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 Version 2 module.

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

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...

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_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

Functions

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_weight_rule()