SWI-Prolog 8.2.4 Reference Manual: Section A.20

A.20 library(listing): List programs and pretty print clauses

To be done: - More settings, support Coding Guidelines for Prolog and make the suggestions there the default.
- Provide persistent user customization

This module implements listing code from the internal representation in a human readable format.

listing/0 lists a module.
listing/1 lists a predicate or matching clause
listing/2 lists a predicate or matching clause with options
portray_clause/2 pretty-prints a clause-term

Layout can be customized using library(settings). The effective settings can be listed using