (p.$1, %(new_value)s, p.$0)
         )
      """
      weld_obj.weld_code = weld_template % {
          "array": array_var,
          "predicates": predicates_var,
          "new_value": new_value_var,
          "ty": ty}
  
      return weld_obj
docs: Returns a new array, with each element in the original array satisfying the
      passed-in predicate set to `new_value`
  
      Args:
          array (WeldObject / Numpy.ndarray): Input array
          predicates (WeldObject / Numpy.ndarray<bool>): Predicate set
          new_value (WeldObject / Numpy.ndarray / str): mask value
          ty (WeldType): Type of each element in the input array
  
      Returns:
          A WeldObject representing this computation