This class supports two APIs. The first is modeled after Java 2's
* java.util.Set interface, although this class does not
* implement that interface. All methods of Set are
* supported, with the modification that they take a character range
* or single character instead of an Object, and they
* take a UnicodeSet instead of a Collection.
*
*
The second API is the
* applyPattern()/toPattern() API from the
* Format-derived classes. Unlike the
* methods that add characters, add categories, and control the logic
* of the set, the method applyPattern() sets all
* attributes of a UnicodeSet at once, based on a
* string pattern.
*
*
In addition, the set complement operation is supported through
* the complement() method.
*
*
Pattern syntax
* * Patterns are accepted by the constructors and the *applyPattern() methods and returned by the
* toPattern() method. These patterns follow a syntax
* similar to that employed by version 8 regular expression character
* classes:
*
* * * Patterns specify individual characters, ranges of characters, and * Unicode character categories. When elements are concatenated, they * specify their union. To complement a set, place a '^' immediately * after the opening '[' or '[:'. In any other location, '^' has no * special meaning. * ** pattern := ('[' '^'? item* ']') | ('[:' '^'? category ':]')* *
* item := char | (char '-' char) | pattern-expr
* pattern-expr := pattern | pattern-expr pattern | pattern-expr op pattern
* op := '&' | '-'
* special := '[' | ']' | '-'
* char := any character that is not special | * ('\' any character) | * ('\\u' hex hex hex hex)
* hex := any hex digit, as defined by Character.digit(c, 16) *
Legend: * **
*a:=b*amay be replaced by *b*a?*zero or one instance of a
*a**one or more instances of a
*a|b*either aorb
*'a'*the literal string between the quotes *
Ranges are indicated by placing two a '-' between two * characters, as in "a-z". This specifies the range of all * characters from the left to the right, in Unicode order. If the * left and right characters are the same, then the range consists of * just that character. If the left character is greater than the * right character it is a syntax error. If a '-' occurs as the first * character after the opening '[' or '[^', or if it occurs as the * last character before the closing ']', then it is taken as a * literal. Thus "[a\-b]", "[-ab]", and "[ab-]" all indicate the same * set of three characters, 'a', 'b', and '-'. * *
Sets may be intersected using the '&' operator or the asymmetric * set difference may be taken using the '-' operator, for example, * "[[:L:]&[\u0000-\u0FFF]]" indicates the set of all Unicode letters * with values less than 4096. Operators ('&' and '|') have equal * precedence and bind left-to-right. Thus * "[[:L:]-[a-z]-[\u0100-\u01FF]]" is equivalent to * "[[[:L:]-[a-z]]-[\u0100-\u01FF]]". This only really matters for * difference; intersection is commutative. * *
[a] | The set containing 'a' * |
[a-z] | The set containing 'a' * through 'z' and all letters in between, in Unicode order * |
[^a-z] | The set containing * all characters but 'a' through 'z', * that is, U+0000 through 'a'-1 and 'z'+1 through U+FFFF * |
[[pat1][pat2]]
* | The union of sets specified by pat1 and pat2 * |
[[pat1]&[pat2]]
* | The intersection of sets specified by pat1 and pat2 * |
[[pat1]-[pat2]]
* | The asymmetric difference of sets specified by pat1 and * pat2 * |
[:Lu:]
* | The set of characters belonging to the given
* Unicode category, as defined by Character.getType(); in
* this case, Unicode uppercase letters
* |
[:L:]
* | The set of characters belonging to all Unicode categories
* starting wih 'L', that is, [[:Lu:][:Ll:][:Lt:][:Lm:][:Lo:]].
* |
Character categories.
*
* Character categories are specified using the POSIX-like syntax
* '[:Lu:]'. The complement of a category is specified by inserting
* '^' after the opening '[:'. The following category names are
* recognized. Actual determination of category data uses
* Unicode::getType(), so it reflects the underlying
* data used by Unicode.
