de.up.ling.irtg.automata.index

Interface TopDownRuleIndex

All Known Implementing Classes:

MapTopDownIndex

public interface TopDownRuleIndex

Generic interface for a data structure representing a top-down index of the rules of a tree automaton. Such a data structure supports efficient lookup of the rules with a given parent state and possibly a given terminal symbol.

Author:

koller

Method Summary

Modifier and Type	Method and Description
void	add(Rule rule) Adds a rule to the index.
void	foreachRule(int parentState, Consumer<Rule> fn)
Iterable<Rule>	getAllRules()
IntIterable	getLabelsTopDown(int parentState) Retrieves the terminal symbols such that rules for the given parent state exist.
Iterable<Rule>	getRules(int parentState) Retrieves the rules for a given parent state.
Iterable<Rule>	getRules(int labelId, int parentState) Retrieves the rules for a given parent state and terminal symbol.
boolean	useCachedRule(int label, int parent) Checks whether top-down rules for this parent state and label should be looked up in this index.

Method Detail

add

void add(Rule rule)

Adds a rule to the index.

Parameters:

rule -

getRules

Iterable<Rule> getRules(int parentState)

Retrieves the rules for a given parent state. That is, if you pass the state q as the argument to this method, and there is a rule q -> f(q1,...,qn) for any terminal symbol f, then the returned iterable will contain this rule.

Parameters:

parentState -

Returns:

getLabelsTopDown

IntIterable getLabelsTopDown(int parentState)

Retrieves the terminal symbols such that rules for the given parent state exist. That is, if you pass the state q as the argument to this method, and there is a rule q -> f(q1,...,qn) in the automaton, then the returned iterable will contain f.

Parameters:

parentState -

Returns:

getRules

Iterable<Rule> getRules(int labelId,
                        int parentState)

Retrieves the rules for a given parent state and terminal symbol. That is, if you pass the state q and the terminal symbol f, and there is a rule q -> f(q1,...,qn), then the returned iterable will contain that rule.

Parameters:

labelId -

parentState -

Returns:

useCachedRule

boolean useCachedRule(int label,
                      int parent)

Checks whether top-down rules for this parent state and label should be looked up in this index. This is the case if the index was previously told about rules for the parent and label, or told that there are no rules for the parent and label. The method returns true if the index knows about this parent/label combination. Otherwise it returns false, and the automaton should recompute the rules (and add them to the index).

Parameters:

label -

parent -

Returns:

getAllRules

Iterable<Rule> getAllRules()

foreachRule

void foreachRule(int parentState,
                 Consumer<Rule> fn)