java_cup

Class symbol_set

java.lang.Object

java_cup.symbol_set

public class symbol_set
extends Object

This class represents a set of symbols and provides a series of set operations to manipulate them.

Version:

last updated: 11/25/95

Author:

Scott Hudson

See Also:

symbol

Field Summary

Fields

Modifier and Type	Field and Description
protected Hashtable<String,symbol>	_all A hash table to hold the set.

Constructor Summary

Constructors

Constructor and Description
symbol_set() Constructor for an empty set.
symbol_set(symbol_set other) Constructor for cloning from another set.

Method Summary

Modifier and Type	Method and Description
boolean	add(symbol_set other) Add (union) in a complete set.
boolean	add(symbol sym) Add a single symbol to the set.
Enumeration<symbol>	all() Access to all elements of the set.
boolean	contains(symbol sym) Determine if the set contains a particular symbol.
boolean	equals(Object other) Generic equality comparison.
boolean	equals(symbol_set other) Equality comparison.
int	hashCode() Compute a hash code.
boolean	is_subset_of(symbol_set other) Determine if this set is an (improper) subset of another.
boolean	is_superset_of(symbol_set other) Determine if this set is an (improper) superset of another.
protected void	not_null(Object obj) Helper function to test for a null object and throw an exception if one is found.
void	remove(symbol_set other) Remove (set subtract) a complete set.
void	remove(symbol sym) Remove a single symbol if it is in the set.
int	size() size of the set
String	toString() Convert to a string.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

_all

protected Hashtable<String,symbol> _all

A hash table to hold the set. Symbols are keyed using their name string.

Constructor Detail

symbol_set

public symbol_set()

Constructor for an empty set.

symbol_set

public symbol_set(symbol_set other)
           throws internal_error

Constructor for cloning from another set.

Parameters:

other - the set we are cloning from.

Throws:

internal_error

Method Detail

all

public Enumeration<symbol> all()

Access to all elements of the set.

size

public int size()

size of the set

not_null

protected void not_null(Object obj)
                 throws internal_error

Helper function to test for a null object and throw an exception if one is found.

Parameters:

obj - the object we are testing.

Throws:

internal_error

contains

public boolean contains(symbol sym)

Determine if the set contains a particular symbol.

Parameters:

sym - the symbol we are looking for.

is_subset_of

public boolean is_subset_of(symbol_set other)
                     throws internal_error

Determine if this set is an (improper) subset of another.

Parameters:

other - the set we are testing against.

Throws:

internal_error

is_superset_of

public boolean is_superset_of(symbol_set other)
                       throws internal_error

Determine if this set is an (improper) superset of another.

Parameters:

other - the set we are are testing against.

Throws:

internal_error

add

public boolean add(symbol sym)
            throws internal_error

Add a single symbol to the set.

Parameters:

sym - the symbol we are adding.

Returns:

true if this changes the set.

Throws:

internal_error

remove

public void remove(symbol sym)
            throws internal_error

Remove a single symbol if it is in the set.

Parameters:

sym - the symbol we are removing.

Throws:

internal_error

add

public boolean add(symbol_set other)
            throws internal_error

Add (union) in a complete set.

Parameters:

other - the set we are adding in.

Returns:

true if this changes the set.

Throws:

internal_error

remove

public void remove(symbol_set other)
            throws internal_error

Remove (set subtract) a complete set.

Parameters:

other - the set we are removing.

Throws:

internal_error

equals

public boolean equals(symbol_set other)

Equality comparison.

equals

public boolean equals(Object other)

Generic equality comparison.

Overrides:

equals in class Object

hashCode

public int hashCode()

Compute a hash code.

Overrides:

hashCode in class Object

toString

public String toString()

Convert to a string.

Overrides:

toString in class Object