| /* |
| *************************************************************************** |
| * Copyright (C) 1999-2002 International Business Machines Corporation * |
| * and others. All rights reserved. * |
| *************************************************************************** |
| |
| ********************************************************************** |
| * Date Name Description |
| * 10/22/99 alan Creation. |
| * 11/11/99 rgillam Complete port from Java. |
| ********************************************************************** |
| */ |
| |
| #ifndef RBBI_H |
| #define RBBI_H |
| |
| #include "unicode/utypes.h" |
| #include "unicode/brkiter.h" |
| #include "unicode/udata.h" |
| #include "unicode/parseerr.h" |
| #include "utrie.h" |
| |
| #include "rbbidata.h" |
| |
| U_NAMESPACE_BEGIN |
| |
| class RuleBasedBreakIteratorTables; |
| class BreakIterator; |
| |
| |
| |
| /** |
| * <p>A subclass of BreakIterator whose behavior is specified using a list of rules.</p> |
| * |
| * <p>There are two kinds of rules, which are separated by semicolons: <i>variable definitions</i> |
| * and <i>regular expressions.</i></p> |
| * |
| * <p>A varialbe definition defines a variable name that can be used in subsequent expressions. |
| * It consists of a name preceded by a dollar sign, an equals |
| * sign, and an expression. |
| * A $variable is visible after its definition. |
| * Variable definitions can contain other variables, as |
| * long as those variables have been defined first. Variables are generally used to |
| * make the regular expressions (which can get quite complex) shorter and easier to read. |
| * They typically define either character categories or commonly-used subexpressions.</p> |
| * |
| * <p>A regular expression uses a subset of the normal Unix regular-expression syntax, and |
| * defines a sequence of characters to be kept together. With one significant exception, the |
| * iterator uses a longest-possible-match algorithm when matching text to regular |
| * expressions. The iterator also treats descriptions containing multiple regular expressions |
| * as if they were ORed together (i.e., as if they were separated by |).</p> |
| * |
| * <p>The special characters recognized by the regular-expression parser are as follows:</p> |
| * |
| * <blockquote> |
| * <table border="1" width="100%"> |
| * <tr> |
| * <td width="6%">*</td> |
| * <td width="94%">Specifies that the expression preceding the asterisk may occur any number |
| * of times (including not at all).</td> |
| * </tr> |
| * <tr> |
| * <td width="6%">()</td> |
| * <td width="94%">Encloses a sequence of characters. If followed by *, the sequence |
| * repeats. Otherwise, the parentheses are just a grouping device and a way to delimit |
| * the ends of expressions containing |.</td> |
| * </tr> |
| * <tr> |
| * <td width="6%">|</td> |
| * <td width="94%">Separates two alternative sequences of characters. Either one |
| * sequence or the other, but not both, matches this expression.</td> |
| * </tr> |
| * <tr> |
| * <td width="6%">.</td> |
| * <td width="94%">Matches any character.</td> |
| * </tr> |
| * <tr> |
| * <td width="6%">[]</td> |
| * <td width="94%">Specify a set of characters. A [] expression will |
| * match any single character that is specified in the [] expression. For more on the |
| * syntax of [] expressions, see the ICU User Guide description of UnicodeSet.</td> |
| * </tr> |
| * <tr> |
| * <td width="6%">/</td> |
| * <td width="94%">Specifies where the break position should go if text matches this |
| * expression. (e.g., "[a-z]*/[:Zs:]*1" will match if the iterator sees a run |
| * of letters, followed by a run of whitespace, followed by a digit, but the break position |
| * will actually go before the whitespace). Expressions that don't contain / put the |
| * break position at the end of the matching text.</td> |
| * </tr> |
| * <tr> |
| * <td width="6%">\</td> |
| * <td width="94%">Escape character. The \ itself is ignored, but causes the next |
| * character to be treated as literal character. Except for letters and numbers, |
| * characters in the ASCII range must be escaped to be considered as literals.</td> |
| * </tr> |
| * <tr> |
| * <td width="6%">!</td> |
| * <td width="94%">If ! appears at the beginning of a regular expression, it tells the regexp |
| * parser that this expression specifies the backwards-iteration behavior of the iterator, |
| * and not its normal iteration behavior. The backwards rules must move the |
