Options provides additional processing options. Defined options are:

blank_nodes(+ShareMode)

How to handle equivalent blank nodes. If share (default), equivalent blank nodes are shared in the same resource.

base_uri(+URI)

URI that is used for rdf:about="" and other RDF constructs that are relative to the base uri. Default is the source URL.

concurrent(+Jobs)

If FileOrList is a list of files, process the input files using Jobs threads concurrently. Default is the mininum of the number of cores and the number of inputs. Higher values can be useful when loading inputs from (slow) network connections. Using 1 (one) does not use separate worker threads.

format(+Format)

Specify the source format explicitly. Normally this is deduced from the filename extension or the mime-type. The core library understands the formats xml (RDF/XML) and triples (internal quick load and cache format). Plugins, such as library(semweb/turtle) extend the set of recognised extensions.

graph(?Graph)

Named graph in which to load the data. It is not allowed to load two sources into the same named graph. If Graph is unbound, it is unified to the graph into which the data is loaded. The default graph is a file:// URL when loading a file or, if the specification is a URL, its normalized version without the optional #fragment.

if(Condition)

When to load the file. One of true, changed (default) or not_loaded.

modified(-Modified)

Unify Modified with one of not_modified, cached(File), last_modified(Stamp) or unknown.

cache(Bool)

If false, do not use or create a cache file.

register_namespaces(Bool)

If true (default false), register xmlns namespace declarations or Turtle @prefix prefixes using rdf_register_prefix/3 if there is no conflict.

silent(+Bool)

If true, the message reporting completion is printed using level silent. Otherwise the level is informational. See also print_message/2.

prefixes(-Prefixes)

Returns the prefixes defined in the source data file as a list of pairs.

multifile +Boolean

Indicate that the addressed graph may be populated with triples from multiple sources. This disables caching and avoids that an rdf_load/2 call affecting the specified graph cleans the graph.

Other options are forwarded to process_rdf/3. By default, rdf_load/2 only loads RDF/XML from files. It can be extended to load data from other formats and locations using plugins. The full set of plugins relevant to support different formats and locations is below:

:- use_module(library(semweb/turtle)).        % Turtle and TriG
:- use_module(library(semweb/rdf_ntriples)).
:- use_module(library(semweb/rdf_zlib_plugin)).
:- use_module(library(semweb/rdf_http_plugin)).
:- use_module(library(http/http_ssl_plugin)).

See also

- rdf_open_hook/3, library(semweb/rdf_persistency) and library(semweb/rdf_cache)