Detailed Description

Add non-ground program representations (ASTs) to logic programs or extend the ground (aspif) program.

For an example about ground logic programs, see backend.c. For an example about non-ground logic programs, see ast.c and the Abstract Syntax Trees module.

Typedefs
typedef int	clingo_theory_sequence_type_t
	Corresponding type to clingo_theory_sequence_type_e.

typedef struct clingo_backend	clingo_backend_t
	Handle to the backend to add directives in aspif format.

Enumerations
enum	clingo_theory_sequence_type_e { clingo_theory_sequence_type_tuple, clingo_theory_sequence_type_list, clingo_theory_sequence_type_set }
	Enumeration of theory sequence types. More...

Functions
CLINGO_VISIBILITY_DEFAULT bool	clingo_backend_begin (clingo_backend_t *backend)
	Prepare the backend for usage. More...

CLINGO_VISIBILITY_DEFAULT bool	clingo_backend_end (clingo_backend_t *backend)
	Finalize the backend after using it. More...

CLINGO_VISIBILITY_DEFAULT bool	clingo_backend_rule (clingo_backend_t backend, bool choice, clingo_atom_t const head, size_t head_size, clingo_literal_t const *body, size_t body_size)
	Add a rule to the program. More...

CLINGO_VISIBILITY_DEFAULT bool	clingo_backend_weight_rule (clingo_backend_t backend, bool choice, clingo_atom_t const head, size_t head_size, clingo_weight_t lower_bound, clingo_weighted_literal_t const *body, size_t body_size)
	Add a weight rule to the program. More...

CLINGO_VISIBILITY_DEFAULT bool	clingo_backend_minimize (clingo_backend_t backend, clingo_weight_t priority, clingo_weighted_literal_t const literals, size_t size)
	Add a minimize constraint (or weak constraint) to the program. More...

CLINGO_VISIBILITY_DEFAULT bool	clingo_backend_project (clingo_backend_t backend, clingo_atom_t const atoms, size_t size)
	Add a projection directive. More...

CLINGO_VISIBILITY_DEFAULT bool	clingo_backend_external (clingo_backend_t *backend, clingo_atom_t atom, clingo_external_type_t type)
	Add an external statement. More...

CLINGO_VISIBILITY_DEFAULT bool	clingo_backend_assume (clingo_backend_t backend, clingo_literal_t const literals, size_t size)
	Add an assumption directive. More...

CLINGO_VISIBILITY_DEFAULT bool	clingo_backend_heuristic (clingo_backend_t backend, clingo_atom_t atom, clingo_heuristic_type_t type, int bias, unsigned priority, clingo_literal_t const condition, size_t size)
	Add an heuristic directive. More...

CLINGO_VISIBILITY_DEFAULT bool	clingo_backend_acyc_edge (clingo_backend_t backend, int node_u, int node_v, clingo_literal_t const condition, size_t size)
	Add an edge directive. More...

CLINGO_VISIBILITY_DEFAULT bool	clingo_backend_add_atom (clingo_backend_t backend, clingo_symbol_t symbol, clingo_atom_t *atom)
	Get a fresh atom to be used in aspif directives. More...

CLINGO_VISIBILITY_DEFAULT bool	clingo_backend_theory_term_number (clingo_backend_t backend, int number, clingo_id_t term_id)
	Add a numeric theory term. More...

CLINGO_VISIBILITY_DEFAULT bool	clingo_backend_theory_term_string (clingo_backend_t backend, char const string, clingo_id_t *term_id)
	Add a theory term representing a string. More...

CLINGO_VISIBILITY_DEFAULT bool	clingo_backend_theory_term_sequence (clingo_backend_t backend, clingo_theory_sequence_type_t type, clingo_id_t const arguments, size_t size, clingo_id_t *term_id)
	Add a theory term representing a sequence of theory terms. More...

CLINGO_VISIBILITY_DEFAULT bool	clingo_backend_theory_term_function (clingo_backend_t backend, char const name, clingo_id_t const arguments, size_t size, clingo_id_t term_id)
	Add a theory term representing a function. More...

CLINGO_VISIBILITY_DEFAULT bool	clingo_backend_theory_term_symbol (clingo_backend_t backend, clingo_symbol_t symbol, clingo_id_t term_id)
	Convert the given symbol into a theory term. More...