| * iterator to a safe position at or before the previous break position; forwards rules |
| * will then be used to find the exact previous position</td> |
| * </tr> |
| * <tr> |
| * <td width="6%"><em>(all others)</em></td> |
| * <td width="94%">All other characters are treated as literal characters, which must match |
| * the corresponding character(s) in the text exactly.</td> |
| * </tr> |
| * </table> |
| * </blockquote> |
| */ |
| |
| |
| |
| |
| class U_COMMON_API RuleBasedBreakIterator : public BreakIterator { |
| |
| protected: |
| /** |
| * The character iterator through which this BreakIterator accesses the text |
| */ |
| CharacterIterator* fText; |
| |
| // |
| // The rule data for this BreakIterator instance |
| // |
| RBBIDataWrapper *fData; |
| UTrie *fCharMappings; |
| |
| // Rule {tag} value for the most recent match. |
| int32_t fLastBreakTag; |
| |
| // |
| // Counter for the number of characters encountered with the "dictionary" |
| // flag set. Normal RBBI iterators don't use it, although the code |
| // for updating it is live. Dictionary Based break iterators (a subclass |
| // of us) access this field directly. |
| // |
| uint32_t fDictionaryCharCount; |
| |
| // |
| // Debugging flag. |
| // |
| static UBool fTrace; |
| |
| |
| |
| private: |
| /** |
| * Class ID |
| */ |
| static const char fgClassID; |
| |
| protected: |
| //======================================================================= |
| // constructors |
| //======================================================================= |
| |
| // This constructor uses the udata interface to create a BreakIterator whose |
| // internal tables live in a memory-mapped file. "image" is a pointer to the |
| // beginning of that file. |
| RuleBasedBreakIterator(UDataMemory* image, UErrorCode &status); |
| |
| // |
| // Constructor from a flattened set of RBBI data in malloced memory. |
| // RulesBasedBreakIterators built from a custom set of rules |
| // are created via this constructor; the rules are compiled |
| // into memory, then the break iterator is constructed here. |
| // |
| // The break iterator adopts the memory, and will |
| // uprv_free() it when done. |
| RuleBasedBreakIterator(RBBIDataHeader* data, UErrorCode &status); |
| |
| friend class RBBIRuleBuilder; |
| friend class BreakIterator; |
| |
| |
| |
| public: |
| |
| /** Default constructor. Creates an empty shell of an iterator, with no |
| * rules or text to iterate over. Object can subsequently be assigned. |
| */ |
| RuleBasedBreakIterator(); |
| |
| /** |
| * Copy constructor. Will produce a break iterator with the same behavior, |
| * and which iterates over the same text, as the one passed in. |
| * @param that The RuleBasedBreakIterator passed to be copied |
| */ |
| RuleBasedBreakIterator(const RuleBasedBreakIterator& that); |
| |
| /** |
| * Construct a RuleBasedBreakIterator from a set of rules supplied as a string. |
| */ |
| RuleBasedBreakIterator( const UnicodeString &rules, |
| UParseError &parseError, |
| UErrorCode &status); |
| /** |
| * Destructor |
| */ |
| virtual ~RuleBasedBreakIterator(); |
| |
| /** |
| * Assignment operator. Sets this iterator to have the same behavior, |
| * and iterate over the same text, as the one passed in. |
| * @param that The RuleBasedBreakItertor passed in |
| * @return the newly created RuleBasedBreakIterator |
| */ |
| RuleBasedBreakIterator& operator=(const RuleBasedBreakIterator& that); |
| |
| /** |
| * Equality operator. Returns TRUE if both BreakIterators are of the |
| * same class, have the same behavior, and iterate over the same text. |
| * @param that The BreakIterator to be compared for equality |
| * @Return TRUE if both BreakIterators are of the |
| * same class, have the same behavior, and iterate over the same text. |
| */ |
| virtual UBool operator==(const BreakIterator& that) const; |
| |
| /** |
| * Not-equal operator. If operator== returns TRUE, this returns FALSE, |
| * and vice versa. |
| * @param that The BreakIterator to be compared for inequality |
| * @return TRUE if both BreakIterators are not same. |
| */ |
| UBool operator!=(const BreakIterator& that) const; |
| |
| /** |
| * Returns a newly-constructed RuleBasedBreakIterator with the same |
| * behavior, and iterating over the same text, as this one. |
| * Differs from the copy constructor in that it is polymorphic, and |
| * will correctly clone (copy) a derived class. |
| */ |
| virtual BreakIterator* clone() const; |
