Triples

Triples — RDF Triples

Synopsis

enum                raptor_term_type;
                    raptor_term;
                    raptor_term_value;
                    raptor_term_blank_value;
                    raptor_term_literal_value;
raptor_term *       raptor_new_term_from_blank          (raptor_world *world,
                                                         const unsigned char *blank);
raptor_term *       raptor_new_term_from_counted_blank  (raptor_world *world,
                                                         const unsigned char *blank,
                                                         size_t length);
raptor_term *       raptor_new_term_from_literal        (raptor_world *world,
                                                         const unsigned char *literal,
                                                         raptor_uri *datatype,
                                                         const unsigned char *language);
raptor_term *       raptor_new_term_from_counted_literal
                                                        (raptor_world *world,
                                                         const unsigned char *literal,
                                                         size_t literal_len,
                                                         raptor_uri *datatype,
                                                         const unsigned char *language,
                                                         unsigned char language_len);
raptor_term *       raptor_new_term_from_counted_uri_string
                                                        (raptor_world *world,
                                                         const unsigned char *uri_string,
                                                         size_t length);
raptor_term *       raptor_new_term_from_uri            (raptor_world *world,
                                                         raptor_uri *uri);
raptor_term *       raptor_new_term_from_uri_string     (raptor_world *world,
                                                         const unsigned char *uri_string);
raptor_term *       raptor_new_term_from_counted_string (raptor_world *world,
                                                         unsigned char *string,
                                                         size_t length);
raptor_term *       raptor_term_copy                    (raptor_term *term);
int                 raptor_term_compare                 (const raptor_term *t1,
                                                         const raptor_term *t2);
int                 raptor_term_equals                  (raptor_term *t1,
                                                         raptor_term *t2);
void                raptor_free_term                    (raptor_term *term);
unsigned char *     raptor_term_to_counted_string       (raptor_term *term,
                                                         size_t *len_p);
unsigned char *     raptor_term_to_string               (raptor_term *term);
int                 raptor_term_ntriples_write          (const raptor_term *term,
                                                         raptor_iostream *iostr);
unsigned char *     raptor_term_to_turtle_counted_string
                                                        (raptor_term *term,
                                                         raptor_namespace_stack *nstack,
                                                         raptor_uri *base_uri,
                                                         size_t *len_p);
unsigned char *     raptor_term_to_turtle_string        (raptor_term *term,
                                                         raptor_namespace_stack *nstack,
                                                         raptor_uri *base_uri);
int                 raptor_term_turtle_write            (raptor_iostream *iostr,
                                                         raptor_term *term,
                                                         raptor_namespace_stack *nstack,
                                                         raptor_uri *base_uri);
                    raptor_statement;
raptor_statement *  raptor_new_statement                (raptor_world *world);
raptor_statement *  raptor_new_statement_from_nodes     (raptor_world *world,
                                                         raptor_term *subject,
                                                         raptor_term *predicate,
                                                         raptor_term *object,
                                                         raptor_term *graph);
void                raptor_free_statement               (raptor_statement *statement);
raptor_statement *  raptor_statement_copy               (raptor_statement *statement);
int                 raptor_statement_compare            (const raptor_statement *s1,
                                                         const raptor_statement *s2);
int                 raptor_statement_equals             (const raptor_statement *s1,
                                                         const raptor_statement *s2);
void                raptor_statement_init               (raptor_statement *statement,
                                                         raptor_world *world);
void                raptor_statement_clear              (raptor_statement *statement);
int                 raptor_statement_print              (const raptor_statement *statement,
                                                         FILE *stream);
int                 raptor_statement_print_as_ntriples  (const raptor_statement *statement,
                                                         FILE *stream);
int                 raptor_statement_ntriples_write     (const raptor_statement *statement,
                                                         raptor_iostream *iostr,
                                                         int write_graph_term);

Description

Representation of RDF statements inside Raptor. They are a 3 or 4-tuple of raptor_term which cover the RDF terms of URI (RAPTOR_TERM_TYPE_URI), Literal (RAPTOR_TERM_TYPE_LITERAL) and Blank Node (RAPTOR_TERM_TYPE_BLANK).

Details

enum raptor_term_type

typedef enum {
  RAPTOR_TERM_TYPE_UNKNOWN = 0,
  RAPTOR_TERM_TYPE_URI     = 1,
  RAPTOR_TERM_TYPE_LITERAL = 2,
  /* unused type 3 */
  RAPTOR_TERM_TYPE_BLANK   = 4
} raptor_term_type;

Type of term in a raptor_statement

Node type 3 is unused but exists to preserve numeric compatibility with librdf_node_type values.

