]> Literal 3 RASQAL Library Literal RDF literals and RDF query-specific literals. typedef rasqal_literal; enum rasqal_literal_type; rasqal_literal* rasqal_new_typed_literal (rasqal_world *world, rasqal_literal_type type, unsigned char *string); rasqal_literal* rasqal_new_boolean_literal (rasqal_world *world, int value); rasqal_literal* rasqal_new_decimal_literal (rasqal_world *world, unsigned char *string); rasqal_literal* rasqal_new_decimal_literal_from_decimal (rasqal_world *world, unsigned char *string, rasqal_xsd_decimal *decimal); rasqal_literal* rasqal_new_double_literal (rasqal_world *world, double d); rasqal_literal* rasqal_new_float_literal (rasqal_world *world, float f); rasqal_literal* rasqal_new_integer_literal (rasqal_world *world, rasqal_literal_type type, int integer); rasqal_literal* rasqal_new_pattern_literal (rasqal_world *world, unsigned char *pattern, const char *flags); rasqal_literal* rasqal_new_simple_literal (rasqal_world *world, rasqal_literal_type type, unsigned char *string); rasqal_literal* rasqal_new_string_literal (rasqal_world *world, unsigned char *string, const char *language, raptor_uri *datatype, unsigned char *datatype_qname); rasqal_literal* rasqal_new_uri_literal (rasqal_world *world, raptor_uri *uri); rasqal_literal* rasqal_new_variable_literal (rasqal_world *world, rasqal_variable *variable); rasqal_literal* rasqal_new_literal_from_literal (rasqal_literal *l); void rasqal_free_literal (rasqal_literal *l); rasqal_literal* rasqal_literal_as_node (rasqal_literal *l); const unsigned char* rasqal_literal_as_string (rasqal_literal *l); const unsigned char* rasqal_literal_as_string_flags (rasqal_literal *l, int flags, int *error); rasqal_variable* rasqal_literal_as_variable (rasqal_literal *l); int rasqal_literal_compare (rasqal_literal *l1, rasqal_literal *l2, int flags, int *error); raptor_uri* rasqal_literal_datatype (rasqal_literal *l); int rasqal_literal_equals (rasqal_literal *l1, rasqal_literal *l2); void rasqal_literal_print (rasqal_literal *l, FILE *fh); void rasqal_literal_print_type (rasqal_literal *l, FILE *fh); rasqal_literal* rasqal_literal_value (rasqal_literal *l); A class for handling RDF terms (URI, blank nodes, strings, datatyped literals) as well as those natively used in a query such as boolean, double, floating, integer, regex pattern and variables. rasqal_literaltypedef struct rasqal_literal_s rasqal_literal; Rasqal literal class. rasqal_literal_typetypedef enum { /* internal */ RASQAL_LITERAL_UNKNOWN, RASQAL_LITERAL_BLANK, RASQAL_LITERAL_URI, RASQAL_LITERAL_STRING, RASQAL_LITERAL_BOOLEAN, RASQAL_LITERAL_INTEGER, RASQAL_LITERAL_DOUBLE, RASQAL_LITERAL_FLOAT, RASQAL_LITERAL_DECIMAL, RASQAL_LITERAL_DATETIME, /* internal */ RASQAL_LITERAL_FIRST_XSD = RASQAL_LITERAL_STRING, /* internal */ RASQAL_LITERAL_LAST_XSD = RASQAL_LITERAL_DATETIME, RASQAL_LITERAL_PATTERN, RASQAL_LITERAL_QNAME, RASQAL_LITERAL_VARIABLE, /* internal */ RASQAL_LITERAL_LAST= RASQAL_LITERAL_VARIABLE } rasqal_literal_type; Types of literal. The order in the enumeration is significant as it encodes the SPARQL term ordering conditions: Blank Nodes << IRIs << RDF literals << typed literals which coresponds to in enum values BLANK << URI << STRING << (BOOLEAN | INTEGER | DOUBLE | FLOAT | DECIMAL | DATETIME) (RASQAL_LITERAL_FIRST_XSD ... RASQAL_LITERAL_LAST_XSD) Not used (internal): PATTERN, QNAME, VARIABLE See rasqal_literal_compare() when used with flags RASQAL_COMPARE_XQUERY RASQAL_LITERAL_UNKNOWN Internal. RASQAL_LITERAL_BLANK RDF blank node literal (SPARQL r:bNode) RASQAL_LITERAL_URI RDF URI Literal (SPARQL r:URI) RASQAL_LITERAL_STRING RDF Literal / xsd:string (SPARQL r:Literal) RASQAL_LITERAL_BOOLEAN Boolean literal xsd:boolean. RASQAL_LITERAL_INTEGER Integer literal xsd:integer. RASQAL_LITERAL_DOUBLE Double floating point literal xsd:double. RASQAL_LITERAL_FLOAT Floating point literal xsd:float. RASQAL_LITERAL_DECIMAL Decimal integer xsd:decimal. RASQAL_LITERAL_DATETIME Date/Time literal xsd:dateTime. RASQAL_LITERAL_FIRST_XSD Internal. RASQAL_LITERAL_LAST_XSD Internal. RASQAL_LITERAL_PATTERN Pattern literal for a regex. RASQAL_LITERAL_QNAME XML Qname literal. RASQAL_LITERAL_VARIABLE Variable literal. RASQAL_LITERAL_LAST Internal. rasqal_new_typed_literalrasqal_literal* rasqal_new_typed_literal (rasqal_world *world, rasqal_literal_type