statement

statement

Functions

Types and Values

Description

Functions

librdf_new_statement ()

librdf_statement *
librdf_new_statement (librdf_world *world);

Constructor - create a new empty librdf_statement.

Parameters

world

redland world object

 

Returns

a new librdf_statement or NULL on failure


librdf_new_statement_from_statement ()

librdf_statement *
librdf_new_statement_from_statement (librdf_statement *statement);

Copy constructor - create a new librdf_statement from an existing librdf_statement. Creates a deep copy - changes to original statement nodes are not reflected in the copy.

Parameters

statement

librdf_statement to copy

 

Returns

a new librdf_statement with copy or NULL on failure


librdf_new_statement_from_statement2 ()

librdf_statement *
librdf_new_statement_from_statement2 (librdf_statement *statement);

Copy constructor - create a new librdf_statement from an existing librdf_statement. Creates a shallow copy - changes to original statement nodes are reflected in the copy.

Parameters

statement

librdf_statement to copy

 

Returns

a new librdf_statement with copy or NULL on failure


librdf_new_statement_from_nodes ()

librdf_statement *
librdf_new_statement_from_nodes (librdf_world *world,
                                 librdf_node *subject,
                                 librdf_node *predicate,
                                 librdf_node *object);

Constructor - create a new librdf_statement from existing librdf_node objects.

The node objects become owned by the new statement (or freed on error).

Parameters

world

redland world object

 

subject

librdf_node

 

predicate

librdf_node

 

object

librdf_node

 

Returns

a new librdf_statement with copy or NULL on failure


librdf_statement_init ()

void
librdf_statement_init (librdf_world *world,
                       librdf_statement *statement);

Initialise a statically declared librdf_statement.

This MUST be called on a statically declared librdf_statement to initialise it properly. It is the responsibility of the user of the statically allocated librdf_statement to deal with deallocation of any statement parts (subject, predicate, object).

Parameters

world

redland world object

 

statement

librdf_statement object

 

librdf_statement_clear ()

void
librdf_statement_clear (librdf_statement *statement);

Empty a librdf_statement of nodes.

Parameters

statement

librdf_statement object

 

librdf_free_statement ()

void
librdf_free_statement (librdf_statement *statement);

Destructor - destroy a librdf_statement.

Parameters

statement

librdf_statement object

 

librdf_statement_get_subject ()

librdf_node *
librdf_statement_get_subject (librdf_statement *statement);

Get the statement subject.

This method returns a SHARED pointer to the subject which must be copied by the caller if needed.

Parameters

statement

librdf_statement object

 

Returns

a pointer to the librdf_node of the statement subject -


librdf_statement_set_subject ()

void
librdf_statement_set_subject (librdf_statement *statement,
                              librdf_node *node);

Set the statement subject.

The subject passed in becomes owned by the statement object and must not be used by the caller after this call.

Parameters

statement

librdf_statement object

 

node

librdf_node of subject

 

librdf_statement_get_predicate ()

librdf_node *
librdf_statement_get_predicate (librdf_statement *statement);

Get the statement predicate.

This method returns a SHARED pointer to the predicate which must be copied by the caller if needed.

Parameters

statement

librdf_statement object

 

Returns

a pointer to the librdf_node of the statement predicate -


librdf_statement_set_predicate ()

void
librdf_statement_set_predicate (librdf_statement *statement,
                                librdf_node *node);

Set the statement predicate.

The predicate passed in becomes owned by the statement object and must not be used by the caller after this call.

Parameters

statement

librdf_statement object

 

node

librdf_node of predicate

 

librdf_statement_get_object ()

librdf_node *
librdf_statement_get_object (librdf_statement *statement);

Get the statement object.

This method returns a SHARED pointer to the object which must be copied by the caller if needed.

Parameters

statement

librdf_statement object

 

Returns

a pointer to the librdf_node of the statement object -


librdf_statement_set_object ()

void
librdf_statement_set_object (librdf_statement *statement,
                             librdf_node *node);

Set the statement object.