RAPTOR_TERM_TYPE_UNKNOWN

Internal

RAPTOR_TERM_TYPE_URI

RDF URI

RAPTOR_TERM_TYPE_LITERAL

RDF literal

RAPTOR_TERM_TYPE_BLANK

RDF blank node

raptor_term

typedef struct {
  raptor_world* world;

  int usage;

  raptor_term_type type;

  raptor_term_value value;
} raptor_term;

An RDF statement term

raptor_world *world;

world

int usage;

usage reference count (if >0)

raptor_term_type type;

term type

raptor_term_value value;

term values per type

raptor_term_value

typedef union {
  raptor_uri *uri;

  raptor_term_literal_value literal;

  raptor_term_blank_value blank;
} raptor_term_value;

Term value - this typedef exists solely for use in raptor_term

raptor_uri *uri;

uri value when term type is RAPTOR_TERM_TYPE_URI

raptor_term_literal_value literal;

literal value when term type is RAPTOR_TERM_TYPE_LITERAL

raptor_term_blank_value blank;

blank value when term type is RAPTOR_TERM_TYPE_BLANK

raptor_term_blank_value

typedef struct {
  unsigned char *string;
  unsigned int string_len;
} raptor_term_blank_value;

Blank term value - this typedef exists solely for use in raptor_term

unsigned char *string;

literal string

unsigned int string_len;

length of string

raptor_term_literal_value

typedef struct {
  unsigned char *string;
  unsigned int string_len;

  raptor_uri *datatype;

  unsigned char *language;
  unsigned char language_len;
} raptor_term_literal_value;

Literal term value - this typedef exists solely for use in raptor_term

Either datatype or language may be non-NULL but not both.

unsigned char *string;

literal string

unsigned int string_len;

length of string

raptor_uri *datatype;

datatype URI (or NULL)

unsigned char *language;

literal language (or NULL)

unsigned char language_len;

length of language

raptor_new_term_from_blank ()

raptor_term *       raptor_new_term_from_blank          (raptor_world *world,
                                                         const unsigned char *blank);

Constructor - create a new blank node statement term from a UTF-8 encoded blank node ID

Takes a copy of the passed in blank

If blank is NULL or an empty string, creates a new internal identifier and uses it. This will use the handler set with raptor_world_set_generate_bnodeid_parameters()

world :

raptor world

blank :

UTF-8 encoded blank node identifier (or NULL)

Returns :

new term or NULL on failure

raptor_new_term_from_counted_blank ()

raptor_term *       raptor_new_term_from_counted_blank  (raptor_world *world,
                                                         const unsigned char *blank,
                                                         size_t length);

Constructor - create a new blank node statement term from a counted UTF-8 encoded blank node ID

Takes a copy of the passed in blank

If blank is NULL, creates a new internal identifier and uses it. This will use the handler set with raptor_world_set_generate_bnodeid_parameters()

Note: The blank need not be NULL terminated - a NULL will be added to the copied string used.

world :

raptor world

blank :

UTF-8 encoded blank node identifier (or NULL)

length :

length of identifier (or 0)

Returns :

new term or NULL on failure

raptor_new_term_from_literal ()

raptor_term *       raptor_new_term_from_literal        (raptor_world *world,
                                                         const unsigned char *literal,
                                                         raptor_uri *datatype,
                                                         const unsigned char *language);

Constructor - create a new literal statement term

Takes copies of the passed in literal, datatype, language

Only one of language or datatype may be given. If both are given, NULL is returned. If language is the empty string, it is the equivalent to NULL.

world :

raptor world

literal :

UTF-8 encoded literal string (or NULL for empty literal)

datatype :

literal datatype URI (or NULL)

language :

literal language (or NULL)

Returns :

new term or NULL on failure

raptor_new_term_from_counted_literal ()

raptor_term *       raptor_new_term_from_counted_literal
                                                        (raptor_world *world,
                                                         const unsigned char *literal,
                                                         size_t literal_len,
                                                         raptor_uri *datatype,
                                                         const unsigned char *language,
                                                         unsigned char language_len);

Constructor - create a new literal statement term from a counted UTF-8 encoded literal string

Takes copies of the passed in literal, datatype, language

Only one of language or datatype may be given. If both are given, NULL is returned. If language is the empty string, it is the equivalent to NULL.

