rasqal_variable

typedef 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_new_variable ()

rasqal_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

rasqal_new_variable_typed ()

rasqal_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

rasqal_new_variable_from_variable ()

rasqal_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

rasqal_free_variable ()

void                rasqal_free_variable                (rasqal_variable *v);

Destructor - Destroy a Rasqal variable object.

rasqal_variable_print ()

void                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.

rasqal_variable_set_value ()

void                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.

enum rasqal_variable_type

typedef 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.