Call external objects

External objects are Fib objects that are not defined in the current Fib subobject. These can be from a root-element (root) or from the Fib object database (see section 10 on page ). In this way, parts of Fib objects can be used multiple times in the Fib object or can be reused for different Fib objects.

Syntax:

$$\begin{eqnarray*} Obj &=& obj( Identifier , ( V_1 , \ldots , V_n ) , ( OutVar_{1... ...}, Obj_1), \ldots , ( OutVar_{1}, \ldots ,OutVar_{v_m}, Obj_m) ) \end{eqnarray*}$$

Description of the elements:

• $Identifierer$: Identify (a unique integer) for the Fib object, which is to be used. Only Fib objects that come after the current Fib object should be used (to avoid recursion), in which the Fib objects from the root-elements come first, and then the Fib objects of the database. Of the root-elements, only the root-elements are examined, which contain the current Fib object, but no root-elements, which do not contain the current Fib object. When the external object comes from the database, the $Identifier$ is negative, otherwise it is positive. While searching for the external objects (with the $Identifier$) in the root-elements, first the root subelements of the next root-element $root_1$ will be searched, in which the Fib object occurs, which requires the external object. In it ($root_1$) only subroot-elements will be checked, which stands after the root subelement, which contains the external object element. So first the $Identifier$ in the next root-element $root_1$ from the external object element are investigated, and than the $Identifier$ after the root-element $root_1$ in the root-element, in which the investigated root-element $root_1$ stands. The section 9.14.4 on page defines the order for the root-elements which determines, how they will searched through, when looking for a $Identifier$. You can also find their, which and in what order the root-elements will be checked while searching for an $Identifier$.
• $( V_1 , \ldots , V_n )$: The vector with the input values, which are needed for the used Fib object.
• $V_i$: The are the input values, which are needed for the used Fib object. The input value $V_i$ is for the i'th input variable of the corresponding root-element or the i'th input variable of the root-element will be set to the value $V_i$ .
• $Obj_o$: The subobjects, that are needed for the extern object. All subobjects are resolved before the current object. The subobjects are ordinary objects, which themselves can contain external objects. All in the subobjects contained external objects are resolved in relation to the current object. Resolved here means, that they are loaded and integrated into the Fib object (contained variables are assigned to existing variables), without evaluating them at this point. The subobjects must be provided in the root-element with the corresponding identifier $Identify$. In the corresponding root-element, the same number of output variable lists with the same number of output variables should be present. (see the root-element 9.14 on page )
• $OutVar_{g_o}$: The output variables, which are provided for the extern object $Obj_o$ from the current Fib object. If an output variable is not yet provided, it is set to $0$.

The number and sequence of the subobjects, input and output variables must match the definition of the external object (the root-element with the $Identifier$).

Notes: The external object ($obj$) element is after the root-element one of the most complicated Fib elements. But reusing subobjects or functions should be worth that effort.

Examples:

• $obj( -3 , x, y )$: The root database object with the identifier $-3$ is used here. The variable $x$ and $y$ are the input parameters (e. g. they can determine the upper left corner wher the inserted object should be display).
• $obj( 5 , x_1, y_1 , ( x_2, y_2, r, pr( (r, 0, 0)_{colorRGB}, p((x_2;y_2)) ) ) )$: The root object with the identifier $5$ is used here. This object, can use the object
  $pr( (r, 0, 0)_{colorRGB}, p((x_2;y_2))$, where the red fraction and the position of the point is determined by the output parameters / varaibles $r$, $x_2$ and $y_2$.