graphical-read-eval-print-loop

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 are 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). This evaluation eventspace is created using (make-eventspace) with a new custodian, so that the eventspace and its threads can be shut down if the user closes the graphical-read-eval-print-loop window. The following parameters are initialized in the evaluation eventspace's handler thread:

• current-output-port -- writes to the frame
• current-error-port -- writes to the frame
• current-input-port -- always returns eof
• current-will-executor -- a new will executor

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) -> void