encoding issues with Prolog API

[guregu]

Atom quoting

SWI doesn't quote non-ASCII by default, but ichiban/prolog requires it. So Japanese, for example '漢字' will break it.

There's a workaround:

pengines:write_result(prolog, Event, _) :-
    format('Content-type: text/x-prolog; charset=UTF-8~n~n'),
    write_term(Event,
               [ quoted(true),
                 quote_non_ascii(true),           % 🆕
                 character_escapes_unicode(true), % 🆕
                 ignore_ops(true),
                 fullstop(true),
                 blobs(portray),
                 portray_goal(portray_blob),
                 nl(true)
               ]).

Operator quoting

Our Write params in predicate.go aren't good enough. We need to pass at LEAST the comma operator to engine.Write to avoid sending invalid code like , (foo, bar) which SWI doesn't like. Either fix it to be ','(foo, bar) or (foo, bar).

[guregu]

Fixed the operator issue in v0.1.2 and added a note about atom quoting in the README.