Package eu.bandm.tools.lexic

Class ZAutomaton<V>

java.lang.Object

eu.bandm.tools.lexic.Behavior<List<V>,ZAutomaton<V>>

eu.bandm.tools.lexic.ZAutomaton<V>

Type Parameters:

V - the label value type

All Implemented Interfaces:

FormatClient, Traceable<List<V>>, Traversable<List<V>,ZAutomaton<V>>, Serializable

@PropertyDependency("eu.bandm.tools.lexic.ZAutomaton.asciiCache")
public class ZAutomaton<V>
extends Behavior<List<V>,ZAutomaton<V>>
implements Traceable<List<V>>, Traversable<List<V>,ZAutomaton<V>>

Zero-overhead automaton that is identical to the behavior of its own initial state.

The recommended way to construct a zero-overhead automaton is from a deterministic automaton using DAutomaton.deflate(). Manual construction with prototype(Behavior) and hardPatch(Map) is low-level and error-prone.

The caching of ASCII code points in a direct lookup table is a recommended optimization. It is controlled by the system property ASCII_CACHE_PROPERTY_NAME, which can take values "true" (default) or "false".

See Also:

• DAutomaton
• Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
final class	ZAutomaton.Trace	Iterator-like mutable API for tracking the consumption of an input sequence of code points by an automaton.

Field Summary

Fields

Modifier and Type	Field	Description
(package private) static boolean	ASCII_CACHE	The flag to control ASCII caching.
static final String	ASCII_CACHE_PROPERTY_NAME	The name of the boolean-valued property to control ASCII caching.

Fields inherited from class eu.bandm.tools.lexic.Behavior

label, transitions

Method Summary

Modifier and Type	Method	Description
Behavior<List<V>,ZAutomaton<V>>	getBehavior(ZAutomaton<V> state)	Returns the automaton behavior the given state node.
ZAutomaton<V>	getInitialState()	Returns the initial state node of the transition graph.
(package private) void	hardPatch(Map<?,? extends Behavior<List<V>,?>> substitution)	Changes the transitions of this automaton according to a given substitution.
(package private) static <V> ZAutomaton<V>	prototype(Behavior<List<V>,?> beh)	Creates a prototype automaton from a symbolic behavior.
String	toString()	Returns a human-readable representation of this behavior.
ZAutomaton<V>.Trace	trace()	Returns a fresh trace.

Methods inherited from class eu.bandm.tools.lexic.Behavior

allKeysMatch, anyTransition, constant, consume, consumeAnyOf, consumeAnyOf, consumeAnyOfRange, consumeAnyOfRange, consumeExcept, countTransitions, forEachKey, forEachTransition, forEachTransition, format, format, getDefaultTransition, getLabel, getTransition, intersect, map, mapTransitions, merge, of, simplify, totalize, transitions, translate

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Details

ASCII_CACHE_PROPERTY_NAME

public static final String ASCII_CACHE_PROPERTY_NAME

The name of the boolean-valued property to control ASCII caching.

See Also:

• Constant Field Values

ASCII_CACHE

static boolean ASCII_CACHE

The flag to control ASCII caching.

Method Details

prototype

static <V> ZAutomaton<V> prototype(Behavior<List<V>,?> beh)

Creates a prototype automaton from a symbolic behavior.

This construction exploits type erasure on the JVM; the transitions of the resulting automaton are ill-typed, and latent causes for ClassCastException may arise if it is used without correction. A call to method hardPatch(java.util.Map<?, ? extends eu.bandm.tools.lexic.Behavior<java.util.List<V>, ?>>) should substitute references of type ZAutomaton for all transitions before attempting to use the automaton.

Type Parameters:

V - the value type

Parameters:

beh - the symbolic behavior to emulate

Returns:

a prototype automaton

See Also:

• hardPatch(java.util.Map<?, ? extends eu.bandm.tools.lexic.Behavior<java.util.List<V>, ?>>)

hardPatch

void hardPatch(Map<?,? extends Behavior<List<V>,?>> substitution)

Changes the transitions of this automaton according to a given substitution.

The type of the substituted values is not checked either at compile time or at execution time. Latent causes for ClassCastException may arise if this method is used carelessly.

Parameters:

substitution - the substitution to apply; values not present as keys are left unchanged

See Also:

• prototype(eu.bandm.tools.lexic.Behavior<java.util.List<V>, ?>)

trace

public ZAutomaton<V>.Trace trace()

Returns a fresh trace.

Objects obtained as return values from multiple calls to this method do not share mutable state with each other, and can be used safely in concurrency.

Specified by:

trace in interface Traceable<V>

Returns:

a fresh trace

toString

public String toString()

Description copied from class: Behavior

Returns a human-readable representation of this behavior.

Overrides:

toString in class Behavior<List<V>,ZAutomaton<V>>

getInitialState

public ZAutomaton<V> getInitialState()

Returns the initial state node of the transition graph.

Specified by:

getInitialState in interface Traversable<List<V>,ZAutomaton<V>>

Returns:

the initial state node of the transition graph

getBehavior

public Behavior<List<V>,ZAutomaton<V>> getBehavior(ZAutomaton<V> state)

Returns the automaton behavior the given state node.

The behavior specifies the label attached to the state node, as well as the outgoing transition edges.

Specified by:

getBehavior in interface Traversable<List<V>,ZAutomaton<V>>

Parameters:

state - a state node

Returns:

the automaton behavior at the given state