org.nineml.coffeegrinder.parser

Class State

java.lang.Object

org.nineml.coffeegrinder.parser.State

public class State
extends java.lang.Object

States (or Earley items) in the chart. FIXME: this API is in flux.

Field Summary

Fields

Modifier and Type	Field and Description
static State	L0
int	position
RightHandSide	rhs
Rule	rule
NonterminalSymbol	symbol

Method Summary

Modifier and Type	Method and Description
State	advance() Get a new state with the position advanced by one
boolean	completed() Are we finished with this symbol?
boolean	equals(java.lang.Object obj)
Descriptor	getDescriptor(int k, int i)
java.util.Set<Symbol>	getFirst(ParserGrammar grammar)
int	getPosition() Get the current position in this state
RightHandSide	getRhs() Get the list of symbols that define this state's nonterminal symbol.
Rule	getRule() Get the rule that originated this state.
NonterminalSymbol	getSymbol() Get the nonterminal associated with this state
int	hashCode()
Symbol	nextSymbol() Get the next symbol
Symbol	prevSymbol()
java.lang.String	toString()

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Field Detail

L0

public static final State L0

rule

public final Rule rule

symbol

public final NonterminalSymbol symbol

position

public final int position

rhs

public final RightHandSide rhs

Method Detail

nextSymbol

public Symbol nextSymbol()

Get the next symbol

If the state has more symbols, return the symbol that occurs after the current position.

Returns:

the next symbol, or null if position is last

prevSymbol

public Symbol prevSymbol()

getDescriptor

public Descriptor getDescriptor(int k,
                                int i)

getSymbol

public NonterminalSymbol getSymbol()

Get the nonterminal associated with this state

Returns:

the symbol

getRule

public Rule getRule()

Get the rule that originated this state.

Returns:

the rule

getRhs

public RightHandSide getRhs()

Get the list of symbols that define this state's nonterminal symbol.

Returns:

the list of symbols on the "right hand side"

getPosition

public int getPosition()

Get the current position in this state

Returns:

the position

advance

public State advance()

Get a new state with the position advanced by one

Returns:

a new state with the position advanced

Throws:

ParseException - if an attempt is made to advance a completed state

completed

public boolean completed()

Are we finished with this symbol?

Returns:

true if the position indicates that we've seen all of the symbols on the "right hand side"

getFirst

public java.util.Set<Symbol> getFirst(ParserGrammar grammar)

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object