Detailed Description

Working with (evaluated) ground terms and related functions.

Note: All functions in this module are thread-safe.

For an example, see symbol.c.

Classes
struct	clingo_symbolic_literal
	Represents a symbolic literal. More...

Typedefs
typedef uint64_t	clingo_signature_t
	Represents a predicate signature. More...

typedef int	clingo_symbol_type_t
	Corresponding type to clingo_symbol_type.

typedef uint64_t	clingo_symbol_t
	Represents a symbol. More...

typedef struct clingo_symbolic_literal	clingo_symbolic_literal_t
	Represents a symbolic literal.

Enumerations
enum	clingo_symbol_type { clingo_symbol_type_infimum = 0, clingo_symbol_type_number = 1, clingo_symbol_type_string = 4, clingo_symbol_type_function = 5, clingo_symbol_type_supremum = 7 }
	Enumeration of available symbol types. More...

Functions
bool	clingo_add_string (char const string, char const *result)
	Internalize a string. More...

bool	clingo_parse_term (char const string, clingo_logger_t logger, void logger_data, unsigned message_limit, clingo_symbol_t symbol)
	Parse a term in string form. More...

Signature Functions
bool	clingo_signature_create (char const name, uint32_t arity, bool positive, clingo_signature_t signature)
	Create a new signature. More...

char const *	clingo_signature_name (clingo_signature_t signature)
	Get the name of a signature. More...

uint32_t	clingo_signature_arity (clingo_signature_t signature)
	Get the arity of a signature. More...

bool	clingo_signature_is_positive (clingo_signature_t signature)
	Whether the signature is positive (is not classically negated). More...

bool	clingo_signature_is_negative (clingo_signature_t signature)
	Whether the signature is negative (is classically negated). More...

bool	clingo_signature_is_equal_to (clingo_signature_t a, clingo_signature_t b)
	Check if two signatures are equal. More...

bool	clingo_signature_is_less_than (clingo_signature_t a, clingo_signature_t b)
	Check if a signature is less than another signature. More...

size_t	clingo_signature_hash (clingo_signature_t signature)
	Calculate a hash code of a signature. More...

Symbol Construction Functions
void	clingo_symbol_create_number (int number, clingo_symbol_t *symbol)
	Construct a symbol representing a number. More...

void	clingo_symbol_create_supremum (clingo_symbol_t *symbol)
	Construct a symbol representing #sup. More...

void	clingo_symbol_create_infimum (clingo_symbol_t *symbol)
	Construct a symbol representing `#inf`. More...

bool	clingo_symbol_create_string (char const string, clingo_symbol_t symbol)
	Construct a symbol representing a string. More...

bool	clingo_symbol_create_id (char const name, bool positive, clingo_symbol_t symbol)
	Construct a symbol representing an id. More...

bool	clingo_symbol_create_function (char const name, clingo_symbol_t const arguments, size_t arguments_size, bool positive, clingo_symbol_t *symbol)
	Construct a symbol representing a function or tuple. More...

Symbol Inspection Functions
bool	clingo_symbol_number (clingo_symbol_t symbol, int *number)
	Get the number of a symbol. More...

bool	clingo_symbol_name (clingo_symbol_t symbol, char const **name)
	Get the name of a symbol. More...

bool	clingo_symbol_string (clingo_symbol_t symbol, char const **string)
	Get the string of a symbol. More...

bool	clingo_symbol_is_positive (clingo_symbol_t symbol, bool *positive)
	Check if a function is positive (does not have a sign). More...

bool	clingo_symbol_is_negative (clingo_symbol_t symbol, bool *negative)
	Check if a function is negative (has a sign). More...

bool	clingo_symbol_arguments (clingo_symbol_t symbol, clingo_symbol_t const *arguments, size_t arguments_size)
	Get the arguments of a symbol. More...

clingo_symbol_type_t	clingo_symbol_type (clingo_symbol_t symbol)
	Get the type of a symbol. More...

bool	clingo_symbol_to_string_size (clingo_symbol_t symbol, size_t *size)
	Get the size of the string representation of a symbol (including the terminating 0). More...

bool	clingo_symbol_to_string (clingo_symbol_t symbol, char *string, size_t size)
	Get the string representation of a symbol. More...

Symbol Comparison Functions
bool	clingo_symbol_is_equal_to (clingo_symbol_t a, clingo_symbol_t b)
	Check if two symbols are equal. More...

bool	clingo_symbol_is_less_than (clingo_symbol_t a, clingo_symbol_t b)
	Check if a symbol is less than another symbol. More...

size_t	clingo_symbol_hash (clingo_symbol_t symbol)
	Calculate a hash code of a symbol. More...

Typedef Documentation

typedef uint64_t clingo_signature_t

Represents a predicate signature.

Signatures have a name and an arity, and can be positive or negative (to represent classical negation).

typedef uint64_t clingo_symbol_t

Represents a symbol.

This includes numbers, strings, functions (including constants when arguments are empty and tuples when the name is empty), #inf and #sup.

Enumeration Type Documentation

enum clingo_symbol_type

Enumeration of available symbol types.