*
*
* Normative * Mn = Mark, Non-Spacing * Mc = Mark, Spacing Combining * Me = Mark, Enclosing * * Nd = Number, Decimal Digit * Nl = Number, Letter * No = Number, Other * * Zs = Separator, Space * Zl = Separator, Line * Zp = Separator, Paragraph * * Cc = Other, Control * Cf = Other, Format * Cs = Other, Surrogate * Co = Other, Private Use * Cn = Other, Not Assigned * * Informative * Lu = Letter, Uppercase * Ll = Letter, Lowercase * Lt = Letter, Titlecase * Lm = Letter, Modifier * Lo = Letter, Other * * Pc = Punctuation, Connector * Pd = Punctuation, Dash * Ps = Punctuation, Open * Pe = Punctuation, Close * Pi = Punctuation, Initial quote * Pf = Punctuation, Final quote * Po = Punctuation, Other * * Sm = Symbol, Math * Sc = Symbol, Currency * Sk = Symbol, Modifier * So = Symbol, Other ** * @author Alan Liu */ class U_I18N_API UnicodeSet { /** * The internal representation is a UnicodeString of even length. * Each pair of characters represents a range that is included in * the set. A single character c is represented as cc. Thus, the * ranges in the set are (a,b), a and b inclusive, where a = * pairs.charAt(i) and b = pairs.charAt(i+1) for all even i, 0 <= * i <= pairs.length()-2. Pairs are always stored in ascending * Unicode order. Pairs are always stored in shortest form. For * example, if the pair "hh", representing the single character * 'h', is added to the pairs list "agik", representing the ranges * 'a'-'g' and 'i'-'k', the result is "ak", not "aghhik". */ UnicodeString pairs; static const UnicodeString CATEGORY_NAMES; /** * A cache mapping character category integers, as returned by * Unicode::getType(), to pairs strings. Entries are initially * zero length and are filled in on demand. */ static UnicodeString* CATEGORY_PAIRS_CACHE; /** * Delimiter string used in patterns to close a category reference: * ":]". Example: "[:Lu:]". */ static const UnicodeString CATEGORY_CLOSE; /** * Delimiter char beginning a variable reference: * "{". Example: "{var}". */ static const UChar VARIABLE_REF_OPEN; /** * Delimiter char ending a variable reference: * "}". Example: "{var}". */ static const UChar VARIABLE_REF_CLOSE; //---------------------------------------------------------------- // Debugging and testing //---------------------------------------------------------------- public: /** * Return the representation of this set as a list of character * ranges. Ranges are listed in ascending Unicode order. For * example, the set [a-zA-M3] is represented as "33AMaz". */ const UnicodeString& getPairs(void) const; //---------------------------------------------------------------- // Constructors &c //---------------------------------------------------------------- public: /** * Constructs an empty set. */ UnicodeSet(); /** * Constructs a set from the given pattern. See the class * description for the syntax of the pattern language. * @param pattern a string specifying what characters are in the set * @exception
IllegalArgumentException if the pattern
* contains a syntax error.
*/
UnicodeSet(const UnicodeString& pattern,
UErrorCode& status);
/**
* Constructs a set from the given pattern, optionally ignoring
* white space. See the class description for the syntax of the
* pattern language.
* @param pattern a string specifying what characters are in the set
* @param ignoreSpaces if true, all spaces in the
* pattern are ignored, except those preceded by '\\'. Spaces are
* those characters for which Character.isSpaceChar()
* is true.
* @exception IllegalArgumentException if the pattern
* contains a syntax error.
*/
UnicodeSet(const UnicodeString& pattern, bool_t ignoreSpaces,
UErrorCode& status);
/**
* Constructs a set from the given Unicode character category.
* @param category an integer indicating the character category as
* returned by Character.getType().
* @exception IllegalArgumentException if the given
* category is invalid.
*/
UnicodeSet(int8_t category, UErrorCode& status);
/**
* Constructs a set that is identical to the given UnicodeSet.
*/
UnicodeSet(const UnicodeSet& o);
/**
* Destructs the set.
*/
virtual ~UnicodeSet();
/**
* Assigns this object to be a copy of another.
*/
UnicodeSet& operator=(const UnicodeSet& o);
/**
* Compares the specified object with this set for equality. Returns
* true if the two sets
* have the same size, and every member of the specified set is
* contained in this set (or equivalently, every member of this set is
* contained in the specified set).
*
* @param o set to be compared for equality with this set.
* @return true if the specified set is equal to this set.
*/
virtual bool_t operator==(const UnicodeSet& o) const;
/**
* Compares the specified object with this set for equality. Returns
* true if the specified set is not equal to this set.
*/
bool_t operator!=(const UnicodeSet& o) const;
/**
* Returns the hash code value for this set.
*
* @return the hash code value for this set.
* @see Object#hashCode()
*/
virtual int32_t hashCode(void) const;
//----------------------------------------------------------------
// Public API
//----------------------------------------------------------------
/**
* Modifies this set to represent the set specified by the given
* pattern, optionally ignoring white space. See the class
* description for the syntax of the pattern language.
