Package net.sf.saxon.regex

Class EmptyString

java.lang.Object

net.sf.saxon.regex.UnicodeString

net.sf.saxon.regex.EmptyString

All Implemented Interfaces:

java.lang.CharSequence, java.lang.Comparable<UnicodeString>, AtomicMatchKey

public final class EmptyString
extends UnicodeString

An implementation of UnicodeString representing a zero-length string. This is a singleton class with only one instance.

Field Summary

Fields

Modifier and Type	Field	Description
static EmptyString	THE_INSTANCE

Fields inherited from interface net.sf.saxon.expr.sort.AtomicMatchKey

NaN_MATCH_KEY

Method Summary

Modifier and Type	Method	Description
char	charAt(int index)
boolean	isEnd(int pos)	Ask whether a given position is at (or beyond) the end of the string
int	length()
java.lang.CharSequence	subSequence(int start, int end)
java.lang.String	toString()
int	uCharAt(int pos)	Get the character at a specified position
int	uIndexOf(int search, int pos)	Get the first match for a given character
int	uLength()	Get the length of the string, in Unicode codepoints
EmptyString	uSubstring(int beginIndex, int endIndex)	Get a substring of this string

Methods inherited from class net.sf.saxon.regex.UnicodeString

asAtomic, compareTo, containsSurrogatePairs, equals, hashCode, makeUnicodeString, makeUnicodeString

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.CharSequence

chars, codePoints

Field Detail

THE_INSTANCE

public static final EmptyString THE_INSTANCE

Method Detail

uSubstring

public EmptyString uSubstring(int beginIndex,
                              int endIndex)

Description copied from class: UnicodeString

Get a substring of this string

Specified by:

uSubstring in class UnicodeString

Parameters:

beginIndex - the index of the first character to be included (counting codepoints, not 16-bit characters)

endIndex - the index of the first character to be NOT included (counting codepoints, not 16-bit characters)

Returns:

a substring

uCharAt

public int uCharAt(int pos)

Description copied from class: UnicodeString

Get the character at a specified position

Specified by:

uCharAt in class UnicodeString

Parameters:

pos - the index of the required character (counting codepoints, not 16-bit characters)

Returns:

a character (Unicode codepoint) at the specified position.

uIndexOf

public int uIndexOf(int search,
                    int pos)

Description copied from class: UnicodeString

Get the first match for a given character

Specified by:

uIndexOf in class UnicodeString

Parameters:

search - the character to look for

pos - the first position to look

Returns:

the position of the first occurrence of the sought character, or -1 if not found

uLength

public int uLength()

Description copied from class: UnicodeString

Get the length of the string, in Unicode codepoints

Specified by:

uLength in class UnicodeString

Returns:

the number of codepoints in the string

isEnd

public boolean isEnd(int pos)

Description copied from class: UnicodeString

Ask whether a given position is at (or beyond) the end of the string

Specified by:

isEnd in class UnicodeString

Parameters:

pos - the index of the required character (counting codepoints, not 16-bit characters)

Returns:

true iff if the specified index is after the end of the character stream

toString

public java.lang.String toString()

Specified by:

toString in interface java.lang.CharSequence

Overrides:

toString in class java.lang.Object

length

public int length()

charAt

public char charAt(int index)

subSequence

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