A structure for selecting a set of automaton properties to copy. More...

#include <spot/twa/twa.hh>

Collaboration diagram for spot::twa::prop_set:

Public Member Functions
	prop_set (bool state_based, bool inherently_weak, bool deterministic, bool improve_det, bool complete, bool stutter_inv)

	prop_set (bool state_based, bool inherently_weak, bool deterministic, bool improve_det, bool stutter_inv)

Static Public Member Functions
static prop_set	all ()
	An all-true `prop_set`.

Public Attributes
bool	state_based
	preserve state-based acceptance

bool	inherently_weak
	preserve inherently weak, weak, & terminal

bool	deterministic
	preserve deterministic, semi-det, unambiguous

bool	improve_det
	improve deterministic, semi-det, unambiguous

bool	complete
	preserve completeness

bool	stutter_inv
	preserve stutter invariance

Detailed Description

A structure for selecting a set of automaton properties to copy.

When an algorithm copies an automaton before making some modification on that automaton, it should use a prop_set structure to indicate which properties should be copied from the original automaton.

This structure does not list all supported properties, because properties are copied by groups of related properties. For instance if an algorithm breaks the "inherent_weak" properties, it usually also breaks the "weak" and "terminal" properties.

Set the flags to true to copy the value of the original property, and to false to ignore the original property (leaving the property of the new automaton to its default value, which is trival::maybe()).

This can be used for instance as:

aut->prop_copy(other_aut, {true, false, false, false, false, true});

This would copy the "state-based acceptance" and "stutter invariant" properties from other_aut to aut.

There are two flags for the determinism. If deterministic is set, the universal, semi-deterministic, and unambiguous properties are copied as-is. If deterministic is unset but improve_det is set, then those properties are only copied if they are positive.

The reason there is no default value for these flags is that whenever we add a new property that does not fall into any of these groups, we will be forced to review all algorithms to decide if the property should be preserved or not.

See also: make_twa_graph_ptr; prop_copy

Member Function Documentation

◆ all()

static prop_set spot::twa::prop_set::all ( )

inlinestatic

An all-true prop_set.

Use that only in algorithms that copy an automaton without performing any modification.

If an algorithm X does modifications, but preserves all the properties currently implemented, use an explicit

{true, true, true, true, true, true}

instead of calling all(). This way, the day a new property is added, we will still be forced to review algorithm X, in case that new property is not preserved.