Note: The literal need not be NULL terminated - a NULL will be added to the copied string used.

world :

raptor world

literal :

UTF-8 encoded literal string (or NULL for empty literal)

literal_len :

length of literal

datatype :

literal datatype URI (or NULL)

language :

literal language (or NULL for no language)

language_len :

literal language length

Returns :

new term or NULL on failure

raptor_new_term_from_counted_uri_string ()

raptor_term *       raptor_new_term_from_counted_uri_string
                                                        (raptor_world *world,
                                                         const unsigned char *uri_string,
                                                         size_t length);

Constructor - create a new URI statement term from a UTF-8 encoded Unicode string

Note: The uri_string need not be NULL terminated - a NULL will be added to the copied string used.

world :

raptor world

uri_string :

UTF-8 encoded URI string.

length :

length of URI string

Returns :

new term or NULL on failure

raptor_new_term_from_uri ()

raptor_term *       raptor_new_term_from_uri            (raptor_world *world,
                                                         raptor_uri *uri);

Constructor - create a new URI statement term

Takes a copy (reference) of the passed in uri

world :

raptor world

uri :

uri

Returns :

new term or NULL on failure

raptor_new_term_from_uri_string ()

raptor_term *       raptor_new_term_from_uri_string     (raptor_world *world,
                                                         const unsigned char *uri_string);

Constructor - create a new URI statement term from a UTF-8 encoded Unicode string

world :

raptor world

uri_string :

UTF-8 encoded URI string.

Returns :

new term or NULL on failure

raptor_new_term_from_counted_string ()

raptor_term *       raptor_new_term_from_counted_string (raptor_world *world,
                                                         unsigned char *string,
                                                         size_t length);

Constructor - create a new term from a Turtle / N-Triples format string in UTF-8

See also raptor_term_to_counted_string() and raptor_term_to_string()

world :

raptor world

string :

N-Triples format string (UTF-8)

length :

length of string (or 0)

Returns :

new term or NULL on failure

raptor_term_copy ()

raptor_term *       raptor_term_copy                    (raptor_term *term);

Copy constructor - get a copy of a statement term

term :

raptor term

Returns :

new term object or NULL on failure

raptor_term_compare ()

int                 raptor_term_compare                 (const raptor_term *t1,
                                                         const raptor_term *t2);

Compare a pair of raptor_term

If types are different, the raptor_term_type order is used.

Resource and datatype URIs are compared with raptor_uri_compare(), blank nodes and literals with strcmp(). If one literal has no language, it is earlier than one with a language. If one literal has no datatype, it is earlier than one with a datatype.

t1 :

first term

t2 :

second term

Returns :

<0 if t1 is before t2, 0 if equal, >0 if t1 is after t2

raptor_term_equals ()

int                 raptor_term_equals                  (raptor_term *t1,
                                                         raptor_term *t2);

Compare a pair of raptor_term for equality

t1 :

first term

t2 :

second term

Returns :

non-0 if the terms are equal

raptor_free_term ()

void                raptor_free_term                    (raptor_term *term);

Destructor - destroy a raptor_term object.

term :

raptor_term object

raptor_term_to_counted_string ()

unsigned char *     raptor_term_to_counted_string       (raptor_term *term,
                                                         size_t *len_p);

Turns a raptor term into a N-Triples format counted string.

Turns the given term into an N-Triples escaped string using all the escapes as defined in http://www.w3.org/TR/rdf-testcases/ntriples

This function uses raptor_term_ntriples_write() to write to an raptor_iostream which is the prefered way to write formatted output.

See also raptor_new_term_from_counted_string() to reverse this.

See also raptor_term_to_turtle_string() to write as Turtle which will include Turtle syntax such as 'true' for booleans and """quoting"""

term :

raptor_term

len_p :

Pointer to location to store length of new string (if not NULL)

Returns :

the new string or NULL on failure. The length of the new string is returned in *len_p if len_p is not NULL.

raptor_term_to_string ()

unsigned char *     raptor_term_to_string               (raptor_term *term);

Turns a raptor term into a N-Triples format string.

Turns the given term into an N-Triples escaped string using all the escapes as defined in http://www.w3.org/TR/rdf-testcases/ntriples

See also raptor_new_term_from_counted_string() to reverse this.

See also raptor_term_to_turtle_string() to write as Turtle which will include Turtle syntax such as 'true' for booleans and """quoting"""

term :

raptor_term

Returns :

the new string or NULL on failure.

raptor_term_ntriples_write ()

int                 raptor_term_ntriples_write          (const raptor_term *term,
                                                         raptor_iostream *iostr);

Write a raptor_term formatted in N-Triples format to a raptor_iostream

Deprecated: Use raptor_term_escaped_write() that allows configuring format detail flags.

term :

term to write

iostr :

raptor iostream

Returns :

non-0 on failure

raptor_term_to_turtle_counted_string ()

unsigned char *     raptor_term_to_turtle_counted_string
                                                        (raptor_term *term,
                                                         raptor_namespace_stack *nstack,
                                                         raptor_uri *base_uri,
                                                         size_t *len_p);

Convert raptor_term to a string. Caller has responsibility to free the string.

Note: This creates and destroys several internal objects for each call so for more efficient writing, create a turtle serializer.

