Frames

Frames within Frames

As we said, a slot can contain another frame. For instance:

v := {
   otherFrame: {
      x: "13",
      y: "20",
   },
   z: 5,
};
In this example, v has two slots, otherFrame and z. otherFrame is also a frame with two slots of its own, x and y.

A frame can also be referred to by more than one frame:

sf:= {
   longitude: 37.48, 
   latitude: 122.24,
};
la:= {
   longitude: 34.4, 
   latitude: 118.15
};
earthquakes:= {
   realRecent: la,
   recent: sf, 
};
laSpec:= {
   city: "Los Angeles", 
   location: la
};

Here you have two frames, sf and la, which are elements of another frame, earthquakes. la is simultaneously the value of a slot in laSpec as well. FIGURE 3.1 displays a graphic representation of the relationships among these four frames.

FIGURE 3.1 : Frames pointing at other frames.

An online version of Programming for the Newton using Macintosh, 2nd ed. ©1996, 1994, Julie McKeehan and Neil Rhodes.

Last modified: 1 DEC 1996