The object passed in becomes owned by the statement object and must not be used by the caller after this call.

Parameters

statement

librdf_statement object

 

node

librdf_node of object

 

librdf_statement_is_complete ()

int
librdf_statement_is_complete (librdf_statement *statement);

Check if statement is a complete and legal RDF triple.

Checks that all subject, predicate, object fields are present and they have the allowed node types.

Parameters

statement

librdf_statement object

 

Returns

non 0 if the statement is complete and legal


librdf_statement_to_string ()

unsigned char *
librdf_statement_to_string (librdf_statement *statement);

librdf_statement_to_string is deprecated and should not be used in newly-written code.

Format the librdf_statement as a string.

Formats the statement as a newly allocate string that must be freed by the caller.

Deprecated : Use librdf_statement_write() to write to raptor_iostream which can be made to write to a string. Use a librdf_serializer to write proper syntax formats.

Parameters

statement

the statement

 

Returns

the string or NULL on failure.


librdf_statement_print ()

void
librdf_statement_print (librdf_statement *statement,
                        FILE *fh);

Pretty print the statement to a file descriptor.

This method is for debugging and the format of the output should not be relied on.

Parameters

statement

the statement

 

fh

file handle

 

librdf_statement_equals ()

int
librdf_statement_equals (librdf_statement *statement1,
                         librdf_statement *statement2);

Check if two statements are equal.

Parameters

statement1

first librdf_statement

 

statement2

second librdf_statement

 

Returns

non 0 if statements are equal


librdf_statement_match ()

int
librdf_statement_match (librdf_statement *statement,
                        librdf_statement *partial_statement);

Match a statement against a 'partial' statement.

A partial statement is where some parts of the statement - subject, predicate or object can be empty (NULL). Empty parts match against any value, parts with values must match exactly. Node matching is done via librdf_node_equals()

Parameters

statement

statement

 

partial_statement

statement with possible empty parts

 

Returns

non 0 on match


librdf_statement_encode ()

size_t
librdf_statement_encode (librdf_statement *statement,
                         unsigned char *buffer,
                         size_t length);

librdf_statement_encode is deprecated and should not be used in newly-written code.

Serialise a statement into a buffer.

Encodes the given statement in the buffer, which must be of sufficient size. If buffer is NULL, no work is done but the size of buffer required is returned.

Deprecated : Use librdf_statement_encode2()

Parameters

statement

the statement to serialise

 

buffer

the buffer to use

 

length

buffer size

 

Returns

the number of bytes written or 0 on failure.


librdf_statement_encode2 ()

size_t
librdf_statement_encode2 (librdf_world *world,
                          librdf_statement *statement,
                          unsigned char *buffer,
                          size_t length);

Serialise a statement into a buffer.

Encodes the given statement in the buffer, which must be of sufficient size. If buffer is NULL, no work is done but the size of buffer required is returned.

Parameters

world

redland world

 

statement

the statement to serialise

 

buffer

the buffer to use

 

length

buffer size

 

Returns

the number of bytes written or 0 on failure.


librdf_statement_encode_parts ()

size_t
librdf_statement_encode_parts (librdf_statement *statement,
                               librdf_node *context_node,
                               unsigned char *buffer,
                               size_t length,
                               librdf_statement_part fields);

librdf_statement_encode_parts is deprecated and should not be used in newly-written code.

Serialise parts of a statement into a buffer.

Encodes the given statement in the buffer, which must be of sufficient size. If buffer is NULL, no work is done but the size of buffer required is returned.

The fields values are or-ed combinations of: LIBRDF_STATEMENT_SUBJECT LIBRDF_STATEMENT_PREDICATE LIBRDF_STATEMENT_OBJECT or LIBRDF_STATEMENT_ALL for subject,prdicate,object fields

If context_node is given, it is encoded also

Deprecated : This will no longer be a public API

Parameters

statement

statement to serialise

 

context_node

librdf_node context node (can be NULL)

 

buffer

the buffer to use

 

length

buffer size

 

fields

fields to encode

 

Returns

the number of bytes written or 0 on failure.


librdf_statement_encode_parts2 ()

size_t
librdf_statement_encode_parts2 (librdf_world *world,
                                librdf_statement *statement,
                                librdf_node *context_node,
                                unsigned char *buffer,
                                size_t length,
                                librdf_statement_part fields);

Serialise parts of a statement into a buffer.

