]> Variables 3 RASQAL Library Variables Variable with names and literal value. rasqal_variable; rasqal_variable* rasqal_new_variable (rasqal_query *rq, unsigned char *name, rasqal_literal *value); rasqal_variable* rasqal_new_variable_typed (rasqal_query *rq, rasqal_variable_type type, unsigned char *name, rasqal_literal *value); rasqal_variable* rasqal_new_variable_from_variable (rasqal_variable *v); void rasqal_free_variable (rasqal_variable *v); void rasqal_variable_print (rasqal_variable *v, FILE *fh); void rasqal_variable_set_value (rasqal_variable *v, rasqal_literal *l); enum rasqal_variable_type; A class to hold a variable with optional name and a rasqal_literal value. The name is not required for SPARQL anonymous variables, when constructed with rasqal_new_variable_typed() and type RASQAL_VARIABLE_TYPE_ANONYMOUS. rasqal_variabletypedef struct { const unsigned char *name; rasqal_literal* value; int offset; rasqal_variable_type type; struct rasqal_expression_s* expression; } rasqal_variable; Binding between a variable name and a value. Includes internal field offset for recording the offset into the (internal) rasqal_query variables array. rasqal_literal *value; Variable value or NULL if unbound. int offset; Internal. rasqal_variable_type type; Variable type. struct rasqal_expression_s *expression; Expression when the variable is a computed SELECT expression rasqal_new_variablerasqal_variable* rasqal_new_variable (rasqal_query *rq, unsigned char *name, rasqal_literal *value); Constructor - Create a new Rasqal normal variable. The variable must be associated with a query, since variable names are only significant with a single query. This creates a regular variable that can be returned of type RASQAL_VARIABLE_TYPE_NORMAL. Use rasqal_new_variable_typed to create other variables. The name and value become owned by the rasqal_variable structure rq : rasqal_query to associate the variable with name : variable name value : variable rasqal_literal value (or NULL) Returns : a new rasqal_variable or NULL on failure. rasqal_new_variable_typedrasqal_variable* rasqal_new_variable_typed (rasqal_query *rq, rasqal_variable_type type, unsigned char *name, rasqal_literal *value); Constructor - Create a new typed Rasqal variable. The variable must be associated with a query, since variable names are only significant with a single query. The name and value become owned by the rasqal_variable structure rq : rasqal_query to associate the variable with type : variable type defined by enumeration rasqal_variable_type name : variable name value : variable rasqal_literal value (or NULL) Returns : a new rasqal_variable or NULL on failure. rasqal_new_variable_from_variablerasqal_variable* rasqal_new_variable_from_variable (rasqal_variable *v); Copy Constructor - Create a new Rasqal variable from an existing one This does a deep copy of all variable fields v : rasqal_variable to copy Returns : a new rasqal_variable or NULL on failure. rasqal_free_variablevoid rasqal_free_variable (rasqal_variable *v); Destructor - Destroy a Rasqal variable object. v : rasqal_variable object rasqal_variable_printvoid rasqal_variable_print (rasqal_variable *v, FILE *fh); Print a Rasqal variable in a debug format. The print debug format may change in any release. v : the rasqal_variable object fh : the FILE* handle to print to rasqal_variable_set_valuevoid rasqal_variable_set_value (rasqal_variable *v, rasqal_literal *l); Set the value of a Rasqal variable. The variable value is an input parameter and is copied in, not shared. If the variable value is NULL, any existing value is deleted. v : the rasqal_variable object l : the rasqal_literal value to set (or NULL) rasqal_variable_typetypedef enum { RASQAL_VARIABLE_TYPE_UNKNOWN = 0, RASQAL_VARIABLE_TYPE_NORMAL = 1, RASQAL_VARIABLE_TYPE_ANONYMOUS = 2 } rasqal_variable_type; Rasqal variable types. ANONYMOUS can be used in queries but cannot be returned in a result. RASQAL_VARIABLE_TYPE_UNKNOWN Internal. RASQAL_VARIABLE_TYPE_NORMAL The regular variable type. RASQAL_VARIABLE_TYPE_ANONYMOUS Anonymous variable type.