| |
| /** |
| * Compute a hash code for this BreakIterator |
| * @return A hash code |
| */ |
| virtual int32_t hashCode(void) const; |
| |
| /** |
| * Returns the description used to create this iterator |
| * @return the description used to create this iterator |
| */ |
| virtual const UnicodeString& getRules(void) const; |
| |
| //======================================================================= |
| // BreakIterator overrides |
| //======================================================================= |
| |
| /** |
| * Return a CharacterIterator over the text being analyzed. This version |
| * of this method returns the actual CharacterIterator we're using internally. |
| * Changing the state of this iterator can have undefined consequences. If |
| * you need to change it, clone it first. |
| * @return An iterator over the text being analyzed. |
| */ |
| virtual const CharacterIterator& getText(void) const; |
| |
| |
| /** |
| * Set the iterator to analyze a new piece of text. This function resets |
| * the current iteration position to the beginning of the text. |
| * @param newText An iterator over the text to analyze. The BreakIterator |
| * takes ownership of the character iterator. The caller MUST NOT delete it! |
| */ |
| virtual void adoptText(CharacterIterator* newText); |
| |
| /** |
| * Set the iterator to analyze a new piece of text. This function resets |
| * the current iteration position to the beginning of the text. |
| * @param newText The text to analyze. |
| */ |
| virtual void setText(const UnicodeString& newText); |
| |
| /** |
| * Sets the current iteration position to the beginning of the text. |
| * (i.e., the CharacterIterator's starting offset). |
| * @return The offset of the beginning of the text. |
| */ |
| virtual int32_t first(void); |
| |
| /** |
| * Sets the current iteration position to the end of the text. |
| * (i.e., the CharacterIterator's ending offset). |
| * @return The text's past-the-end offset. |
| */ |
| virtual int32_t last(void); |
| |
| /** |
| * Advances the iterator either forward or backward the specified number of steps. |
| * Negative values move backward, and positive values move forward. This is |
| * equivalent to repeatedly calling next() or previous(). |
| * @param n The number of steps to move. The sign indicates the direction |
| * (negative is backwards, and positive is forwards). |
| * @return The character offset of the boundary position n boundaries away from |
| * the current one. |
| */ |
| virtual int32_t next(int32_t n); |
| |
| /** |
| * Advances the iterator to the next boundary position. |
| * @return The position of the first boundary after this one. |
| */ |
| virtual int32_t next(void); |
| |
| /** |
| * Advances the iterator backwards, to the last boundary preceding this one. |
| * @return The position of the last boundary position preceding this one. |
| */ |
| virtual int32_t previous(void); |
| |
| /** |
| * Sets the iterator to refer to the first boundary position following |
| * the specified position. |
| * @param offset The position from which to begin searching for a break position. |
| * @return The position of the first break after the current position. |
| */ |
| virtual int32_t following(int32_t offset); |
| |
| /** |
| * Sets the iterator to refer to the last boundary position before the |
| * specified position. |
| * @param offset The position to begin searching for a break from. |
| * @return The position of the last boundary before the starting position. |
| */ |
| virtual int32_t preceding(int32_t offset); |
| |
| /** |
| * Returns true if the specfied position is a boundary position. As a side |
| * effect, leaves the iterator pointing to the first boundary position at |
| * or after "offset". |
| * @param offset the offset to check. |
| * @return True if "offset" is a boundary position. |
| */ |
| virtual UBool isBoundary(int32_t offset); |
| |
| /** |
| * Returns the current iteration position. |
| * @return The current iteration position. |
| */ |
| virtual int32_t current(void) const; |
| |
| |
| /** |
| * Return the status from the break rule that determined the most recently |
| * returned break position. The values appear in the rule source |
| * within brackets, {123}, for example. For rules that do not specify a |
| * status, a default value of 0 is returned. |
| * @return the status from the break rule that determined the most recently |
| * returned break position. |
| */ |