type, unsigned char *string); Constructor - Create a new Rasqal integer literal from a string The integer decimal number is turned into a rasqal integer literal and given a datatype of xsd:integer world : rasqal world object type : Type of literal such as RASQAL_LITERAL_INTEGER or RASQAL_LITERAL_BOOLEAN string : lexical form - ownership not taken Returns : New rasqal_literal or NULL on failure rasqal_new_boolean_literalrasqal_literal* rasqal_new_boolean_literal (rasqal_world *world, int value); Constructor - Create a new Rasqal boolean literal. world : rasqal world object value : non-0 for true, 0 for false Returns : New rasqal_literal or NULL on failure rasqal_new_decimal_literalrasqal_literal* rasqal_new_decimal_literal (rasqal_world *world, unsigned char *string); Constructor - Create a new Rasqal decimal literal. world : rasqal world object string : decimal literal Returns : New rasqal_literal or NULL on failure rasqal_new_decimal_literal_from_decimalrasqal_literal* rasqal_new_decimal_literal_from_decimal (rasqal_world *world, unsigned char *string, rasqal_xsd_decimal *decimal); Constructor - Create a new Rasqal decimal literal. world : rasqal world object string : decimal literal string decimal : rasqal XSD Decimal Returns : New rasqal_literal or NULL on failure rasqal_new_double_literalrasqal_literal* rasqal_new_double_literal (rasqal_world *world, double d); Constructor - Create a new Rasqal double literal. world : rasqal world object d : double literal Returns : New rasqal_literal or NULL on failure rasqal_new_float_literalrasqal_literal* rasqal_new_float_literal (rasqal_world *world, float f); Constructor - Create a new Rasqal float literal. world : rasqal world object f : float literal Returns : New rasqal_literal or NULL on failure rasqal_new_integer_literalrasqal_literal* rasqal_new_integer_literal (rasqal_world *world, rasqal_literal_type type, int integer); Constructor - Create a new Rasqal integer literal. The integer decimal number is turned into a rasqal integer literal and given a datatype of xsd:integer world : rasqal world object type : Type of literal such as RASQAL_LITERAL_INTEGER or RASQAL_LITERAL_BOOLEAN integer : int value Returns : New rasqal_literal or NULL on failure rasqal_new_pattern_literalrasqal_literal* rasqal_new_pattern_literal (rasqal_world *world, unsigned char *pattern, const char *flags); Constructor - Create a new Rasqal pattern literal. The pattern and flags are input parameters and are stored in the literal, not copied. They are freed also on failure. The set of flags recognised depends on the regex engine and the query language. world : rasqal world object pattern : regex pattern flags : regex flags Returns : New rasqal_literal or NULL on failure rasqal_new_simple_literalrasqal_literal* rasqal_new_simple_literal (rasqal_world *world, rasqal_literal_type type, unsigned char *string); Constructor - Create a new Rasqal simple literal. The string is an input parameter and is stored in the literal, not copied. It is freed also on failure. world : rasqal world object type : RASQAL_LITERAL_BLANK or RASQAL_LITERAL_BLANK_QNAME string : the UTF-8 string value to store Returns : New rasqal_literal or NULL on failure rasqal_new_string_literalrasqal_literal* rasqal_new_string_literal (rasqal_world *world, unsigned char *string, const char *language, raptor_uri *datatype, unsigned char *datatype_qname); Constructor - Create a new Rasqal string literal. All parameters are input parameters and if present are stored in the literal, not copied. They are freed also on failure. The datatype and datatype_qname parameters are alternatives; the qname is a datatype that cannot be resolved till later since the prefixes have not yet been declared or checked. If the string literal is datatyped and of certain types recognised it may be converted to a different literal type by rasqal_literal_string_to_native() world : rasqal world object string : UTF-8 string lexical form language : RDF language (xml:lang) (or NULL) datatype : datatype URI (or NULL for plain literal) datatype_qname : datatype qname string (or NULL for plain literal) Returns : New rasqal_literal or NULL on failure rasqal_new_uri_literalrasqal_literal* rasqal_new_uri_literal (rasqal_world *world, raptor_uri *uri); Constructor - Create a new Rasqal URI literal from a raptor URI. The uri