CLINGO_VISIBILITY_DEFAULT bool	clingo_backend_theory_element (clingo_backend_t backend, clingo_id_t const tuple, size_t tuple_size, clingo_literal_t const condition, size_t condition_size, clingo_id_t element_id)
	Add a theory atom element. More...

CLINGO_VISIBILITY_DEFAULT bool	clingo_backend_theory_atom (clingo_backend_t backend, clingo_atom_t atom_id_or_zero, clingo_id_t term_id, clingo_id_t const elements, size_t size)
	Add a theory atom without a guard. More...

CLINGO_VISIBILITY_DEFAULT bool	clingo_backend_theory_atom_with_guard (clingo_backend_t backend, clingo_atom_t atom_id_or_zero, clingo_id_t term_id, clingo_id_t const elements, size_t size, char const *operator_name, clingo_id_t right_hand_side_id)
	Add a theory atom with a guard. More...

Enumeration Type Documentation

◆ clingo_theory_sequence_type_e

enum clingo_theory_sequence_type_e

Enumeration of theory sequence types.

Enumerator
clingo_theory_sequence_type_tuple	Theory tuples "(t1,...,tn)".
clingo_theory_sequence_type_list	Theory lists "[t1,...,tn]".
clingo_theory_sequence_type_set	Theory sets "{t1,...,tn}".

Function Documentation

◆ clingo_backend_acyc_edge()

CLINGO_VISIBILITY_DEFAULT bool clingo_backend_acyc_edge	(	clingo_backend_t *	backend,
		int	node_u,
		int	node_v,
		clingo_literal_t const *	condition,
		size_t	size
	)

Add an edge directive.

Parameters

[in]	backend	the target backend
[in]	node_u	the start vertex of the edge
[in]	node_v	the end vertex of the edge
[in]	condition	the condition under which the edge is part of the graph
[in]	size	the number of atoms in the condition

Returns

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

clingo_error_bad_alloc

◆ clingo_backend_add_atom()

CLINGO_VISIBILITY_DEFAULT bool clingo_backend_add_atom	(	clingo_backend_t *	backend,
		clingo_symbol_t *	symbol,
		clingo_atom_t *	atom
	)

Get a fresh atom to be used in aspif directives.

Parameters

[in]	backend	the target backend
[in]	symbol	optional symbol to associate the atom with
[out]	atom	the resulting atom

Returns: whether the call was successful

Examples: backend.c.

◆ clingo_backend_assume()

CLINGO_VISIBILITY_DEFAULT bool clingo_backend_assume	(	clingo_backend_t *	backend,
		clingo_literal_t const *	literals,
		size_t	size
	)

Add an assumption directive.

Parameters

[in]	backend	the target backend
[in]	literals	the literals to assume (positive literals are true and negative literals false for the next solve call)
[in]	size	the number of atoms

Returns

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

clingo_error_bad_alloc

◆ clingo_backend_begin()

CLINGO_VISIBILITY_DEFAULT bool clingo_backend_begin ( clingo_backend_t * backend )

Prepare the backend for usage.

Parameters

[in] backend the target backend

Returns

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

Examples: backend.c.

◆ clingo_backend_end()

CLINGO_VISIBILITY_DEFAULT bool clingo_backend_end ( clingo_backend_t * backend )

Finalize the backend after using it.

Parameters

[in] backend the target backend

Returns

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

Examples: backend.c.

◆ clingo_backend_external()

CLINGO_VISIBILITY_DEFAULT bool clingo_backend_external	(	clingo_backend_t *	backend,
		clingo_atom_t	atom,
		clingo_external_type_t	type
	)

Add an external statement.

Parameters

[in]	backend	the target backend
[in]	atom	the external atom
[in]	type	the type of the external statement

Returns

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

clingo_error_bad_alloc

◆ clingo_backend_heuristic()

CLINGO_VISIBILITY_DEFAULT bool clingo_backend_heuristic	(	clingo_backend_t *	backend,
		clingo_atom_t	atom,
		clingo_heuristic_type_t	type,
		int	bias,
		unsigned	priority,
		clingo_literal_t const *	condition,
		size_t	size
	)

Add an heuristic directive.

