ired::Assignment Class Reference

A (partial) assignment of variables to values. More...

#include <assignment.hpp>

Public Types
using	assignment_t = Assignment
	assignment type
using	var_idx_t = int
	variable index type
using	var_value_t = int
	variable value type

Public Member Functions
	Assignment (const FiniteDomainVector &domains)
	construct empty
const auto &	operator[] (var_idx_t i) const
	get value of a variable (read only)
auto &	operator[] (var_idx_t i)
	get value of a variable (read/write)
const auto &	values () const
	get values (read only)
auto	size () const
	get number of variables in assignment
auto	is_det (var_idx_t i) const
	check whether variable is determined
void	set_undet (var_idx_t i)
	set variables to undetermined
void	set_undet (const std::vector< var_idx_t > &xs)
	set variables to undetermined
void	inc (var_idx_t i)
	increment value of variable
template<class FeatureNetwork >
auto	make_iterator (const std::vector< var_idx_t > &vars, const FeatureNetwork &cn, const std::vector< const typename FeatureNetwork::constraint_t * > &constraints, const std::vector< const typename FeatureNetwork::function_t * > &functions, const typename FeatureNetwork::fun_value_t &initial_value)
	make sub-assignment iterator
template<class Function , class EP >
auto	eval_determined (const std::vector< const Function * > &functions, const EP &)
	evaluate constraints/functions where all variables are already determined
template<class CN >
auto	make_iterator (const std::vector< var_idx_t > &vars, const CN &cn, const std::vector< const typename CN::constraint_t * > &constraints, const std::vector< const typename CN::function_t * > &functions, const typename CN::fun_value_t &initial_value)

Detailed Description

A (partial) assignment of variables to values.

An object of Assignment associates values to a series of /finite domain/ variables (indexed 0..n-1); typically the variables belong to a constraint network CN (

See also

FeatureNetwork).

In an assignment for the CN, variables are associated to values in their finite integer domain (according to CN) or are undetermined (encoded domain specifically!). Assignments are total, if no variable is undetermined.

Partial assignments can be enumerated using objects of class AssignmentIterator. Such iterators are generated for an assignment using make_iterator; typically they are used to iterate over a subset of the variables in the CN while evaluating functions and checking constraints.

An assignment is valid for a set of constraints, iff all the constraints are satisfied (evaluate to true). The value of an assignment for a set of functions is the product (as defined by the EvaluationPolicy) of the function values for the assignment. Only assignments with non-zero (zero def'd by EvaluationPolicy) evaluation are valid for the functions.

Member Typedef Documentation

assignment_t

using ired::Assignment::assignment_t = Assignment

assignment type

var_idx_t

using ired::Assignment::var_idx_t = int

variable index type

var_value_t

using ired::Assignment::var_value_t = int

variable value type

Constructor & Destructor Documentation

Assignment()

ired::Assignment::Assignment ( const FiniteDomainVector &  domains )

inlineexplicit

construct empty

Parameters

domains

domains of the variables; attention: domains must stay available

after construction, all variables are undetermined

Member Function Documentation

eval_determined()

template<class Function , class EP >

auto ired::Assignment::eval_determined ( const std::vector< const Function * > &  functions, const EP &    )

inline

evaluate constraints/functions where all variables are already determined

Returns

product of determined function values

inc()

void ired::Assignment::inc ( var_idx_t  i )

inline

increment value of variable

Parameters

i	index of variable

is_det()

auto ired::Assignment::is_det ( var_idx_t  i ) const

inline

check whether variable is determined

Parameters

i	variable index

make_iterator() [1/2]

template<class CN >

auto ired::Assignment::make_iterator	(	const std::vector< var_idx_t > &	vars,
		const CN &	cn,
		const std::vector< const typename CN::constraint_t * > &	constraints,
		const std::vector< const typename CN::function_t * > &	functions,
		const typename CN::fun_value_t &	initial_value
	)

make_iterator() [2/2]

template<class FeatureNetwork >

auto ired::Assignment::make_iterator	(	const std::vector< var_idx_t > &	vars,
		const FeatureNetwork &	cn,
		const std::vector< const typename FeatureNetwork::constraint_t * > &	constraints,
		const std::vector< const typename FeatureNetwork::function_t * > &	functions,
		const typename FeatureNetwork::fun_value_t &	initial_value
	)

make sub-assignment iterator

See also

class AssignmentIterator

Parameters

vars	vector of indices of the to-be-enumerated variables
cn	constraint network, where everything takes place
constraints	check assignments
functions	check and evaluate assignments

operator[]() [1/2]

auto & ired::Assignment::operator[] ( var_idx_t  i )

inline

get value of a variable (read/write)

Parameters

i	variable index

Returns

value of variable i

operator[]() [2/2]

const auto & ired::Assignment::operator[] ( var_idx_t  i ) const

inline

get value of a variable (read only)

Parameters

i	variable index

Returns

value of variable i

set_undet() [1/2]

void ired::Assignment::set_undet ( const std::vector< var_idx_t > &  xs )

inline

set variables to undetermined

Parameters

xs	vector of variable indices

set_undet() [2/2]

void ired::Assignment::set_undet ( var_idx_t  i )

inline

set variables to undetermined

Parameters

i	index of variable

size()

auto ired::Assignment::size ( ) const

inline

get number of variables in assignment

values()

const auto & ired::Assignment::values ( ) const

inline

get values (read only)

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The documentation for this class was generated from the following file:

• src/infrared/assignment.hpp