Sweep Prolog mode can highlight all occurrences of a given Prolog
variable in the clause in which it appears. By default, occurrences
of the variable at point are highlighted automatically whenever you
move the cursor into a variable. To achieve this, Sweep uses the
Emacs minor mode cursor-sensor-mode which allows for running
hooks when the cursor enters or leaves certain text regions
(see Special Properties in the Elisp
manual).
Highlight occurrences of a Prolog variable in the clause at point. With a prefix argument, clear variable highlighting in the clause at point instead.
Whether to use cursor-sensor-mode to highlight occurrences of
the Prolog variable across the current clause. Defaults to t.
To disable automatic variable highlighting based on the variable at
point, customize sweeprolog-enable-cursor-sensor to nil.
To manually highlight occurrences of a variable in the current clause,
use the command M-x sweeprolog-highlight-variable. This
command prompts for variable to highlight, defaulting to the variable
at point, if any. If you call it with a prefix argument (C-u M-x
sweeprolog-highlight-variable RET), it clears all variable
highlighting in the current clause instead.