SWI-Prolog supports quasi-quotations, which allow you to incorporate different languages as part of your Prolog code. Sweep recognizes quasi-quotations and highlights their contents according to the Emacs mode corresponding to the quoted language.
Alist of (type . mode) pairs, where type is a
Prolog quasi-quotation type, and mode is a symbol specifying the
major mode to use for highlighting quasi-quoted text of type
type.
The user option sweeprolog-qq-mode-alist specifies the
association between SWI-Prolog quasi-quotation types and Emacs major
modes. By default, Sweep defines associations for HTML and JavaScript
quasi-quotation types. You can change the default choice of mode for
these highlighting languages and add associations for other languages
by customizing sweeprolog-qq-mode-alist.
If a quasi-quotation type does not have a matching mode in
sweeprolog-qq-mode-alist, Sweep highlights the quoted content
with the sweeprolog-qq-content face.
For more information about quasi-quotations in SWI-Prolog, see library(quasi_quotations) in the SWI-Prolog manual.