javatools.datatypes
Class CompressedString

java.lang.Object
  javatools.datatypes.CompressedString

All Implemented Interfaces:

java.lang.CharSequence, java.lang.Comparable<CompressedString>

public class CompressedString
extends java.lang.Object
implements java.lang.CharSequence, java.lang.Comparable<CompressedString>

This class is part of the Java Tools (see http://mpii.de/yago-naga/javatools). It is licensed under the Creative Commons Attribution License (see http://creativecommons.org/licenses/by/3.0) by the YAGO-NAGA team (see http://mpii.de/yago-naga). This class represents an equivalence class of Strings. The equivalence class stores one prototype String, but compresses the String with 7, 6 or less bits per character (the String-class uses 16). This makes the CompressedString less memory consuming than a normal String, but possibly the original String cannot be reconstructed. The less bits you use, the less space you will consume, the less likely it will be that you can reconstruct the original String and the larger the equivalence class will be. Example:

    System.out.println(new CompressedString("How are you?",7));
    System.out.println(new CompressedString("How are you?",6));
    System.out.println(new CompressedString("How are you?",5));
    System.out.println(new CompressedString("How are you?",4));
    System.out.println(new CompressedString("How are you?",3)); 
    -->
        How are you?
        HOW ARE YOU?
        HOW ARE YOU?
        HOW@ARE@YOU
        HOG@ABE@IOEO










Constructor Summary
CompressedString(java.lang.CharSequence s1)



          Compresses a CharSequence with  6 bits
CompressedString(java.lang.CharSequence s1,
                 int bits)



          Compresses a CharSequence
 



Method Summary




 int
bits()



          Returns the bits per character



 char
charAt(int index)



          Returns the character at position index



 int
compareTo(java.lang.CharSequence s0)



          1 if this CompressedString is lexically larger than the 
 CompressedString of the argument, else -1 or 0



 int
compareTo(CompressedString s)



          1 if this CompressedString is lexically larger than the 
 the argument, else -1 or 0



 boolean
equals(java.lang.Object o)



          Tells whether the argument (any CharSequence) 
 is in the equivalence class of this CompressedString



 int
hashCode()



          Returns a hash-code



 int
length()



          Returns the number of characters in this CompressedString



static void
main(java.lang.String[] args)



          Test routine



 java.lang.CharSequence
normalize(java.lang.CharSequence s)



          Normalizes (see Char.java) and upcases a CharSequence if necessary



 int
size()



          Returns the bytes used by this CompressedString



 java.lang.CharSequence
subSequence(int start,
            int end)



          Returns a subsequence of this CompressedString (without duplicating the data)



 java.lang.String
toString()



          Tries to reconstruct the original String


 
Methods inherited from class java.lang.Object
getClass, notify, notifyAll, wait, wait, wait
 





Constructor Detail



CompressedString
public CompressedString(java.lang.CharSequence s1,
                        int bits)

Compresses a CharSequence





CompressedString
public CompressedString(java.lang.CharSequence s1)

Compresses a CharSequence with  6 bits






Method Detail



hashCode
public int hashCode()

Returns a hash-code


Overrides:
hashCode in class java.lang.Object








length
public int length()

Returns the number of characters in this CompressedString


Specified by:
length in interface java.lang.CharSequence








size
public int size()

Returns the bytes used by this CompressedString











bits
public int bits()

Returns the bits per character











charAt
public char charAt(int index)

Returns the character at position index


Specified by:
charAt in interface java.lang.CharSequence








equals
public boolean equals(java.lang.Object o)

Tells whether the argument (any CharSequence) 
 is in the equivalence class of this CompressedString


Overrides:
equals in class java.lang.Object








normalize
public java.lang.CharSequence normalize(java.lang.CharSequence s)

Normalizes (see Char.java) and upcases a CharSequence if necessary











compareTo
public int compareTo(java.lang.CharSequence s0)

1 if this CompressedString is lexically larger than the 
 CompressedString of the argument, else -1 or 0











compareTo
public int compareTo(CompressedString s)

1 if this CompressedString is lexically larger than the 
 the argument, else -1 or 0


Specified by:
compareTo in interface java.lang.Comparable<CompressedString>








subSequence
public java.lang.CharSequence subSequence(int start,
                                          int end)

Returns a subsequence of this CompressedString (without duplicating the data)


Specified by:
subSequence in interface java.lang.CharSequence








toString
public java.lang.String toString()

Tries to reconstruct the original String


Specified by:
toString in interface java.lang.CharSequence
Overrides:
toString in class java.lang.Object








main
public static void main(java.lang.String[] args)

Test routine