structure
Class CharSet

java.lang.Object
  |
  +--structure.CharSet

public class CharSet

extends Object

Implementation of a set of characters whose ASCII values are between 0 and 255, inclusive. This set is specialized for use with characters. It is implemented using the BitSet class. This class's interface differs from the Set, java.util.Bitset, and Set interfaces, so care must be taken to invoke the proper methods.

See Also:

BitSet, java.util.BitSet

Field Summary

protected BitSet

s

Constructor Summary

CharSet()
Constructs an empty charset.

Method Summary

void	add(char c) Adds character c to set if not already there.
void	clear() Removes the characters of the set.
Object	clone() Construct a duplicate of the character set.
boolean	contains(char c) Detects whether c is a member of this set.
Object	difference(CharSet other) Computes the difference between this and other charset.
boolean	equals(Object other) Detect if two sets are equal.
Object	intersection(CharSet other) Computes the intersection of this charset and other.
boolean	isEmpty() Detect an empty charset.
void	remove(char c) Removes a character from set.
boolean	subset(CharSet other) Detects if this set within the other.
String	toString() Compute String representation of charset.
Object	union(CharSet other) Constructs a charset that is the union of this and other.

Methods inherited from class java.lang.Object

, finalize, getClass, hashCode, notify, notifyAll, registerNatives, wait, wait, wait

Field Detail

s

protected BitSet s

Constructor Detail

CharSet

public CharSet()

Constructs an empty charset.

Method Detail

add

public void add(char c)

Adds character c to set if not already there.

Parameters:

c - The character to be added to set.

Postcondition:

adds c to set

remove

public void remove(char c)

Removes a character from set. Does nothing if char not in set.

Parameters:

c - The character to be removed.

Postcondition:

removes c from set, if present

contains

public boolean contains(char c)

Detects whether c is a member of this set.

Parameters:

c - The char sought.

Postcondition:

returns true iff c in set

Returns:

True iff c is a member of this set.

clear

public void clear()

Removes the characters of the set.

Postcondition:

removes all characters from set

clone

public Object clone()

Construct a duplicate of the character set.

Overrides:

clone in class Object

Postcondition:

constructs a copy of this set

Returns:

Returns a duplicate of this character set.

union

public Object union(CharSet other)

Constructs a charset that is the union of this and other.

Parameters:

other - The other character set.

Precondition:

other is not null

Postcondition:

returns new set with characters from this or other

Returns:

The result of the union --- contains c if in either set.

intersection

public Object intersection(CharSet other)

Computes the intersection of this charset and other.

Parameters:

other - The other character set.

Precondition:

other is not null

Postcondition:

returns new set with characters from this and other

Returns:

The intersection of this and other --- char in result if in both.

difference

public Object difference(CharSet other)

Computes the difference between this and other charset.

Parameters:

other - The other character set.

Precondition:

other is not null

Postcondition:

returns new set with characters from this but not other

Returns:

the result of difference --- chars in this but not other.

subset

public boolean subset(CharSet other)

Detects if this set within the other.

Parameters:

other - The potential superset.

Precondition:

other is not null

Postcondition:

returns true if this is a subset of other

isEmpty

public boolean isEmpty()

Detect an empty charset.

Postcondition:

returns true iff set is empty

Returns:

True if this charset is empty.

equals

public boolean equals(Object other)

Detect if two sets are equal.

Overrides:

equals in class Object

Parameters:

other - The other set.

Precondition:

other is not null

Postcondition:

returns true if this contains same values as other

Returns:

True if this set and other set are identical.

toString

public String toString()

Compute String representation of charset.

Overrides:

toString in class Object

Postcondition:

returns string representation of set

Returns:

String representing this charset.