a(+Boolean)

If true (default), use a for the predicate rdf:type. Otherwise use the full resource.

align_prefixes(+Boolean)

Nicely align the @prefix declarations

base(+Base)

Save relative to the given Base

canonize_numbers(+Boolean)

If true (default false), emit numeric datatypes using Prolog's write to achieve canonical output.

comment(+Boolean)

It true (default), write some informative comments between the output segments

encoding(+Encoding)

Encoding used for the output stream. Default is UTF-8.

expand(:Goal)

Query an alternative graph-representation. See below.

indent(+Column)

Indentation for ; -lists. `0' does not indent, but writes on the same line. Default is 8.

graph(+Graph)

Save only the named graph

group(+Boolean)

If true (default), using P-O and O-grouping.

inline_bnodes(+Boolean)

if true (default), inline bnodes that are used once.

abbreviate_literals(+Boolean)

if true (default), omit the type if allowed by turtle.

only_known_prefixes(+Boolean)

Only use prefix notation for known prefixes. Without, some documents produce huge amounts of prefixes.

prefixes(+List)

If provided, uses exactly these prefixes. List is a list of prefix specifications, where each specification is either a term Prefix_-_URI or a prefix that is known to rdf_current_prefix/2.

silent(+Boolean)

If true (default false), do not print the final informational message.

single_line_bnodes(+Bool)

If true (default false), write [...] and (...) on a single line.

subject_white_lines(+Count)

Extra white lines to insert between statements about a different subject. Default is 1.

tab_distance(+Tab)

Distance between tab-stops. `0' forces the library to use only spaces for layout. Default is 8.

user_prefixes(+Boolean)

If true (default), use prefixes from rdf_current_prefix/2.

The option expand allows for serializing alternative graph representations. It is called through call/5, where the first argument is the expand-option, followed by S,P,O,G. G is the graph-option (which is by default a variable). This notably allows for writing RDF graphs represented as rdf(S,P,O) using the following code fragment:

triple_in(RDF, S,P,O,_G) :-
    member(rdf(S,P,O), RDF).

    ...,
    rdf_save_turtle(Out, [ expand(triple_in(RDF)) ]),