* @param pattern a string specifying what characters are in the set
* @param ignoreSpaces if true, all spaces in the
* pattern are ignored. Spaces are those characters for which
* Character.isSpaceChar() is true.
* Characters preceded by '\\' are escaped, losing any special
* meaning they otherwise have. Spaces may be included by
* escaping them.
* @exception IllegalArgumentException if the pattern
* contains a syntax error.
*/
virtual void applyPattern(const UnicodeString& pattern,
bool_t ignoreSpaces,
UErrorCode& status);
/**
* Modifies this set to represent the set specified by the given
* pattern. See the class description for the syntax of the pattern
* language.
* @param pattern a string specifying what characters are in the set
* @exception IllegalArgumentException if the pattern
* contains a syntax error.
*/
void applyPattern(const UnicodeString& pattern,
UErrorCode& status);
/**
* Returns a string representation of this set. If the result of
* calling this function is passed to a UnicodeSet constructor, it
* will produce another set that is equal to this one.
*/
virtual UnicodeString& toPattern(UnicodeString& result) const;
/**
* Returns the number of elements in this set (its cardinality),
* n, where 0 <= n <= 65536.
*
* @return the number of elements in this set (its cardinality).
*/
virtual int32_t size(void) const;
/**
* Returns true if this set contains no elements.
*
* @return true if this set contains no elements.
*/
virtual bool_t isEmpty(void) const;
/**
* Returns true if this set contains the specified range
* of chars.
*
* @return true if this set contains the specified range
* of chars.
*/
virtual bool_t contains(UChar first, UChar last) const;
/**
* Returns true if this set contains the specified char.
*
* @return true if this set contains the specified char.
*/
virtual bool_t contains(UChar c) const;
/**
* Adds the specified range to this set if it is not already
* present. If this set already contains the specified range,
* the call leaves this set unchanged. If last > first
* then an empty range is added, leaving the set unchanged.
*
* @param first first character, inclusive, of range to be added
* to this set.
* @param last last character, inclusive, of range to be added
* to this set.
*/
virtual void add(UChar first, UChar last);
/**
* Adds the specified character to this set if it is not already
* present. If this set already contains the specified character,
* the call leaves this set unchanged.
*/
virtual void add(UChar c);
/**
* Removes the specified range from this set if it is present.
* The set will not contain the specified range once the call
* returns. If last > first then an empty range is
* removed, leaving the set unchanged.
*
* @param first first character, inclusive, of range to be removed
* from this set.
* @param last last character, inclusive, of range to be removed
* from this set.
*/
virtual void remove(UChar first, UChar last);
/**
* Removes the specified character from this set if it is present.
* The set will not contain the specified range once the call
* returns.
*/
virtual void remove(UChar c);
/**
* Returns true if the specified set is a subset
* of this set.
*
* @param c set to be checked for containment in this set.
* @return true if this set contains all of the elements of the
* specified set.
*/
virtual bool_t containsAll(const UnicodeSet& c) const;
/**
* Adds all of the elements in the specified set to this set if
* they're not already present. This operation effectively
* modifies this set so that its value is the union of the two
* sets. The behavior of this operation is unspecified if the specified
* collection is modified while the operation is in progress.
*
* @param c set whose elements are to be added to this set.
* @see #add(char, char)
*/
virtual void addAll(const UnicodeSet& c);
/**
* Retains only the elements in this set that are contained in the
* specified set. In other words, removes from this set all of
* its elements that are not contained in the specified set. This
* operation effectively modifies this set so that its value is
* the intersection of the two sets.
*
* @param c set that defines which elements this set will retain.
*/
virtual void retainAll(const UnicodeSet& c);
/**
* Removes from this set all of its elements that are contained in the
* specified set. This operation effectively modifies this
* set so that its value is the asymmetric set difference of
* the two sets.
*
* @param c set that defines which elements will be removed from
* this set.
*/
virtual void removeAll(const UnicodeSet& c);
/**
* Inverts this set. This operation modifies this set so that
* its value is its complement. This is equivalent to the pseudo code:
* this = new CharSet("[\u0000-\uFFFF]").removeAll(this).
*/
virtual void complement(void);
/**
* Removes all of the elements from this set. This set will be
* empty after this call returns.
