public class

Chset

extends Parser<T>
implements Cloneable

java.lang.Object
↳	com.google.gdata.util.parser.Parser<T>
	↳	com.google.gdata.util.parser.Chset

Class Overview

The Chset (character set) parser matches the current character in the parse buffer against an arbitrary character set. The character set is represented as a sorted array of ranges for which a match should be successful. Matching takes O(log nranges) time. There are predefined character sets for matching any character (ANYCHAR), no characters (NOTHING) and some standard 7-bit ASCII ranges (ALNUM, ALPHA, DIGIT, XDIGIT, LOWER, UPPER, WHITESPACE), and ASCII. Note that the character set parser only matches a single character of the parse buffer. The Sequence or Repeat parsers need to be used to match more than one character. The following matches vowels and digits: Parser p = new Chset("uoiea0-9"); p.parse("a") -> matches "a" p.parse("3") -> matches "3" p.parse("b") -> no match

Summary

Constants
char	MAX_ASCII_CHAR
char	MAX_CHAR
char	MIN_CHAR

[Expand]

Inherited Constants

From class com.google.gdata.util.parser.Parser

Fields
public static final Chset	ALNUM
public static final Chset	ALPHA
public static final Chset	ANYCHAR
public static final Chset	ASCII
public static final Chset	DIGIT
public static final Chset	LOWER
public static final Chset	NOTHING
public static final Chset	UPPER
public static final Chset	WHITESPACE
public static final Chset	XDIGIT
private BitSet	asciiSet	A secondary representation for ASCII members of the character set.
private ArrayList<Chset.Range>	ranges

Public Constructors
	Chset() Class constructor for an empty character set.
	Chset(char ch) Class constructor for a character literal.
	Chset(char min, char max) Class constructor for a single character range.
	Chset(String spec) Class constructor that initializes a `Chset` from a string specification.

Public Methods
Object	clone() Returns a clone character set of `this`.
static Chset	difference(Chset left, Chset right) Creates a new character set which matches a character if that character matches the `left` character set but does not match the `right` character set.
static Chset	intersection(Chset left, Chset right) Creates a new character set which matches a character if that character matches both the `left` and `right` character sets.
static Chset	not(Chset subject) Creates a new character set which matches a character if that character does not match the `subject` character set.
int	parse(char[] buf, int start, int end, Object data) Matches `buf[start]` against the character set.
boolean	test(char ch) Tests to see if a single character matches the character set.
String	toString()
static Chset	union(Chset left, Chset right) Creates a new character set which matches a character if that character matches either the `left` or `right` character sets.
static Chset	xor(Chset left, Chset right) Creates a new character set which matches a character if that character matches the `left` character set or the `right` character set, but not both.

Protected Methods
void	clear(char min, char max)
void	set(char min, char max)
int	size() Returns the size of the range array.
boolean	testRanges(char ch) Tests to see if a single character matches the character set, but only looks at the ranges representation.

[Expand]

Inherited Methods

From class com.google.gdata.util.parser.Parser

final <U extends T> Parser<U>	action(Callback<U> callback) Creates a `Action` that will fire and call `Callback.handle` whenever `this` matches.
static <T> Parser<T>	alternative(Parser<? super T> left, Parser<? super T> right) Creates an `Alternative` parser from the `left` and `right` sub-parsers.
static <T> Parser<T>	difference(Parser<? super T> left, Parser<? super T> right) Creates a `Difference` parser from the `left` and `right` sub-parsers.
static <T> Parser<T>	intersection(Parser<? super T> left, Parser<? super T> right) Creates an `Intersection` parser from the `left` and `right` sub-parsers.
final Parser<T>	list(Parser<? super T> sep) Creates a `Parser` that matches a sequence of `this` parsers separated by `sep` parsers.
final Parser<T>	optional() Creates a `Repeat` parser that matches `this` either 0 or 1 times.
final int	parse(String str, T udata) Convenience routine to parse a string.
abstract int	parse(char[] buf, int start, int end, T udata) The parse interface that subclasses must implement.
final int	parse(Reader reader, T udata) Convenience routine to parse a `java.io.Reader`.
final int	parse(char[] buf, T udata) Convenience routine to parse a character array.
final Parser<T>	plus() Creates a `Repeat` parser that matches `this` 1 or more times.
final Parser<T>	repeat(int min, int max) Creates a `Repeat` parser that matches `this` at least `min` times and not mroe than `max` times.
final Parser<T>	repeat(int count) Creates a `Repeat` parser that matches `this` exactly `count` times.
static <T> Parser<T>	sequence(Parser<? super T> one, Parser<? super T> two, Parser<? super T> three, Parser<? super T> four) Creates a sequence of four parsers.
static <T> Parser<T>	sequence(Parser<? super T> one, Parser<? super T> two, Parser<? super T> three, Parser<? super T> four, Parser<? super T> five) Creates a sequence of five parsers.
static <T> Parser<T>	sequence(Parser<? super T> one, Parser<? super T> two, Parser<? super T> three) Creates a `Sequence` parser from parsers `one`, `two` and `three` sub-parsers.
static <T> Parser<T>	sequence(Parser<? super T> left, Parser<? super T> right) Creates a `Sequence` parser from the `left` and `right` sub-parsers.
final Parser<T>	star() Creates a `Repeat` parser that matches `this` 0 or more times.

