module Rdf_graph:sig
..end
The graph provides an abstraction of the storage used (memory, database, ...). The graph is modified in place.
Example of usage:
let options =
[
"storage", "mysql" ;
"database", "mydb";
"user", "john" ;
]
in
let graph = Rdf_graph.open_graph ~options (Rdf_uri.uri "http://hello.fr") in
graph.add_triple
~sub: (Rdf_node.node_of_uri_string "http://john.net")
~pred: (Rdf_node.node_of_uri_string "http://relations.org/hasMailbox")
~obj: (Rdf_node.node_of_literal_string "john@john.net");
...
typeoptions =
(string * string) list
val get_option : ?def:string -> string -> options -> string
get_options name options
returns the value associated to the
option with the given name, in option list.
If the option name is not found in the list, the function raises
the Failure
exception with a message about the missing option.def
: can be used to specify a default value; in this case, if
the option name was not found in list, the default value is
returned instead of raising Failure
.
This is useful only to create your own storage.
module type Storage =sig
..end
exception Storage_error of string * string * exn
Rdf_graph.Make
on a storage.
Each call to a Rdf_graph.Storage
function is embedded so that the
Rdf_graph.Storage_error
exception is raised when an error occurs in
a storage function.
The exception provides the name of the storage, the error message
(obtained with Rdf_graph.Storage.string_of_error
) and the original exception.
Refer to the documentation of Rdf_graph.Storage
for information about
the functions provided by the resulting module.
module type Graph =sig
..end
module Make:
val add_storage : (module Rdf_graph.Storage) -> unit
type
graph = {
|
name : |
|
add_triple : |
|
rem_triple : |
|
add_triple_t : |
|
rem_triple_t : |
|
subjects_of : |
|
predicates_of : |
|
objects_of : |
|
find : |
|
exists : |
|
exists_t : |
|
subjects : |
|
predicates : |
|
objects : |
|
transaction_start : |
|
transaction_commit : |
|
transaction_rollback : |
|
new_blank_id : |
|
namespaces : |
Rdf_graph.open_graph
. It contains
the same functions as in Rdf_graph.Graph
, except the graph data is hidden,
like in a class interface.
Refer to the documentation of Rdf_graph.Storage
for information about
the functions in the fields.val open_graph : ?options:(string * string) list -> Rdf_uri.uri -> graph
open_graph ~options uri_name
creates a new graph. The storage used
is specified by the "storage" option. For example, having ("storage", "mysql")
in the options indicates to use the storage "mysql".
If the specified storage is not registered, the function raises Failure
.
Other options may be used by each storage.
To make sure the storage you want to use is registered, beware of linking the
corresponding module in your executable, either by using the -linkall
option
or by adding a reference to the module in your code.
val merge : graph -> graph -> unit
merge g1 g2
add triples from g2
to g1
.