org.nineml.coffeegrinder.parser

Class TerminalSymbol

java.lang.Object

org.nineml.coffeegrinder.util.Decoratable

org.nineml.coffeegrinder.parser.Symbol

org.nineml.coffeegrinder.parser.TerminalSymbol

public class TerminalSymbol
extends Symbol

A terminal symbol.

Terminal symbols match some input token(s) literally.

Field Summary

Fields

Modifier and Type	Field and Description
static TerminalSymbol	EOF
static TerminalSymbol	EPSILON

Constructor Summary

Constructors

Constructor and Description
TerminalSymbol(Token token) Make a symbol for the specified token.
TerminalSymbol(Token token, java.util.Collection<ParserAttribute> attributes) Make a symbol for the specified token with the given attributes
TerminalSymbol(Token token, ParserAttribute attribute) Make a symbol for the specified token with a given ParserAttribute.

Method Summary

Modifier and Type	Method and Description
static TerminalSymbol	ch(char terminal) Return a token for a string.
boolean	equals(java.lang.Object obj) Test tokens for equality.
Token	getToken() Get the token associated with this terminal symbol.
int	hashCode() Assure that equal tokens return the same hash code.
boolean	matches(Symbol input) Does this symbol match this other symbol?
boolean	matches(Token input) Does this symbol match the given token?
static TerminalSymbol	regex(java.lang.String regex) Return a token for a string.
static TerminalSymbol	s(java.lang.String terminal) Return a token for a string.
java.lang.String	toString() Pretty print a token.

Methods inherited from class org.nineml.coffeegrinder.util.Decoratable

addAttribute, addAttributes, getAttribute, getAttributes, getAttributesMap, getAttributeValue, hasAttribute

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Field Detail

EPSILON

public static final TerminalSymbol EPSILON

EOF

public static final TerminalSymbol EOF

Constructor Detail

TerminalSymbol

public TerminalSymbol(Token token)

Make a symbol for the specified token.

Parameters:

token - the token

Throws:

java.lang.NullPointerException - if the token is null

TerminalSymbol

public TerminalSymbol(Token token,
                      ParserAttribute attribute)

Make a symbol for the specified token with a given ParserAttribute.

Parameters:

token - the token

attribute - the attribute

Throws:

java.lang.NullPointerException - if either is null

GrammarException - if the attribute attempts to make the symbol optional

TerminalSymbol

public TerminalSymbol(Token token,
                      java.util.Collection<ParserAttribute> attributes)

Make a symbol for the specified token with the given attributes

Parameters:

token - the token

attributes - a collection of attributes

Throws:

java.lang.NullPointerException - if the token is null

GrammarException - if the attributes attempt to make the symbol optional

Method Detail

s

public static TerminalSymbol s(java.lang.String terminal)

Return a token for a string.

This is just a convenience method for a terminal symbol for a TokenString.

Parameters:

terminal - the string

Returns:

the terminal symbol

ch

public static TerminalSymbol ch(char terminal)

Return a token for a string.

This is just a convenience method for a terminal symbol for a TokenCharacter.

Parameters:

terminal - the character

Returns:

the terminal symbol

regex

public static TerminalSymbol regex(java.lang.String regex)

Return a token for a string.

This is just a convenience method for a terminal symbol for a TokenRegex.

Parameters:

regex - the regex

Returns:

the terminal symbol

getToken

public Token getToken()

Get the token associated with this terminal symbol.

Returns:

the token

matches

public boolean matches(Token input)

Does this symbol match the given token?

Specified by:

matches in class Symbol

Parameters:

input - The token.

Returns:

true if it matches

matches

public final boolean matches(Symbol input)

Does this symbol match this other symbol?

No, it does not. No terminal ever matches another symbol.

Specified by:

matches in class Symbol

Parameters:

input - The other symbol.

Returns:

false

equals

public boolean equals(java.lang.Object obj)

Test tokens for equality.

Two tokens are equal if they represent the same string and have the same attributes.

Overrides:

equals in class java.lang.Object

Parameters:

obj - An object.

Returns:

true if obj is equal to this terminal character.

hashCode

public int hashCode()

Assure that equal tokens return the same hash code.

Overrides:

hashCode in class java.lang.Object

Returns:

the hash code.

toString

public java.lang.String toString()

Pretty print a token.

Overrides:

toString in class java.lang.Object

Returns:

a string representation of the object.