*/
virtual void clear(void);
//----------------------------------------------------------------
// Implementation: Pattern parsing
//----------------------------------------------------------------
private:
/**
* Parses the given pattern, starting at the given position. The
* character at pattern.charAt(pos.getIndex()) must be '[', or the
* parse fails. Parsing continues until the corresponding closing
* ']'. If a syntax error is encountered between the opening and
* closing brace, the parse fails. Upon return from a successful
* parse, the ParsePosition is updated to point to the character
* following the closing ']', and a StringBuffer containing a
* pairs list for the parsed pattern is returned. This method calls
* itself recursively to parse embedded subpatterns.
*
* @param pattern the string containing the pattern to be parsed.
* The portion of the string from pos.getIndex(), which must be a
* '[', to the corresponding closing ']', is parsed.
* @param pos upon entry, the position at which to being parsing.
* The character at pattern.charAt(pos.getIndex()) must be a '['.
* Upon return from a successful parse, pos.getIndex() is either
* the character after the closing ']' of the parsed pattern, or
* pattern.length() if the closing ']' is the last character of
* the pattern string.
* @return a StringBuffer containing a pairs list for the parsed
* substring of pattern
* @exception IllegalArgumentException if the parse fails.
*/
static UnicodeString& parse(UnicodeString& pairsBuf /*result*/,
const UnicodeString& pattern,
ParsePosition& pos,
const TransliterationRuleData* data,
UErrorCode& status);
//----------------------------------------------------------------
// Implementation: Efficient in-place union & difference
//----------------------------------------------------------------
/**
* Performs a union operation: adds the range 'c'-'d' to the given
* pairs list. The pairs list is modified in place. The result
* is normalized (in order and as short as possible). For
* example, addPair("am", 'l', 'q') => "aq". addPair("ampz", 'n',
* 'o') => "az".
*/
static void addPair(UnicodeString& pairs, UChar c, UChar d);
/**
* Performs an asymmetric difference: removes the range 'c'-'d'
* from the pairs list. The pairs list is modified in place. The
* result is normalized (in order and as short as possible). For
* example, removePair("am", 'l', 'q') => "ak".
* removePair("ampz", 'l', 'q') => "akrz".
*/
static void removePair(UnicodeString& pairs, UChar c, UChar d);
//----------------------------------------------------------------
// Implementation: Fundamental operators
//----------------------------------------------------------------
/**
* Changes the pairs list to represent the complement of the set it
* currently represents. The pairs list will be normalized (in
* order and in shortest possible form) if the original pairs list
* was normalized.
*/
static void doComplement(UnicodeString& pairs);
/**
* Given two pairs lists, changes the first in place to represent
* the union of the two sets.
*/
static void doUnion(UnicodeString& pairs, const UnicodeString& c2);
/**
* Given two pairs lists, changes the first in place to represent
* the asymmetric difference of the two sets.
*/
static void doDifference(UnicodeString& pairs, const UnicodeString& pairs2);
/**
* Given two pairs lists, changes the first in place to represent
* the intersection of the two sets.
*/
static void doIntersection(UnicodeString& pairs, const UnicodeString& c2);
//----------------------------------------------------------------
// Implementation: Generation of pairs for Unicode categories
//----------------------------------------------------------------
/**
* Returns a pairs string for the given category, given its name.
* The category name must be either a two-letter name, such as
* "Lu", or a one letter name, such as "L". One-letter names
* indicate the logical union of all two-letter names that start
* with that letter. Case is significant. If the name starts
* with the character '^' then the complement of the given
* character set is returned.
*
* Although individual categories such as "Lu" are cached, we do
* not currently cache single-letter categories such as "L" or
* complements such as "^Lu" or "^L". It would be easy to cache
* these as well in a hashtable should the need arise.
*/
static UnicodeString& getCategoryPairs(UnicodeString& result,
const UnicodeString& catName,
UErrorCode& status);
/**
* Returns a pairs string for the given category. This string is
* cached and returned again if this method is called again with
* the same parameter.
*/
static const UnicodeString& getCategoryPairs(int8_t cat);
//----------------------------------------------------------------
// Implementation: Utility methods
//----------------------------------------------------------------
/**
* Returns the character after the given position, or '\uFFFF' if
* there is none.
*/
static UChar charAfter(const UnicodeString& str, int32_t i);
};
inline void UnicodeSet::applyPattern(const UnicodeString& pattern,
UErrorCode& status) {
applyPattern(pattern, FALSE, status);
}
inline bool_t UnicodeSet::operator!=(const UnicodeSet& o) const {
return !operator==(o);
}
#endif