Chapter 5  Embedding into Tcl/Tk

This chapter describes how to embed ECLⁱPS^e into a Tcl host program. Tcl/Tk is a cross-platform toolkit for the development of graphical user interfaces. The facilities described here make it possible to implement ECLⁱPS^e applications with platform-independent graphical user interfaces. The interface is similar in spirit to the ECLⁱPS^e embedding interfaces for other languages.

An alternative method of using ECLⁱPS^e with Tcl is to use the Tcl remote interface, described in chapter 6. In this case, the ECLⁱPS^e is ran as a separate program. The facilities provided by the remote and embedding interfaces are largely compatible, so that it is possible to reuse the same Tcl and ECLⁱPS^e code in both interface. The advantage of the embedding interface is that ECLⁱPS^e is much more tightly coupled with the Tcl program, and communication between the two is more efficient. The advantage of the remote interface is that the Tcl and ECLⁱPS^e programs are not tightly coupled, and in fact can be run on separate machines.

The tkeclipse development environment is entirely implemented using the facilities described in this chapter. The toplevel of tkeclipse is currently implemented using only the embedding interface, but the development tools can be used with both the embedding and remote interfaces.

• Loading the interface
• Initialising the ECLⁱPS^e Subsystem
• Shutting down the ECLⁱPS^e Subsystem
• Passing Goals and Control to ECLⁱPS^e
• Communication via Queues
  • From-ECLⁱPS^e to Tcl
  • To-ECLⁱPS^e from Tcl
• Attaching Handlers to Queues
  • Tcl handlers
  • ECLⁱPS^e handlers
• Obtaining the Interface Type
• Type conversion between Tcl and ECLⁱPS^e
• Incompatible and obsolete commands