net.sf.saxon.str

Class StringTool

java.lang.Object

net.sf.saxon.str.StringTool

public class StringTool
extends java.lang.Object

Constructor Summary

Constructors

Constructor and Description
StringTool()

Method Summary

Modifier and Type	Method and Description
static void	appendRepeated(java.lang.StringBuilder builder, char ch, int count) Insert repeated occurrences of a given character at the end of a StringBuilder
static IntIterator	codePoints(java.lang.CharSequence value)
static UnicodeString	compress(char[] in, int offset, int len, boolean compressWS) Attempt to compress a UnicodeString consisting entirely of whitespace.
static boolean	containsSurrogates(java.lang.String str) Ask whether a string contains astral characters (represented as surrogate pairs)
static void	copy16to24(char[] source, int sourcePos, byte[] dest, int destPos, int count) Copy from an array of 16-bit characters to an array holding 16-bit characters.
static void	copy8to16(byte[] source, int sourcePos, char[] dest, int destPos, int count) Copy from an array of 8-bit characters to an array holding 16-bit characters.
static void	copy8to24(byte[] source, int sourcePos, byte[] dest, int destPos, int count) Copy from an array of 8-bit characters to an array holding 24-bit characters, organised as three bytes per character The caller is responsible for ensuring that the offsets are in range and that the destination array is large enough.
static java.lang.String	diagnosticDisplay(java.lang.String s) Produce a diagnostic representation of the contents of the string
static int[]	expand(UnicodeString s) Expand a string into an array of 32-bit characters
static UnicodeString	fromCharSequence(java.lang.CharSequence chars)
static UnicodeString	fromCodePoints(int[] codes, int used) Contract an array of integers containing Unicode codepoints into a string
static UnicodeString	fromLatin1(java.lang.String str)
static int	getStringLength(java.lang.CharSequence s) Get the length of a string, as defined in XPath.
static int	lastCodePoint(UnicodeString str) Get the last codepoint in a UnicodeString
static long	lastIndexOf(UnicodeString str, int codePoint) Get the position of the last occurrence of a given codepoint within a string
static void	prependRepeated(java.lang.StringBuilder builder, char ch, int count) Insert repeated occurrences of a given character at the start of a StringBuilder
static void	prependWideChar(java.lang.StringBuilder builder, int ch) Insert a wide character (surrogate pair) at the start of a StringBuilder
static int	requireInt(long value) Utility method for use where strings longer than 2^31 characters cannot yet be handled.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

StringTool

public StringTool()

Method Detail

getStringLength

public static int getStringLength(java.lang.CharSequence s)

Get the length of a string, as defined in XPath. This is not the same as the Java length, as a Unicode surrogate pair counts as a single character.

Parameters:

s - The string whose length is required

Returns:

the length of the string in Unicode code points

expand

public static int[] expand(UnicodeString s)

Expand a string into an array of 32-bit characters

Parameters:

s - the string to be expanded

Returns:

an array of integers representing the Unicode code points

containsSurrogates

public static boolean containsSurrogates(java.lang.String str)

Ask whether a string contains astral characters (represented as surrogate pairs)

Parameters:

str - the string to be tested

Returns:

true if the string contains surrogate characters

fromCodePoints

public static UnicodeString fromCodePoints(int[] codes,
                                           int used)

Contract an array of integers containing Unicode codepoints into a string

Parameters:

codes - an array of integers representing the Unicode code points

used - the number of items in the array that are actually used

Returns:

the constructed string

fromCharSequence

public static UnicodeString fromCharSequence(java.lang.CharSequence chars)

fromLatin1

public static UnicodeString fromLatin1(java.lang.String str)

codePoints

public static IntIterator codePoints(java.lang.CharSequence value)

diagnosticDisplay

public static java.lang.String diagnosticDisplay(java.lang.String s)

