graphical-read-eval-print-loop in Miscellaneous

Similar to MzScheme's read-eval-print-loop, except that none of read-eval-print-loop's configuration parameters are used (such as current-read) and the interaction occurs in a GUI window instead of using the current input and output ports.

Expressions entered into the graphical read-eval-print loop can be evaluated in an eventspace (and thread) that is distinct from the one implementing the graphical-read-eval-print-loop window (i.e., the current eventspace when graphical-read-eval-print-loop is called).

If no eventspace is provided, or if #f is provided, an evaluation eventspace is created using (make-eventspace) with a new custodian; the eventspace and its threads are be shut down when the user closes the graphical-read-eval-print-loop window. If an eventspace is provided, closing the window performs no shut-down actions on eventspace.

When redirect-ports? is true, the following parameters are initialized in the created eventspace's handler thread:

• current-output-port -- writes to the frame

• current-error-port -- writes to the frame

• current-input-port -- always returns eof

See (see parameters, section 7.7 in PLT MzScheme: Language Manual) for more information about these parameters.

The keymap for the read-eval-print loop's editor is initialized by calling the current keymap initializer procedure, which is determined by the current-text-keymap-initializer parameter.

• (graphical-read-eval-print-loop eval-eventspace redirect-ports?) -> void
     eval-eventspace = #f : eventspace
     redirect-ports? = (not eval-eventspace) : boolean