See also raptor_term_to_counted_string() which writes in simpler N-Triples with no Turtle abbreviated forms, and is quicker.

term :

term

nstack :

namespace stack

base_uri :

base URI

len_p :

Pointer to location to store length of new string (if not NULL)

Returns :

the new string or NULL on failure. The length of the new string is returned in *len_p if len_p is not NULL.

raptor_term_to_turtle_string ()

unsigned char *     raptor_term_to_turtle_string        (raptor_term *term,
                                                         raptor_namespace_stack *nstack,
                                                         raptor_uri *base_uri);

Convert raptor_term to a string. Caller has responsibility to free the string.

See also raptor_term_to_counted_string() which writes in simpler N-Triples with no Turtle abbreviated forms, and is quicker.

term :

term

nstack :

namespace stack

base_uri :

base URI

Returns :

the new string or NULL on failure.

raptor_term_turtle_write ()

int                 raptor_term_turtle_write            (raptor_iostream *iostr,
                                                         raptor_term *term,
                                                         raptor_namespace_stack *nstack,
                                                         raptor_uri *base_uri);

Write raptor_term to a stream in turtle syntax (using QNames).

Note: This creates and destroys several internal objects for each call so for more efficient writing, create a turtle serializer.

iostr :

iostream for writing

term :

term

nstack :

namespace stack

base_uri :

base URI

Returns :

non-0 on failure

raptor_statement

typedef struct {
  raptor_world* world;
  int usage;
  raptor_term* subject;
  raptor_term* predicate;
  raptor_term* object;
  raptor_term* graph;
} raptor_statement;

An RDF triple with optional graph name (quad)

See raptor_term for a description of how the fields may be used. As returned by a parser statement_handler.

raptor_world *world;

world pointer

int usage;

usage count

raptor_term *subject;

statement subject

raptor_term *predicate;

statement predicate

raptor_term *object;

statement object

raptor_term *graph;

statement graph name (or NULL if not present)

raptor_new_statement ()

raptor_statement *  raptor_new_statement                (raptor_world *world);

Constructor - create a new raptor_statement.

world :

raptor world

Returns :

new raptor statement or NULL on failure

raptor_new_statement_from_nodes ()

raptor_statement *  raptor_new_statement_from_nodes     (raptor_world *world,
                                                         raptor_term *subject,
                                                         raptor_term *predicate,
                                                         raptor_term *object,
                                                         raptor_term *graph);

Constructor - create a new raptor_statement from a set of terms

The subject, predicate, object and graph become owned by the statement.

world :

raptor world

subject :

subject term (or NULL)

predicate :

predicate term (or NULL)

object :

object term (or NULL)

graph :

graph name term (or NULL)

Returns :

new raptor statement or NULL on failure

raptor_free_statement ()

void                raptor_free_statement               (raptor_statement *statement);

Destructor

statement :

statement

raptor_statement_copy ()

raptor_statement *  raptor_statement_copy               (raptor_statement *statement);

Copy a raptor_statement.

statement :

statement to copy

Returns :

a new raptor_statement or NULL on error

raptor_statement_compare ()

int                 raptor_statement_compare            (const raptor_statement *s1,
                                                         const raptor_statement *s2);

Compare a pair of raptor_statement

Uses raptor_term_compare() to check ordering between subjects, predicates and objects of statements.

s1 :

first statement

s2 :

second statement

Returns :

<0 if s1 is before s2, 0 if equal, >0 if s1 is after s2

raptor_statement_equals ()

int                 raptor_statement_equals             (const raptor_statement *s1,
                                                         const raptor_statement *s2);

Compare a pair of raptor_statement for equality

s1 :

first statement

s2 :

second statement

Returns :

non-0 if statements are equal

raptor_statement_init ()

void                raptor_statement_init               (raptor_statement *statement,
                                                         raptor_world *world);

Initialize a static raptor_statement.

statement :

statement to initialize

world :

raptor world

raptor_statement_clear ()

void                raptor_statement_clear              (raptor_statement *statement);

Empty a raptor_statement of terms.

statement :

raptor_statement object

raptor_statement_print ()

int                 raptor_statement_print              (const raptor_statement *statement,
                                                         FILE *stream);

Print a raptor_statement to a stream.

statement :

raptor_statement object to print

stream :

FILE* stream

Returns :

non-0 on failure

raptor_statement_print_as_ntriples ()

int                 raptor_statement_print_as_ntriples  (const raptor_statement *statement,
                                                         FILE *stream);

Print a raptor_statement in N-Triples form.

statement :

raptor_statement to print

stream :

FILE* stream

Returns :

non-0 on failure

raptor_statement_ntriples_write ()

int                 raptor_statement_ntriples_write     (const raptor_statement *statement,
                                                         raptor_iostream *iostr,
                                                         int write_graph_term);

Write a raptor_statement formatted in N-Triples or N-Quads format to a raptor_iostream

statement :

statement to write

iostr :

raptor iostream

write_graph_term :

flag to write graph term if present

Returns :

non-0 on failure


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