--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/fontservices/textshaperplugin/IcuSource/common/unicode/rbbi.h Tue Feb 02 02:02:46 2010 +0200
@@ -0,0 +1,599 @@
+/*
+***************************************************************************
+* Copyright (C) 1999-2005 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"
+
+/**
+ * \file
+ * \brief C++ API: Rule Based Break Iterator
+ */
+
+#if !UCONFIG_NO_BREAK_ITERATION
+
+#include "unicode/brkiter.h"
+#include "unicode/udata.h"
+#include "unicode/parseerr.h"
+
+
+struct UTrie;
+
+U_NAMESPACE_BEGIN
+
+/** @internal */
+struct RBBIDataHeader;
+class RuleBasedBreakIteratorTables;
+class BreakIterator;
+class RBBIDataWrapper;
+struct RBBIStateTable;
+
+
+
+/**
+ *
+ * A subclass of BreakIterator whose behavior is specified using a list of rules.
+ * <p>Instances of this class are most commonly created by the factory methods of
+ * BreakIterator::createWordInstance(), BreakIterator::createLineInstance(), etc.,
+ * and then used via the abstract API in class BreakIterator</p>
+ *
+ * <p>See the ICU User Guide for information on Break Iterator Rules.</p>
+ *
+ * <p>This class is not intended to be subclassed. (Class DictionaryBasedBreakIterator
+ * is a subclass, but that relationship is effectively internal to the ICU
+ * implementation. The subclassing interface to RulesBasedBreakIterator is
+ * not part of the ICU API, and may not remain stable.</p>
+ *
+ */
+class U_COMMON_API RuleBasedBreakIterator : public BreakIterator {
+
+protected:
+ /**
+ * The character iterator through which this BreakIterator accesses the text
+ * @internal
+ */
+ CharacterIterator* fText;
+
+ /**
+ * The rule data for this BreakIterator instance
+ * @internal
+ */
+ RBBIDataWrapper *fData;
+
+ /** Index of the Rule {tag} values for the most recent match.
+ * @internal
+ */
+ int32_t fLastRuleStatusIndex;
+
+ /**
+ * Rule tag value valid flag.
+ * Some iterator operations don't intrinsically set the correct tag value.
+ * This flag lets us lazily compute the value if we are ever asked for it.
+ * @internal
+ */
+ UBool fLastStatusIndexValid;
+
+ /**
+ * 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.
+ * @internal
+ */
+ uint32_t fDictionaryCharCount;
+
+ /**
+ * Debugging flag. Trace operation of state machine when true.
+ * @internal
+ */
+ static UBool fTrace;
+
+
+protected:
+ //=======================================================================
+ // constructors
+ //=======================================================================
+
+ /**
+ * 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
+ * free it when done.
+ * @internal
+ */
+ RuleBasedBreakIterator(RBBIDataHeader* data, UErrorCode &status);
+
+ /** @internal */
+ friend class RBBIRuleBuilder;
+ /** @internal */
+ 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 to.
+ * @stable ICU 2.2
+ */
+ 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
+ * @stable ICU 2.0
+ */
+ RuleBasedBreakIterator(const RuleBasedBreakIterator& that);
+
+ /**
+ * Construct a RuleBasedBreakIterator from a set of rules supplied as a string.
+ * @param rules The break rules to be used.
+ * @param parseError In the event of a syntax error in the rules, provides the location
+ * within the rules of the problem.
+ * @param status Information on any errors encountered.
+ * @stable ICU 2.2
+ */
+ RuleBasedBreakIterator( const UnicodeString &rules,
+ UParseError &parseError,
+ UErrorCode &status);
+
+
+ /**
+ * This constructor uses the udata interface to create a BreakIterator
+ * whose internal tables live in a memory-mapped file. "image" is an
+ * ICU UDataMemory handle for the pre-compiled break iterator tables.
+ * @param image handle to the memory image for the break iterator data.
+ * Ownership of the UDataMemory handle passes to the Break Iterator,
+ * which will be responsible for closing it when it is no longer needed.
+ * @param status Information on any errors encountered.
+ * @see udata_open
+ * @see #getBinaryRules
+ * @stable ICU 2.8
+ */
+ RuleBasedBreakIterator(UDataMemory* image, UErrorCode &status);
+
+ /**
+ * Destructor
+ * @stable ICU 2.0
+ */
+ 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
+ * @stable ICU 2.0
+ */
+ 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.
+ * @stable ICU 2.0
+ */
+ 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.
+ * @stable ICU 2.0
+ */
+ 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.