Parameters

[in]	backend	the target backend
[in]	atom	the target atom
[in]	type	the type of the heuristic modification
[in]	bias	the heuristic bias
[in]	priority	the heuristic priority
[in]	condition	the condition under which to apply the heuristic modification
[in]	size	the number of atoms in the condition

Returns

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

clingo_error_bad_alloc

◆ clingo_backend_minimize()

CLINGO_VISIBILITY_DEFAULT bool clingo_backend_minimize	(	clingo_backend_t *	backend,
		clingo_weight_t	priority,
		clingo_weighted_literal_t const *	literals,
		size_t	size
	)

Add a minimize constraint (or weak constraint) to the program.

Parameters

[in]	backend	the target backend
[in]	priority	the priority of the constraint
[in]	literals	the weighted literals whose sum to minimize
[in]	size	the number of weighted literals

Returns

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

clingo_error_bad_alloc

◆ clingo_backend_project()

CLINGO_VISIBILITY_DEFAULT bool clingo_backend_project	(	clingo_backend_t *	backend,
		clingo_atom_t const *	atoms,
		size_t	size
	)

Add a projection directive.

Parameters

[in]	backend	the target backend
[in]	atoms	the atoms to project on
[in]	size	the number of atoms

Returns

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

clingo_error_bad_alloc

◆ clingo_backend_rule()

CLINGO_VISIBILITY_DEFAULT bool clingo_backend_rule	(	clingo_backend_t *	backend,
		bool	choice,
		clingo_atom_t const *	head,
		size_t	head_size,
		clingo_literal_t const *	body,
		size_t	body_size
	)

Add a rule to the program.

Parameters

[in]	backend	the target backend
[in]	choice	determines if the head is a choice or a disjunction
[in]	head	the head atoms
[in]	head_size	the number of atoms in the head
[in]	body	the body literals
[in]	body_size	the number of literals in the body

Returns

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

clingo_error_bad_alloc

Examples: backend.c.

◆ clingo_backend_theory_atom()

CLINGO_VISIBILITY_DEFAULT bool clingo_backend_theory_atom	(	clingo_backend_t *	backend,
		clingo_atom_t	atom_id_or_zero,
		clingo_id_t	term_id,
		clingo_id_t const *	elements,
		size_t	size
	)

Add a theory atom without a guard.

Parameters

[in]	backend	the target backend
[in]	atom_id_or_zero	a program atom or zero for theory directives
[in]	term_id	the term id of the term associated with the theory atom
[in]	elements	an array of element ids for the theory atoms's elements
[in]	size	the number of elements

Returns

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

clingo_error_bad_alloc

◆ clingo_backend_theory_atom_with_guard()

CLINGO_VISIBILITY_DEFAULT bool clingo_backend_theory_atom_with_guard	(	clingo_backend_t *	backend,
		clingo_atom_t	atom_id_or_zero,
		clingo_id_t	term_id,
		clingo_id_t const *	elements,
		size_t	size,
		char const *	operator_name,
		clingo_id_t	right_hand_side_id
	)

Add a theory atom with a guard.

Parameters

[in]	backend	the target backend
[in]	atom_id_or_zero	a program atom or zero for theory directives
[in]	term_id	the term id of the term associated with the theory atom
[in]	elements	an array of element ids for the theory atoms's elements
[in]	size	the number of elements
[in]	operator_name	the string representation of a theory operator
[in]	right_hand_side_id	the term id of the right hand side term

Returns

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

clingo_error_bad_alloc

◆ clingo_backend_theory_element()

CLINGO_VISIBILITY_DEFAULT bool clingo_backend_theory_element	(	clingo_backend_t *	backend,
		clingo_id_t const *	tuple,
		size_t	tuple_size,
		clingo_literal_t const *	condition,
		size_t	condition_size,
		clingo_id_t *	element_id
	)

Add a theory atom element.

Parameters

[in]	backend	the target backend
[in]	tuple	the array of term ids represeting the tuple
[in]	tuple_size	the size of the tuple
[in]	condition	an array of program literals represeting the condition
[in]	condition_size	the size of the condition
[out]	element_id	the resulting element id

Returns

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

clingo_error_bad_alloc

◆ clingo_backend_theory_term_function()

CLINGO_VISIBILITY_DEFAULT bool clingo_backend_theory_term_function	(	clingo_backend_t *	backend,
		char const *	name,
		clingo_id_t const *	arguments,
		size_t	size,
		clingo_id_t *	term_id
	)

Add a theory term representing a function.

