net.sf.saxon.str

Class Twine24

java.lang.Object

net.sf.saxon.str.UnicodeString

net.sf.saxon.str.Twine24

All Implemented Interfaces:

java.lang.Comparable<UnicodeString>, AtomicMatchKey

public class Twine24
extends UnicodeString

Twine24 is Unicode string that accommodates any codepoint value up to 24 bits. It never includes any surrogates. The length of the string is limited to 2^31-1 codepoints.

Field Summary

Fields

Modifier and Type	Field and Description
protected byte[]	bytes
protected int	cachedHash

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Twine24(byte[] bytes) Protected constructor
	Twine24(int[] codePoints) Construct a Twine from an array of codepoints.
	Twine24(int[] codePoints, int used) Construct a Twine from an array of codepoints.

Method Summary

Modifier and Type	Method and Description
int	codePointAt(long index) Get the code point at a given position in the string
IntIterator	codePoints() Get an iterator over the Unicode codepoints in the value.
int	compareTo(UnicodeString other) Compare this string to another using codepoint comparison
java.lang.String	details()
boolean	equals(java.lang.Object o) Test whether this string is equal to another under the rules of the codepoint collation.
byte[]	getByteArray()
int	getWidth() Get the number of bits needed to hold all the characters in this string
int	hashCode() Compute a hashCode.
long	indexOf(int code, long from) Get the first position, at or beyond start, where a given codepoint appears in this string.
long	indexOf(UnicodeString other, long from) Get the first position, at or beyond start, where another string appears as a substring of this string, comparing codepoints.
long	indexWhere(java.util.function.IntPredicate predicate, long from) Get the position of the first occurrence of the specified codepoint, starting the search at a given position in the string
boolean	isEmpty() Determine whether the string is a zero-length string.
long	length() Get the length of this string, in codepoints
int	length32() Get the length of the string, provided it is less than 2^31 characters
UnicodeString	substring(long start, long end) Get a substring of this string (following the rules of String.substring(int), but measuring Unicode codepoints rather than 16-bit code units)
java.lang.String	toString() Display as a string.

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

asAtomic, checkSubstringBounds, concat, economize, estimatedLength, hasSubstring, indexOf, prefix, requireInt, substring, tidy, verifyCharacters

Methods inherited from class java.lang.Object

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

Field Detail

bytes

protected byte[] bytes

cachedHash

protected int cachedHash

Constructor Detail

Twine24

protected Twine24(byte[] bytes)

Protected constructor

Parameters:

bytes - the Unicode characters, three bytes per character

Twine24

public Twine24(int[] codePoints,
               int used)

Construct a Twine from an array of codepoints.

Parameters:

codePoints - the codepoints making up the string: must not contain any surrogates (that is, codepoints higher than 65535 must be supplied as a single unit)

Twine24

public Twine24(int[] codePoints)

Construct a Twine from an array of codepoints.

Parameters:

codePoints - the codepoints making up the string: must not contain any surrogates (that is, codepoints higher than 65535 must be supplied as a single unit)

Method Detail

getByteArray

public byte[] getByteArray()

length

public long length()

Get the length of this string, in codepoints

Specified by:

length in class UnicodeString

Returns:

the length of the string in Unicode code points

length32

public int length32()

Description copied from class: UnicodeString

Get the length of the string, provided it is less than 2^31 characters

Overrides:

length32 in class UnicodeString

Returns:

the length of the string if it fits within a Java int

substring

public UnicodeString substring(long start,
                               long end)

Get a substring of this string (following the rules of String.substring(int), but measuring Unicode codepoints rather than 16-bit code units)

Specified by:

substring in class UnicodeString

Parameters:

start - the offset of the first character to be included in the result, counting Unicode codepoints

end - the offset of the first character to be excluded from the result, counting Unicode codepoints

Returns:

the substring

codePointAt

public int codePointAt(long index)
                throws java.lang.IndexOutOfBoundsException

Description copied from class: UnicodeString

Get the code point at a given position in the string

Specified by:

codePointAt in class UnicodeString

Parameters:

index - the given position (0-based)

Returns:

the code point at the given position

Throws:

java.lang.IndexOutOfBoundsException - if the index is out of range

indexOf

public long indexOf(int code,
                    long from)

Get the first position, at or beyond start, where a given codepoint appears in this string.

Specified by:

indexOf in class UnicodeString

Parameters:

code - the sought codepoint

from - the position (0-based) where searching is to start (counting in codepoints)

Returns:

the first position where the substring is found, or -1 if it is not found

indexOf

public long indexOf(UnicodeString other,
                    long from)

Get the first position, at or beyond start, where another string appears as a substring of this string, comparing codepoints.

Overrides:

indexOf in class UnicodeString

Parameters:

other - the other (sought) string

from - the position (0-based) where searching is to start (counting in codepoints)

Returns:

the first position where the substring is found, or -1 if it is not found

isEmpty

public boolean isEmpty()

Determine whether the string is a zero-length string. This may be more efficient than testing whether the length is equal to zero

Overrides:

isEmpty in class UnicodeString

Returns:

true if the string is zero length

getWidth

public int getWidth()

Description copied from class: UnicodeString

Get the number of bits needed to hold all the characters in this string

Specified by:

getWidth in class UnicodeString

Returns:

7 for ascii characters (not used??), 8 for latin-1, 16 for BMP, 24 for general Unicode.

codePoints

public IntIterator codePoints()

Get an iterator over the Unicode codepoints in the value. These will always be full codepoints, never surrogates (surrogate pairs are combined where necessary).

Specified by:

codePoints in class UnicodeString

Returns:

a sequence of Unicode codepoints

hashCode

public int hashCode()

Compute a hashCode. All implementations of UnicodeString use compatible hash codes and the hashing algorithm is therefore identical to that for java.lang.String. This means that for strings containing Astral characters, the hash code needs to be computed by decomposing an Astral character into a surrogate pair.

Overrides:

hashCode in class UnicodeString

Returns:

the hash code

equals

public boolean equals(java.lang.Object o)

Test whether this string is equal to another under the rules of the codepoint collation.

Overrides:

equals in class UnicodeString

Parameters:

o - the value to be compared with this value

Returns:

true if the strings are equal on a codepoint-by-codepoint basis

compareTo

public int compareTo(UnicodeString other)

Description copied from class: UnicodeString

Compare this string to another using codepoint comparison

Specified by:

compareTo in interface java.lang.Comparable<UnicodeString>

Overrides:

compareTo in class UnicodeString

Parameters:

other - the other string

Returns:

-1 if this string comes first, 0 if they are equal, +1 if the other string comes first

toString

public java.lang.String toString()

Display as a string.

Overrides:

toString in class java.lang.Object

indexWhere

public long indexWhere(java.util.function.IntPredicate predicate,
                       long from)

Get the position of the first occurrence of the specified codepoint, starting the search at a given position in the string

Overrides:

indexWhere in class UnicodeString

Parameters:

predicate - condition that the codepoint must satisfy

from - the position from which the search should start (0-based)

Returns:

the position (0-based) of the first codepoint to match the predicate, or -1 if not found

Throws:

java.lang.UnsupportedOperationException - if the UnicodeString has not been prepared for codePoint access

details

public java.lang.String details()