Enumerator
clingo_symbol_type_infimum	the `#inf` symbol
clingo_symbol_type_number	a numeric symbol, e.g., `1`
clingo_symbol_type_string	a string symbol, e.g., `"a"`
clingo_symbol_type_function	a numeric symbol, e.g., `c`, `(1, "a")`, or `f(1,"a")`
clingo_symbol_type_supremum	the `#sup` symbol

Function Documentation

bool clingo_add_string	(	char const *	string,
		char const **	result
	)

Internalize a string.

This functions takes a string as input and returns an equal unique string that is (at the moment) not freed until the program is closed. All strings returned from clingo API functions are internalized and must not be freed.

Parameters

[in]	string	the string to internalize
[out]	result	the internalized string

Returns

whether the call was successful; might set one of the following error codes:

clingo_error_bad_alloc

bool clingo_parse_term	(	char const *	string,
		clingo_logger_t *	logger,
		void *	logger_data,
		unsigned	message_limit,
		clingo_symbol_t *	symbol
	)

Parse a term in string form.

The result of this function is a symbol. The input term can contain unevaluated functions, which are evaluated during parsing.

Parameters

[in]	string	the string to parse
[in]	logger	optional logger to report warnings during parsing
[in]	logger_data	user data for the logger
[in]	message_limit	maximum number of times to call the logger
[out]	symbol	the resulting symbol

Returns

whether the call was successful; might set one of the following error codes:

clingo_error_bad_alloc
clingo_error_runtime if parsing fails

uint32_t clingo_signature_arity ( clingo_signature_t signature )

Get the arity of a signature.

Parameters

[in] signature the target signature

Returns: the arity of the signature

bool clingo_signature_create	(	char const *	name,
		uint32_t	arity,
		bool	positive,
		clingo_signature_t *	signature
	)

Create a new signature.

Parameters

[in]	name	name of the signature
[in]	arity	arity of the signature
[in]	positive	false if the signature has a classical negation sign
[out]	signature	the resulting signature

Returns

whether the call was successful; might set one of the following error codes:

clingo_error_bad_alloc

Examples:: propagator.c.

size_t clingo_signature_hash ( clingo_signature_t signature )

Calculate a hash code of a signature.

Parameters

[in] signature the target signature

Returns: the hash code of the signature

bool clingo_signature_is_equal_to	(	clingo_signature_t	a,
		clingo_signature_t	b
	)

Check if two signatures are equal.

Parameters

[in]	a	first signature
[in]	b	second signature

Returns: whether a == b

bool clingo_signature_is_less_than	(	clingo_signature_t	a,
		clingo_signature_t	b
	)

Check if a signature is less than another signature.

Signatures are compared first by sign (unsigned < signed), then by arity, then by name.

Parameters

[in]	a	first signature
[in]	b	second signature

Returns: whether a < b

bool clingo_signature_is_negative ( clingo_signature_t signature )

Whether the signature is negative (is classically negated).

Parameters

[in] signature the target signature

Returns: whether the signature has a sign

bool clingo_signature_is_positive ( clingo_signature_t signature )

Whether the signature is positive (is not classically negated).

Parameters

[in] signature the target signature

Returns: whether the signature has no sign

char const* clingo_signature_name ( clingo_signature_t signature )

Get the name of a signature.

Parameters

[in] signature the target signature

Returns: the name of the signature

bool clingo_symbol_arguments	(	clingo_symbol_t	symbol,
		clingo_symbol_t const **	arguments,
		size_t *	arguments_size
	)

Get the arguments of a symbol.

Parameters

[in]	symbol	the target symbol
[out]	arguments	the resulting arguments
[out]	arguments_size	the number of arguments

Returns

whether the call was successful; might set one of the following error codes:

clingo_error_runtime if symbol is not of type clingo_symbol_type_function

Examples:: propagator.c, and symbol.c.

bool clingo_symbol_create_function	(	char const *	name,
		clingo_symbol_t const *	arguments,
		size_t	arguments_size,
		bool	positive,
		clingo_symbol_t *	symbol
	)

Construct a symbol representing a function or tuple.

Note: To create tuples, the empty string has to be used as name.

Parameters

[in]	name	the name of the function
[in]	arguments	the arguments of the function
[in]	arguments_size	the number of arguments
[in]	positive	whether the symbol has a classical negation sign
[out]	symbol	the resulting symbol

Returns

whether the call was successful; might set one of the following error codes:

clingo_error_bad_alloc

Examples:: symbol.c.

bool clingo_symbol_create_id	(	char const *	name,
		bool	positive,
		clingo_symbol_t *	symbol
	)

Construct a symbol representing an id.

Note: This is just a shortcut for clingo_symbol_create_function() with empty arguments.

Parameters

[in]	name	the name
[in]	positive	whether the symbol has a classical negation sign
[out]	symbol	the resulting symbol

Returns

whether the call was successful; might set one of the following error codes:

clingo_error_bad_alloc

Examples:: ast.c, backend.c, and symbol.c.

void clingo_symbol_create_infimum ( clingo_symbol_t * symbol )

Construct a symbol representing #inf.