Parameters

[in]	backend	the target backend
[in]	name	the name of the function
[in]	arguments	an array of term ids for the theory terms in the arguments
[in]	size	the number of arguments
[out]	term_id	the resulting term id

Returns

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

clingo_error_bad_alloc

◆ clingo_backend_theory_term_number()

CLINGO_VISIBILITY_DEFAULT bool clingo_backend_theory_term_number	(	clingo_backend_t *	backend,
		int	number,
		clingo_id_t *	term_id
	)

Add a numeric theory term.

Parameters

[in]	backend	the target backend
[in]	number	the value of the term
[out]	term_id	the resulting term id

Returns

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

clingo_error_bad_alloc

◆ clingo_backend_theory_term_sequence()

CLINGO_VISIBILITY_DEFAULT bool clingo_backend_theory_term_sequence	(	clingo_backend_t *	backend,
		clingo_theory_sequence_type_t	type,
		clingo_id_t const *	arguments,
		size_t	size,
		clingo_id_t *	term_id
	)

Add a theory term representing a sequence of theory terms.

Parameters

[in]	backend	the target backend
[in]	type	the type of the sequence
[in]	arguments	the term ids of the terms in the sequence
[in]	size	the number of elements of the sequence
[out]	term_id	the resulting term id

Returns

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

clingo_error_bad_alloc

◆ clingo_backend_theory_term_string()

CLINGO_VISIBILITY_DEFAULT bool clingo_backend_theory_term_string	(	clingo_backend_t *	backend,
		char const *	string,
		clingo_id_t *	term_id
	)

Add a theory term representing a string.

Parameters

[in]	backend	the target backend
[in]	string	the value of the term
[out]	term_id	the resulting term id

Returns

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

clingo_error_bad_alloc

◆ clingo_backend_theory_term_symbol()

CLINGO_VISIBILITY_DEFAULT bool clingo_backend_theory_term_symbol	(	clingo_backend_t *	backend,
		clingo_symbol_t	symbol,
		clingo_id_t *	term_id
	)

Convert the given symbol into a theory term.

Parameters

[in]	backend	the target backend
[in]	symbol	the symbol to convert
[out]	term_id	the resulting term id

Returns

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

clingo_error_bad_alloc

◆ clingo_backend_weight_rule()

CLINGO_VISIBILITY_DEFAULT bool clingo_backend_weight_rule	(	clingo_backend_t *	backend,
		bool	choice,
		clingo_atom_t const *	head,
		size_t	head_size,
		clingo_weight_t	lower_bound,
		clingo_weighted_literal_t const *	body,
		size_t	body_size
	)

Add a weight rule to the program.

Attention: All weights and the lower bound must be positive.

Parameters

[in]	backend	the target backend
[in]	choice	determines if the head is a choice or a disjunction
[in]	head	the head atoms
[in]	head_size	the number of atoms in the head
[in]	lower_bound	the lower bound of the weight rule
[in]	body	the weighted body literals
[in]	body_size	the number of weighted literals in the body

Returns

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

clingo_error_bad_alloc

Detailed Description

Typedefs

Enumerations

Functions

Enumeration Type Documentation

◆ clingo_theory_sequence_type_e

Function Documentation

◆ clingo_backend_acyc_edge()

◆ clingo_backend_add_atom()

◆ clingo_backend_assume()

◆ clingo_backend_begin()

◆ clingo_backend_end()

◆ clingo_backend_external()

◆ clingo_backend_heuristic()

◆ clingo_backend_minimize()

◆ clingo_backend_project()

◆ clingo_backend_rule()

◆ clingo_backend_theory_atom()

◆ clingo_backend_theory_atom_with_guard()

◆ clingo_backend_theory_element()

◆ clingo_backend_theory_term_function()

◆ clingo_backend_theory_term_number()

◆ clingo_backend_theory_term_sequence()

◆ clingo_backend_theory_term_string()

◆ clingo_backend_theory_term_symbol()

◆ clingo_backend_weight_rule()