Quintus Prolog Manual

c-4: Interface to External Editors

While using the Quintus User Interface you can also interact with an external editor. You might choose to do this if you are more comfortable or familiar with another editor which QUI supports. Currently QUI only provides an interface to the GNU Emacs editor, in addition to the default QUI editor.

c-4-1: Interface to GNU Emacs

In order to set up GNU Emacs as the editor for QUI, you need to set the shell environment variable QUINTUS_EDITOR_PATH to the path of the GNU Emacs executable. You may also need to set the following shell variables:

QUINTUS_LISP_PATH:

When QUI invokes the GNU Emacs editor, it instructs GNU Emacs to load initial lisp files from <quintus installation directory>/editor3.3/gnu/.

DISPLAY:

If the DISPLAY variable is set GNU Emacs will try to create a window on the appropriate display, otherwise it will run in the window that invoked QUI.

c-4-1-1: Invoking GNU Emacs to Edit Files From QUI

There are two ways to invoke GNU Emacs from QUI. The first way is by selecting the Edit... item of the File pulldown menu in the QUI window. The second way is by selecting the Edit Source item of the File pulldown menu in the debugger window. In order to use this second method of invoking GNU Emacs, you must already have a file loaded in your Prolog program under QUI and it must be displayed in the debugger source window. Selecting this menu item will invoke GNU Emacs and place the cursor at the position of the file which defines the predicate you are currently debugging. If you have invoked GNU Emacs from the QUI window, a scratch buffer "*qui-emacs*" is displayed on start up. This scratch buffer is needed to set up the communication channels with QUI. Although the buffer is in "qui" mode, (which is the minor mode in which all files with the extension ".pl" are placed) you cannot use it as a normal prolog buffer as this buffer is not associated with any file. Note that the "*qui-emacs*" buffer is displayed only if you invoke the editor from the QUI main window. If you invoke the editor from the debugger, the file which defines the predicate you are debugging is displayed, not the *qui-emacs*" buffer which is hidden.

c-4-1-2: Key Bindings in "qui" mode

The key bindings are exactly the same as in the Prolog/Emacs interface. You can compile regions, procedures and buffers; you can search for definitions of predicates (find definition) and you can move around clauses.

To use find-definition in QUI, ensure that a gnuemacs process is running, move the cursor into that window, and proceed as in a straight emacs interface (see {manual(d-2-2)}). It cannot be done directly from the QUI main window, so most likely it will be necessary to type in the procedure name and arity rather than select it.

The only thing which is different is that there are no bindings to repeat previous queries to prolog as the QUI window serves that purpose. For a detailed description of the key bindings see {manual(d-2-2)}.

contact: product support sales information