org.nineml.coffeegrinder.parser

Class Rule

java.lang.Object

org.nineml.coffeegrinder.parser.Rule

public class Rule
extends java.lang.Object

A grammar rule.

A grammar rule maps a single NonterminalSymbol to zero or more symbols (either Terminals or further Nonterminals).

Field Summary

Fields

Modifier and Type	Field and Description
RightHandSide	rhs
NonterminalSymbol	symbol

Constructor Summary

Constructors

Constructor and Description
Rule(NonterminalSymbol symbol, java.util.List<Symbol> rhs) Construct a new rule mapping the nonterminal to a sequence of symbols.
Rule(NonterminalSymbol symbol, Symbol... rhs) Construct a new rule mapping the nonterminal to a sequence of symbols.

Method Summary

Modifier and Type	Method and Description
boolean	epsilonRule()
boolean	equals(java.lang.Object obj)
RightHandSide	getRhs() The sequence of symbols that comprise the definition of the rule's nonterminal.
java.util.List<State>	getSlots()
NonterminalSymbol	getSymbol() The nonterminal symbol defined by this rule.
int	hashCode()
java.lang.String	toString() Pretty print a node.

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Field Detail

symbol

public final NonterminalSymbol symbol

rhs

public final RightHandSide rhs

Constructor Detail

Rule

public Rule(NonterminalSymbol symbol,
            Symbol... rhs)

Construct a new rule mapping the nonterminal to a sequence of symbols.

If the sequence of symbols is empty or null, then the nonterminal maps to "ε", that is to say, it's allowed to be absent.

Parameters:

symbol - The nonterminal.

rhs - The sequence of symbols.

Rule

public Rule(NonterminalSymbol symbol,
            java.util.List<Symbol> rhs)

Construct a new rule mapping the nonterminal to a sequence of symbols.

If the sequence of symbols is empty or null, then the nonterminal maps to "ε", that is to say, it's allowed to be absent.

Parameters:

symbol - The nonterminal.

rhs - The list of symbols.

Method Detail

getSymbol

public NonterminalSymbol getSymbol()

The nonterminal symbol defined by this rule.

Returns:

The nonterminal symbol.

getRhs

public RightHandSide getRhs()

The sequence of symbols that comprise the definition of the rule's nonterminal.

Note: although a rule may be defined with a null "right hand side", this method always returns an empty list in such cases.

Returns:

The sequence of symbols.

epsilonRule

public boolean epsilonRule()

getSlots

public java.util.List<State> getSlots()

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()

Pretty print a node.

Overrides:

toString in class java.lang.Object

Returns:

a string representation of the node.