Modes are the heart of (Pce)Emacs. Modes define dedicated editing
support for a particular kind of (source) text. For our purpose we want
Prolog mode. There are various ways to make PceEmacs use Prolog
mode for a file.
- Using the proper extension
If the file ends in .pl or the selected alternative (e.g. .pro)
extension, Prolog mode is selected.
- Using
#!/path/to/.../swipl
If the file is a Prolog Script file, starting with the line
#!/path/to/swipl options, Prolog mode is
selected regardless of the extension.
- Using
-*- Prolog -*-
If the above sequence appears in the first line of the file (inside a
Prolog comment) Prolog mode is selected.
- Explicit selection
Finally, using File/Mode/Prolog you can switch to
Prolog mode explicitly.