is an input parameter and is stored in the literal, not copied. The uri is freed also on failure. world : rasqal world object uri : raptor_uri uri Returns : New rasqal_literal or NULL on failure rasqal_new_variable_literalrasqal_literal* rasqal_new_variable_literal (rasqal_world *world, rasqal_variable *variable); Constructor - Create a new Rasqal variable literal. variable is an input parameter and stored in the literal, not copied. world : rasqal_world object variable : rasqal_variable to use Returns : New rasqal_literal or NULL on failure rasqal_new_literal_from_literalrasqal_literal* rasqal_new_literal_from_literal (rasqal_literal *l); Copy Constructor - create a new rasqal_literal object from an existing rasqal_literal object. l : rasqal_literal object to copy Returns : a new rasqal_literal object or NULL rasqal_free_literalvoid rasqal_free_literal (rasqal_literal *l); Destructor - destroy an rasqal_literal object. l : rasqal_literal object rasqal_literal_as_noderasqal_literal* rasqal_literal_as_node (rasqal_literal *l); Turn a literal into a new RDF string, URI or blank literal. l : rasqal_literal object Returns : the new rasqal_literal or NULL on failure rasqal_literal_as_stringconst unsigned char* rasqal_literal_as_string (rasqal_literal *l); Return the string format of a literal. l : rasqal_literal object Returns : pointer to a shared string format of the literal. rasqal_literal_as_string_flagsconst unsigned char* rasqal_literal_as_string_flags (rasqal_literal *l, int flags, int *error); Return the string format of a literal according to flags. flag bits affects conversion: RASQAL_COMPARE_XQUERY: use XQuery conversion rules If error is not NULL, *error is set to non-0 on error l : rasqal_literal object flags : comparison flags error : pointer to error Returns : pointer to a shared string format of the literal. rasqal_literal_as_variablerasqal_variable* rasqal_literal_as_variable (rasqal_literal *l); Get the variable inside a literal. l : rasqal_literal object Returns : the rasqal_variable or NULL if the literal is not a variable rasqal_literal_compareint rasqal_literal_compare (rasqal_literal *l1, rasqal_literal *l2, int flags, int *error); Compare two literals with type promotion. The two literals are compared across their range. If the types are not the same, they are promoted. If one is a double or float, the other is promoted to double, otherwise for integers, otherwise to strings (all literals have a string value). The comparison returned is as for strcmp, first before second returns <0. equal returns 0, and first after second returns >0. For URIs, the string value is used for the comparsion. flag bits affects comparisons: RASQAL_COMPARE_NOCASE: use case independent string comparisons RASQAL_COMPARE_XQUERY: use XQuery comparison and type promotion rules RASQAL_COMPARE_RDF: use RDF term comparison RASQAL_COMPARE_URI: allow comparison of URIs (typically for SPARQL ORDER) If error is not NULL, *error is set to non-0 on error l1 : rasqal_literal first literal l2 : rasqal_literal second literal flags : comparison flags error : pointer to error Returns : <0, 0, or >0 as described above. rasqal_literal_datatyperaptor_uri* rasqal_literal_datatype (rasqal_literal *l); Get the datatype URI of a literal l : rasqal_literal object Returns : shared pointer to raptor_uri of datatype or NULL on failure or no value rasqal_literal_equalsint rasqal_literal_equals (rasqal_literal *l1, rasqal_literal *l2); Compare two literals with no type promotion. If the l2 data literal value is a boolean, it will match the string "true" or "false" in the first literal l1. l1 : rasqal_literal literal l2 : rasqal_literal data literal Returns : non-0 if equal rasqal_literal_printvoid rasqal_literal_print (rasqal_literal *l, FILE *fh); Print a Rasqal literal in a debug format. The print debug format may change in any release. l : the rasqal_literal object fh : the FILE* handle to print to rasqal_literal_print_typevoid rasqal_literal_print_type (rasqal_literal *l, FILE *fh); Print a string form for a rasqal literal type. l : the rasqal_literal object fh : the FILE* handle to print to rasqal_literal_valuerasqal_literal* rasqal_literal_value (rasqal_literal *l); Get the literal value looking up any variables needed l : rasqal_literal object Returns : literal value or NULL if has no value