Parameters

[out] symbol the resulting symbol

void clingo_symbol_create_number	(	int	number,
		clingo_symbol_t *	symbol
	)

Construct a symbol representing a number.

Parameters

[in]	number	the number
[out]	symbol	the resulting symbol

Examples:: propagator.c, and symbol.c.

bool clingo_symbol_create_string	(	char const *	string,
		clingo_symbol_t *	symbol
	)

Construct a symbol representing a string.

Parameters

[in]	string	the string
[out]	symbol	the resulting symbol

Returns

whether the call was successful; might set one of the following error codes:

clingo_error_bad_alloc

void clingo_symbol_create_supremum ( clingo_symbol_t * symbol )

Construct a symbol representing #sup.

Parameters

[out] symbol the resulting symbol

size_t clingo_symbol_hash ( clingo_symbol_t symbol )

Calculate a hash code of a symbol.

Parameters

[in] symbol the target symbol

Returns: the hash code of the symbol

Examples:: symbol.c.

bool clingo_symbol_is_equal_to	(	clingo_symbol_t	a,
		clingo_symbol_t	b
	)

Check if two symbols are equal.

Parameters

[in]	a	first symbol
[in]	b	second symbol

Returns: whether a == b

Examples:: symbol.c.

bool clingo_symbol_is_less_than	(	clingo_symbol_t	a,
		clingo_symbol_t	b
	)

Check if a symbol is less than another symbol.

Symbols are first compared by type. If the types are equal, the values are compared (where strings are compared using strcmp). Functions are first compared by signature and then lexicographically by arguments.

Parameters

[in]	a	first symbol
[in]	b	second symbol

Returns: whether a < b

Examples:: symbol.c.

bool clingo_symbol_is_negative	(	clingo_symbol_t	symbol,
		bool *	negative
	)

Check if a function is negative (has a sign).

Parameters

[in]	symbol	the target symbol
[out]	negative	the result

Returns

whether the call was successful; might set one of the following error codes:

clingo_error_runtime if symbol is not of type clingo_symbol_type_function

bool clingo_symbol_is_positive	(	clingo_symbol_t	symbol,
		bool *	positive
	)

Check if a function is positive (does not have a sign).

Parameters

[in]	symbol	the target symbol
[out]	positive	the result

Returns

whether the call was successful; might set one of the following error codes:

clingo_error_runtime if symbol is not of type clingo_symbol_type_function

bool clingo_symbol_name	(	clingo_symbol_t	symbol,
		char const **	name
	)

Get the name of a symbol.

Parameters

[in]	symbol	the target symbol
[out]	name	the resulting name

Returns

whether the call was successful; might set one of the following error codes:

clingo_error_runtime if symbol is not of type clingo_symbol_type_function

bool clingo_symbol_number	(	clingo_symbol_t	symbol,
		int *	number
	)

Get the number of a symbol.

Parameters

[in]	symbol	the target symbol
[out]	number	the resulting number

Returns

whether the call was successful; might set one of the following error codes:

clingo_error_runtime if symbol is not of type clingo_symbol_type_number

Examples:: propagator.c.

bool clingo_symbol_string	(	clingo_symbol_t	symbol,
		char const **	string
	)

Get the string of a symbol.

Parameters

[in]	symbol	the target symbol
[out]	string	the resulting string

Returns

whether the call was successful; might set one of the following error codes:

clingo_error_runtime if symbol is not of type clingo_symbol_type_string

bool clingo_symbol_to_string	(	clingo_symbol_t	symbol,
		char *	string,
		size_t	size
	)

Get the string representation of a symbol.

Parameters

[in]	symbol	the target symbol
[out]	string	the resulting string
[in]	size	the size of the string

Returns

whether the call was successful; might set one of the following error codes:

clingo_error_bad_alloc

See also: clingo_symbol_to_string_size()

Examples:: ast.c, backend.c, configuration.c, control.c, model.c, propagator.c, solve-async.c, solve-iteratively.c, statistics.c, symbol.c, symbolic-atoms.c, and theory-atoms.c.

bool clingo_symbol_to_string_size	(	clingo_symbol_t	symbol,
		size_t *	size
	)

Get the size of the string representation of a symbol (including the terminating 0).

Parameters

[in]	symbol	the target symbol
[out]	size	the resulting size

Returns

whether the call was successful; might set one of the following error codes:

clingo_error_bad_alloc

Examples:: ast.c, backend.c, configuration.c, control.c, model.c, propagator.c, solve-async.c, solve-iteratively.c, statistics.c, symbol.c, symbolic-atoms.c, and theory-atoms.c.

clingo_symbol_type_t clingo_symbol_type ( clingo_symbol_t symbol )

Get the type of a symbol.

Parameters

[in] symbol the target symbol

Returns: the type of the symbol

Detailed Description

Classes

Typedefs

Enumerations

Functions

Signature Functions

Symbol Construction Functions

Symbol Inspection Functions

Symbol Comparison Functions

Typedef Documentation

Enumeration Type Documentation

Function Documentation