Encodes the given statement in the buffer, which must be of sufficient size. If buffer is NULL, no work is done but the size of buffer required is returned.

The fields values are or-ed combinations of: LIBRDF_STATEMENT_SUBJECT LIBRDF_STATEMENT_PREDICATE LIBRDF_STATEMENT_OBJECT or LIBRDF_STATEMENT_ALL for subject,prdicate,object fields

If context_node is given, it is encoded also

Parameters

world

redland world object

 

statement

statement to serialise

 

context_node

librdf_node context node (can be NULL)

 

buffer

the buffer to use

 

length

buffer size

 

fields

fields to encode

 

Returns

the number of bytes written or 0 on failure.


librdf_statement_decode ()

size_t
librdf_statement_decode (librdf_statement *statement,
                         unsigned char *buffer,
                         size_t length);

librdf_statement_decode is deprecated and should not be used in newly-written code.

Decodes a statement from a buffer. (ALWAYS FAILS)

Used to decode the serialised statement as created by librdf_statement_encode() from the given buffer.

Deprecated : Replaced by librdf_statement_decode2() which works.

Parameters

statement

the statement to deserialise into

 

buffer

the buffer to use

 

length

buffer size

 

Returns

0 signifying failure


librdf_statement_decode2 ()

size_t
librdf_statement_decode2 (librdf_world *world,
                          librdf_statement *statement,
                          librdf_node **context_node,
                          unsigned char *buffer,
                          size_t length);

Decodes a statement + context node from a buffer.

Decodes the serialised statement (as created by librdf_statement_encode() ) from the given buffer. If a context node is found and context_node is not NULL, a pointer to the new librdf_node is stored in *context_node.

Parameters

world

redland world

 

statement

the statement to deserialise into

 

context_node

pointer to librdf_node context_node to deserialise into

 

buffer

the buffer to use

 

length

buffer size

 

Returns

number of bytes used or 0 on failure (bad encoding, allocation failure)


librdf_statement_decode_parts ()

size_t
librdf_statement_decode_parts (librdf_statement *statement,
                               librdf_node **context_node,
                               unsigned char *buffer,
                               size_t length);

librdf_statement_decode_parts is deprecated and should not be used in newly-written code.

Decodes a statement + context node from a buffer. (ALWAYS FAILS)

Used to decode the serialised statement as created by librdf_statement_encode() from the given buffer.

Deprecated : Replaced by librdf_statement_decode2() which works.

Parameters

statement

the statement to deserialise into

 

context_node

pointer to librdf_node context_node to deserialise into

 

buffer

the buffer to use

 

length

buffer size

 

Returns

0 signifying failure


librdf_statement_write ()

int
librdf_statement_write (librdf_statement *statement,
                        raptor_iostream *iostr);

Write the statement to an iostream

This method is for debugging and the format of the output should not be relied on.

Parameters

statement

the statement

 

iostr

raptor iostream to write to

 

Returns

non-0 on failure

Types and Values

librdf_statement

typedef raptor_statement librdf_statement;

Redland statement class.


enum librdf_statement_part

Flags that are or-ed to indicate statement parts.

Used in fields arguments to methods such as the public librdf_statement_encode_parts() librdf_statement_decode_parts() librdf_new_stream_from_node_iterator().

Members

LIBRDF_STATEMENT_SUBJECT

Subject of a statement.

 

LIBRDF_STATEMENT_PREDICATE

Predicate of a statement.

 

LIBRDF_STATEMENT_OBJECT

Object of a statement.

 

LIBRDF_STATEMENT_ALL

All parts of a statement.