From class java.lang.Object

Constants

private static final char MAX_ASCII_CHAR

Constant Value: 127 (0x0000007f)

protected static final char MAX_CHAR

Constant Value: 65535 (0x0000ffff)

protected static final char MIN_CHAR

Constant Value: 0 (0x00000000)

Fields

public static final Chset ALNUM

public static final Chset ALPHA

public static final Chset ANYCHAR

public static final Chset ASCII

public static final Chset DIGIT

public static final Chset LOWER

public static final Chset NOTHING

public static final Chset UPPER

public static final Chset WHITESPACE

public static final Chset XDIGIT

private BitSet asciiSet

A secondary representation for ASCII members of the character set. Maintaining this bitmap allows us to check ASCII characters for set membership quickly.

private ArrayList<Chset.Range> ranges

Public Constructors

public Chset ()

Class constructor for an empty character set.

public Chset (char ch)

Class constructor for a character literal.

Parameters

ch	The character literal for this character set to match against.

public Chset (char min, char max)

Class constructor for a single character range. The range is inclusive: all character including min and max match.

Parameters

min	The beginning of the character range.
max	The end of the character range.

public Chset (String spec)

Class constructor that initializes a Chset from a string specification.

Parameters

spec	The string specification to intialize the `Chset` from.

Public Methods

public Object clone ()

Returns a clone character set of this.

public static Chset difference (Chset left, Chset right)

Creates a new character set which matches a character if that character matches the left character set but does not match the right character set. left - right

Parameters

left	The left source character set.
right	The right source character set.

public static Chset intersection (Chset left, Chset right)

Creates a new character set which matches a character if that character matches both the left and right character sets. left & right --> left - ~right

Parameters

left	The left source character set.
right	The right source character set.

public static Chset not (Chset subject)

Creates a new character set which matches a character if that character does not match the subject character set. This operation is implemented by taking the difference of the ANYCHAR character set and the subject character set. ~subject --> anychar - subject

Parameters

subject	The source character set.

public int parse (char[] buf, int start, int end, Object data)

Matches buf[start] against the character set.

Parameters

buf	The character array to match against.
start	The start offset of data within the character array to match against.
end	The end offset of data within the character array to match against.
data	User defined object that is passed to `Callback.handle` when an `Action` fires.

public boolean test (char ch)

Tests to see if a single character matches the character set.

Parameters

ch	The character to test.

public String toString ()

public static Chset union (Chset left, Chset right)

Creates a new character set which matches a character if that character matches either the left or right character sets. left | right

Parameters

left	The left source character set.
right	The right source character set.

public static Chset xor (Chset left, Chset right)

Creates a new character set which matches a character if that character matches the left character set or the right character set, but not both. left ^ right --> (left - right) | (right - left)

Parameters

left	The left source character set.
right	The right source character set.

Protected Methods

protected void clear (char min, char max)

Parameters

min
max

protected void set (char min, char max)

Parameters

min
max

protected int size ()

Returns the size of the range array.

protected boolean testRanges (char ch)

Tests to see if a single character matches the character set, but only looks at the ranges representation.

Parameters

ch	The character to test.

Interfaces

Classes

Chset

Class Overview

See Also

Summary

Constants

private static final char MAX_ASCII_CHAR

protected static final char MAX_CHAR

protected static final char MIN_CHAR

Fields

public static final Chset ALNUM

public static final Chset ALPHA

public static final Chset ANYCHAR

public static final Chset ASCII

public static final Chset DIGIT

public static final Chset LOWER

public static final Chset NOTHING

public static final Chset UPPER

public static final Chset WHITESPACE

public static final Chset XDIGIT

private BitSet asciiSet

private ArrayList<Chset.Range> ranges

Public Constructors

public Chset ()

public Chset (char ch)

Parameters

public Chset (char min, char max)

Parameters

public Chset (String spec)

Parameters

Public Methods

public Object clone ()

public static Chset difference (Chset left, Chset right)

Parameters

public static Chset intersection (Chset left, Chset right)

Parameters

public static Chset not (Chset subject)

Parameters

public int parse (char[] buf, int start, int end, Object data)

Parameters

See Also

public boolean test (char ch)

Parameters

public String toString ()

public static Chset union (Chset left, Chset right)

Parameters

public static Chset xor (Chset left, Chset right)

Parameters

Protected Methods

protected void clear (char min, char max)

Parameters

See Also

protected void set (char min, char max)

Parameters

See Also

protected int size ()

protected boolean testRanges (char ch)

Parameters