This is actually very common.
Search for the predicates that make use of DCGS, e.g.
- phrase/2
- phrase/3
- phrase_from_file/2
- phrase_from_file/3
- phrase_from_stream/2
- phrase_from_quasi_quotation/2
One of the better places to search for such code is on GitHub but even using GitHub search for this is tedious.
Over the years I have found that downloading quality GitHub repositories such as these and searching them with find in files
options of editors like NotePad++ is often much more effective.