Produce a diagnostic representation of the contents of the string

Parameters:

s - the string

Returns:

a string in which non-Ascii-printable characters are replaced by \ uXXXX escapes

prependWideChar

public static void prependWideChar(java.lang.StringBuilder builder,
                                   int ch)

Insert a wide character (surrogate pair) at the start of a StringBuilder

Parameters:

builder - the string builder

ch - the codepoint of the character to be inserted

prependRepeated

public static void prependRepeated(java.lang.StringBuilder builder,
                                   char ch,
                                   int count)

Insert repeated occurrences of a given character at the start of a StringBuilder

Parameters:

builder - the string builder

ch - the character to be inserted

count - the number of repetitions

appendRepeated

public static void appendRepeated(java.lang.StringBuilder builder,
                                  char ch,
                                  int count)

Insert repeated occurrences of a given character at the end of a StringBuilder

Parameters:

builder - the string builder

ch - the character to be inserted

count - the number of repetitions

lastCodePoint

public static int lastCodePoint(UnicodeString str)

Get the last codepoint in a UnicodeString

Parameters:

str - the input string

Returns:

the integer value of the last character in the string

Throws:

java.lang.IndexOutOfBoundsException - if the string is empty

lastIndexOf

public static long lastIndexOf(UnicodeString str,
                               int codePoint)

Get the position of the last occurrence of a given codepoint within a string

Parameters:

str - the input string

codePoint - the sought codepoint

Returns:

the zero-based position of the last occurrence of the codepoint within the input string, or -1 if the codepoint does not appear within the string

requireInt

public static int requireInt(long value)

Utility method for use where strings longer than 2^31 characters cannot yet be handled.

Parameters:

value - the actual value of a character position within a string, or the length of a string

Returns:

the value as an integer if it is within range

Throws:

java.lang.UnsupportedOperationException - if the supplied value exceeds Integer.MAX_VALUE

compress

public static UnicodeString compress(char[] in,
                                     int offset,
                                     int len,
                                     boolean compressWS)

Attempt to compress a UnicodeString consisting entirely of whitespace. This is the first thing we do to an incoming text node

Parameters:

in - the Unicode string to be compressed

offset - the start position of the substring we are interested in

len - the length of the substring we are interested in

compressWS - set to true if whitespace compression is to be attempted

Returns:

the compressed sequence if it can be compressed; or the uncompressed UnicodeString otherwise

copy8to16

public static void copy8to16(byte[] source,
                             int sourcePos,
                             char[] dest,
                             int destPos,
                             int count)

Copy from an array of 8-bit characters to an array holding 16-bit characters. The caller is responsible for ensuring that the offsets are in range and that the destination array is large enough.

Parameters:

source - the source array

sourcePos - the position in the source array where copying is to start

dest - the destination array

destPos - the position in the destination array where copying is to start

count - the number of characters (codepoints) to copy

copy8to24

public static void copy8to24(byte[] source,
                             int sourcePos,
                             byte[] dest,
                             int destPos,
                             int count)

Copy from an array of 8-bit characters to an array holding 24-bit characters, organised as three bytes per character The caller is responsible for ensuring that the offsets are in range and that the destination array is large enough.

Parameters:

source - the source array

sourcePos - the position in the source array where copying is to start

dest - the destination array, using three bytes per codepoint

destPos - the codepoint position (not byte position) in the destination array where copying is to start

count - the number of characters (codepoints) to copy

copy16to24

public static void copy16to24(char[] source,
                              int sourcePos,
                              byte[] dest,
                              int destPos,
                              int count)

Copy from an array of 16-bit characters to an array holding 16-bit characters. The caller is responsible for ensuring that the offsets are in range and that the destination array is large enough.

Parameters:

source - the source array. The caller is responsible for ensuring that this contains no surrogates

sourcePos - the position in the source array where copying is to start

dest - the destination array

destPos - the position in the destination array where copying is to start

count - the number of characters (codepoints) to copy