| virtual int32_t getRuleStatus() const; |
| |
| /** |
| * Returns a unique class ID POLYMORPHICALLY. Pure virtual override. |
| * This method is to implement a simple version of RTTI, since not all |
| * C++ compilers support genuine RTTI. Polymorphic operator==() and |
| * clone() methods call this method. |
| * |
| * @return The class ID for this object. All objects of a |
| * given class have the same class ID. Objects of |
| * other classes have different class IDs. |
| */ |
| inline virtual UClassID getDynamicClassID(void) const; |
| |
| /** |
| * Returns the class ID for this class. This is useful only for |
| * comparing to a return value from getDynamicClassID(). For example: |
| * |
| * Base* polymorphic_pointer = createPolymorphicObject(); |
| * if (polymorphic_pointer->getDynamicClassID() == |
| * Derived::getStaticClassID()) ... |
| * |
| * @return The class ID for all objects of this class. |
| */ |
| inline static UClassID getStaticClassID(void); |
| |
| virtual BreakIterator * createBufferClone(void *stackBuffer, |
| int32_t &BufferSize, |
| UErrorCode &status); |
| |
| |
| /** |
| * Return the binary form of compiled break rules, |
| * which can then be used to create a new break iterator at some |
| * time in the future. Creating a break iterator in this way |
| * is much faster than building one from the source form of the |
| * break rules. |
| * |
| * The binary data is can only be used with the same version of ICU |
| * and on the same platform type (processor endian-ness) |
| * |
| * @return A pointer to the binary (compiled) rule data. The storage |
| * belongs to the RulesBasedBreakIterator object, no the |
| * caller, and must not be modified or deleted. |
| */ |
| virtual const uint8_t *getBinaryRules(uint32_t &length); |
| |
| |
| #ifdef RBBI_DEBUG |
| void debugDumpTables() const; |
| #endif |
| |
| |
| protected: |
| //======================================================================= |
| // implementation |
| //======================================================================= |
| /** |
| * This method is the actual implementation of the next() method. All iteration |
| * vectors through here. This method initializes the state machine to state 1 |
| * and advances through the text character by character until we reach the end |
| * of the text or the state machine transitions to state 0. We update our return |
| * value every time the state machine passes through a possible end state. |
| */ |
| virtual int32_t handleNext(void); |
| |
| /** |
| * This method backs the iterator back up to a "safe position" in the text. |
| * This is a position that we know, without any context, must be a break position. |
| * The various calling methods then iterate forward from this safe position to |
| * the appropriate position to return. (For more information, see the description |
| * of buildBackwardsStateTable() in RuleBasedBreakIterator.Builder.) |
| */ |
| virtual int32_t handlePrevious(void); |
| |
| /** |
| * Dumps caches and performs other actions associated with a complete change |
| * in text or iteration position. This function is a no-op in RuleBasedBreakIterator, |
| * but subclasses can and do override it. |
| */ |
| virtual void reset(void); |
| |
| /** |
| * Return true if the category lookup for this char |
| * indicates that it is in the set of dictionary lookup chars. |
| * This function is intended for use by dictionary based break iterators. |
| * @return true if the category lookup for this char |
| * indicates that it is in the set of dictionary lookup chars. |
| */ |
| virtual UBool isDictionaryChar(UChar32); |
| |
| /** |
| * Common initialization function, used by constructors and bufferClone. |
| * (Also used by DictionaryBasedBreakIterator::createBufferClone().) |
| */ |
| void init(); |
| |
| }; |
| |
| |
| |
| |
| //---------------------------------------------------------------------------------- |
| // |
| // Inline Functions Definitions ... |
| // |
| //---------------------------------------------------------------------------------- |
| |
| inline UBool RuleBasedBreakIterator::operator!=(const BreakIterator& that) const { |
| return !operator==(that); |
| } |
| |
| inline UClassID RuleBasedBreakIterator::getDynamicClassID(void) const { |
| return RuleBasedBreakIterator::getStaticClassID(); |
| } |
| |
| inline UClassID RuleBasedBreakIterator::getStaticClassID(void) { |
| return (UClassID)(&fgClassID); |
| } |
| |
| |
| |
| U_NAMESPACE_END |
| |
| #endif |
