prolog-electric--colon

prolog-electric--colon is a compiled Lisp function in `prolog.el'.

(prolog-electric--colon)

If `prolog-electric-colon-flag' is non-nil, insert the electric `:' construct.
That is, insert space (if appropriate), `:-' and newline if colon is pressed
at the end of a line that starts in the first column (i.e., clause heads).