Question

I was wondering what this code does:

:- set_prolog_flag(toplevel_print_options,
  [quoted(true), portray(true), attributes(portray), max_depth(100)]).

I have seen it in some of the sample codes my prof has posted on his website but I have no clue what it does. Thanks for your help in advance.

Answer 1

I believe it might have something to do with making program output more formatted (and thus, more readable or accessible.)

See this article: “Help… Prolog writes [x, y, z|…], I want the whole answer”.

Basically, in the case of your code’s settings… it looks like the code is just setting some formatting for output. The max_depth setting means that anything that is nested more than (100, in your case,) levels will then be written as .... The rest of the options just enable normal output.