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.

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...

Enumerations
enum	clingo_symbol_type_e { 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
CLINGO_VISIBILITY_DEFAULT bool	clingo_add_string (char const string, char const *result)
	Internalize a string. More...

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

CLINGO_VISIBILITY_DEFAULT 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...

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

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

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

Typedef Documentation

◆ clingo_signature_t

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).

◆ clingo_symbol_t

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

◆ clingo_symbol_type_e

enum clingo_symbol_type_e

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

◆ clingo_add_string()

CLINGO_VISIBILITY_DEFAULT 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.

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

◆ clingo_parse_term()

CLINGO_VISIBILITY_DEFAULT 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

◆ clingo_signature_arity()

CLINGO_VISIBILITY_DEFAULT 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

◆ clingo_signature_create()

CLINGO_VISIBILITY_DEFAULT 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.

◆ clingo_signature_hash()

CLINGO_VISIBILITY_DEFAULT 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

◆ clingo_signature_is_equal_to()

CLINGO_VISIBILITY_DEFAULT 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

◆ clingo_signature_is_less_than()

CLINGO_VISIBILITY_DEFAULT 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

◆ clingo_signature_is_negative()

CLINGO_VISIBILITY_DEFAULT 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

◆ clingo_signature_is_positive()

CLINGO_VISIBILITY_DEFAULT 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

◆ clingo_signature_name()

CLINGO_VISIBILITY_DEFAULT const char* clingo_signature_name ( clingo_signature_t signature )

Get the name of a signature.

Note: The string is internalized and valid for the duration of the process.

Parameters

[in] signature the target signature

Returns: the name of the signature

◆ clingo_symbol_arguments()

CLINGO_VISIBILITY_DEFAULT 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.

◆ clingo_symbol_create_function()

CLINGO_VISIBILITY_DEFAULT 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.

◆ clingo_symbol_create_id()

CLINGO_VISIBILITY_DEFAULT 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.

◆ clingo_symbol_create_infimum()

CLINGO_VISIBILITY_DEFAULT void clingo_symbol_create_infimum ( clingo_symbol_t * symbol )

Construct a symbol representing #inf.

Parameters

[out] symbol the resulting symbol

◆ clingo_symbol_create_number()

CLINGO_VISIBILITY_DEFAULT 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.

◆ clingo_symbol_create_string()

CLINGO_VISIBILITY_DEFAULT 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

◆ clingo_symbol_create_supremum()

CLINGO_VISIBILITY_DEFAULT void clingo_symbol_create_supremum ( clingo_symbol_t * symbol )

Construct a symbol representing #sup.

Parameters

[out] symbol the resulting symbol

◆ clingo_symbol_hash()

CLINGO_VISIBILITY_DEFAULT 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.

◆ clingo_symbol_is_equal_to()

CLINGO_VISIBILITY_DEFAULT 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.

◆ clingo_symbol_is_less_than()

CLINGO_VISIBILITY_DEFAULT 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.

◆ clingo_symbol_is_negative()

CLINGO_VISIBILITY_DEFAULT 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

◆ clingo_symbol_is_positive()

CLINGO_VISIBILITY_DEFAULT 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

◆ clingo_symbol_name()

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

Get the name of a symbol.

Note: The string is internalized and valid for the duration of the process.

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

◆ clingo_symbol_number()

CLINGO_VISIBILITY_DEFAULT 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.

◆ clingo_symbol_string()

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

Get the string of a symbol.

Note: The string is internalized and valid for the duration of the process.

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

◆ clingo_symbol_to_string()

CLINGO_VISIBILITY_DEFAULT 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, statistics.c, symbol.c, symbolic-atoms.c, and theory-atoms.c.

◆ clingo_symbol_to_string_size()

CLINGO_VISIBILITY_DEFAULT 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, statistics.c, symbol.c, symbolic-atoms.c, and theory-atoms.c.

◆ clingo_symbol_type()

CLINGO_VISIBILITY_DEFAULT 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

Typedefs

Enumerations

Functions

Signature Functions

Symbol Construction Functions

Symbol Inspection Functions

Symbol Comparison Functions

Typedef Documentation

◆ clingo_signature_t

◆ clingo_symbol_t

Enumeration Type Documentation

◆ clingo_symbol_type_e

Function Documentation

◆ clingo_add_string()

◆ clingo_parse_term()

◆ clingo_signature_arity()

◆ clingo_signature_create()

◆ clingo_signature_hash()

◆ clingo_signature_is_equal_to()

◆ clingo_signature_is_less_than()

◆ clingo_signature_is_negative()

◆ clingo_signature_is_positive()

◆ clingo_signature_name()

◆ clingo_symbol_arguments()

◆ clingo_symbol_create_function()

◆ clingo_symbol_create_id()

◆ clingo_symbol_create_infimum()

◆ clingo_symbol_create_number()

◆ clingo_symbol_create_string()

◆ clingo_symbol_create_supremum()

◆ clingo_symbol_hash()

◆ clingo_symbol_is_equal_to()

◆ clingo_symbol_is_less_than()

◆ clingo_symbol_is_negative()

◆ clingo_symbol_is_positive()

◆ clingo_symbol_name()

◆ clingo_symbol_number()

◆ clingo_symbol_string()

◆ clingo_symbol_to_string()

◆ clingo_symbol_to_string_size()

◆ clingo_symbol_type()