awali::dyn::automaton_t Class Reference

An automaton_t is essentially a shared pointer to an abstract_automaton_t, but also contains static functions serving as constructors. More...

#include <automaton.hh>

Inheritance diagram for awali::dyn::automaton_t:

Data Structures
struct	with_int_labels
	Helper class that contains convenience constructor for automata with int labels. More...

Public Member Functions
	automaton_t ()
	Buils an automaton_t that is essentially a nullptr; should generally not be used. More...
template<class T >
	automaton_t (const std::shared_ptr< T > &ptr, typename std::enable_if< std::is_base_of< abstract_automaton_t, T >::value, int >::type=0)
	Builds a automaton from a shared pointer to a class derived of abstract_automaton_t; should generally not be used. More...
	automaton_t (context::labelset_description ld, context::weightset_description wd)
	Builds a new empty automaton whose labelset is described by ld and weightset by wd. More...

Static Public Member Functions
static automaton_t	from (std::string alphabet, bool allow_eps_transitions, std::string="B")
	Builds a boolean automaton over given alphabet, that possibly allows eps_transitions. More...
static automaton_t	from (std::string alphabet, std::string weightset="B", bool allow_eps_transitions=false)
	Builds an automaton with labels in given alphabet possibly allowing epsilon transitions, and with weights in given weightset. More...
static automaton_t	from_context (context_t ctx)
	Builds a new automaton whose labelset and weightset are given by ctx. More...

Detailed Description

An automaton_t is essentially a shared pointer to an abstract_automaton_t, but also contains static functions serving as constructors.

See the documentation of abstract_automaton_t for help on the methods on automata.

Example (Building an automaton)

automaton_t aut = automaton_t::from("ab"); // Builds an empty automaton over the alphabet
 
state_t s = aut->add_state(); // adding two states
state_t t = aut->add_state();
 
aut->set_initial(s);  // making state `s` initial
aut->set_final(t);    //making state `t` final
 
aut->set_transition(s,s,'b'); // A loop labelled by 'b' on both states
aut->set_transition(t,t,'b');
 
aut->set_transition(s,t,'a'); // Reading an 'a' changes the states
aut->set_transition(t,s,'a');
 
//aut now recognizes the words over {a,b} with an odd number of 'a's.
 
pdfdisplay(aut); // Outputs `aut` to a temporary file as a pdf image
                 // and opens it with the default pdf viewer.

Example (Building an automaton from an expression)

ratexp_t exp = ratexp_t::from("(a+b)*bb(a+b)*");
automaton_t aut1 = exp_to_aut(exp);
aut1 = minimal_automaton(aut1); // determinizes and minimizes `aut`
 
// The same result may be obtained directly from the expression.
automaton_t aut2 = minimal_automaton(exp);
 
std::cout << are_isomorphic(aut1,aut2) << std::endl; // outputs 1

Example (Building a weighted automaton)

// Builds an automaton with transitions labelled in {a,b} and weighted in Z.
automaton_t aut = automaton_t::from("ab","Z", false);
 
state_t s = aut->add_state();
state_t t = aut->add_state();
 
aut->set_initial(s, 1); // Set initial weight of `s` to 1
aut->set_final(t, 1); // Set final weight of `t` to 1
 
aut->set_transition(s,s,'a',1);
aut->set_transition(s,s,'b',1);
aut->set_transition(t,t,'a',1);
aut->set_transition(t,t,'b',1);
aut->set_transition(s,t,'b',1);
 
// `aut` is an automaton that associate with every word the number of b' in it.
int i = (int) eval(aut,"bbbaaabbaaab"); // `i` equals 6
 
save(aut,"count-b.json"); // Saves `aut` in JSON format to file "count-b.json"

See also group Factories.

Constructor & Destructor Documentation

automaton_t() [1/2]

awali::dyn::automaton_t::automaton_t

(

)

Buils an automaton_t that is essentially a nullptr; should generally not be used.

automaton_t() [2/2]

template<class T >

awali::dyn::automaton_t::automaton_t	(	const std::shared_ptr< T > &	ptr,
		typename std::enable_if< std::is_base_of< abstract_automaton_t, T >::value, int >::type	= 0
	)

Builds a automaton from a shared pointer to a class derived of abstract_automaton_t; should generally not be used.

Both ptr and the built automaton_t will share ownership of pointed object.

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

• /home/marsault/git-client/telecom/awali.git/awali/dyn/core/automaton.hh