+ * clone() is thread safe. Multiple threads may simultaeneously
+ * clone the same source break iterator.
+ * @return a newly-constructed RuleBasedBreakIterator
+ * @stable ICU 2.0
+ */
+ virtual BreakIterator* clone() const;
+
+ /**
+ * Compute a hash code for this BreakIterator
+ * @return A hash code
+ * @stable ICU 2.0
+ */
+ virtual int32_t hashCode(void) const;
+
+ /**
+ * Returns the description used to create this iterator
+ * @return the description used to create this iterator
+ * @stable ICU 2.0
+ */
+ 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.
+ * @stable ICU 2.0
+ */
+ virtual const CharacterIterator& getText(void) const;
+
+
+ /**
+ * Get a UText for the text being analyzed.
+ * The returned UText is a shallow clone of the UText used internally
+ * by the break iterator implementation. It can safely be used to
+ * access the text without impacting any break iterator operations,
+ * but the underlying text itself must not be altered.
+ *
+ * @param fillIn A UText to be filled in. If NULL, a new UText will be
+ * allocated to hold the result.
+ * @param status receives any error codes.
+ * @return The current UText for this break iterator. If an input
+ * UText was provided, it will always be returned.
+ * @draft ICU 3.4
+ */
+ virtual UText *getUText(UText *fillIn, UErrorCode &status) 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!
+ * @stable ICU 2.0
+ */
+ 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.
+ * @stable ICU 2.0
+ */
+ virtual void setText(const UnicodeString& newText);
+
+ /**
+ * Reset the break iterator to operate over the text represented by
+ * the UText. The iterator position is reset to the start.
+ *
+ * This function makes a shallow clone of the supplied UText. This means
+ * that the caller is free to immediately close or otherwise reuse the
+ * Utext that was passed as a parameter, but that the underlying text itself
+ * must not be altered while being referenced by the break iterator.
+ *
+ * @param text The UText used to change the text.
+ * @param status Receives any error codes.
+ * @draft ICU 3.4
+ */
+ virtual void setText(UText *text, UErrorCode &status);
+
+ /**
+ * 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.
+ * @stable ICU 2.0
+ */
+ 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.
+ * @stable ICU 2.0
+ */
+ 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.
+ * @stable ICU 2.0
+ */
+ 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.
+ * @stable ICU 2.0
+ */
+ virtual int32_t next(void);
+
+ /**
+ * Moves the iterator backwards, to the last boundary preceding this one.
+ * @return The position of the last boundary position preceding this one.
+ * @stable ICU 2.0
+ */
+ 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.
+ * @stable ICU 2.0
+ */
+ 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.
+ * @stable ICU 2.0
+ */
+ 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.
+ * @stable ICU 2.0
+ */
+ virtual UBool isBoundary(int32_t offset);
+
+ /**
+ * Returns the current iteration position.
+ * @return The current iteration position.
+ * @stable ICU 2.0
+ */
+ virtual int32_t current(void) const;
+
+
+ /**
+ * Return the status tag from the break rule that determined the most recently
+ * returned break position. For break rules that do not specify a
+ * status, a default value of 0 is returned. If more than one break rule
+ * would cause a boundary to be located at some position in the text,
+ * the numerically largest of the applicable status values is returned.
+ * <p>
+ * Of the standard types of ICU break iterators, only word break and
+ * line break provide status values. The values are defined in
+ * the header file ubrk.h. For Word breaks, the status allows distinguishing between words
+ * that contain alphabetic letters, "words" that appear to be numbers,
+ * punctuation and spaces, words containing ideographic characters, and
+ * more. For Line Break, the status distinguishes between hard (mandatory) breaks
+ * and soft (potential) break positions.
+ * <p>
+ * <code>getRuleStatus()</code> can be called after obtaining a boundary
+ * position from <code>next()</code>, <code>previous()</code>, or
+ * any other break iterator functions that returns a boundary position.
+ * <p>
+ * When creating custom break rules, one is free to define whatever
+ * status values may be convenient for the application.
+ * <p>
+ * Note: this function is not thread safe. It should not have been
+ * declared const, and the const remains only for compatibility
+ * reasons. (The function is logically const, but not bit-wise const).
+ * <p>
+ * @return the status from the break rule that determined the most recently
+ * returned break position.
+ *
+ * @see UWordBreak
+ * @stable ICU 2.2
+ */
+ virtual int32_t getRuleStatus() const;
+
+ /**
+ * Get the status (tag) values from the break rule(s) that determined the most
+ * recently returned break position.
+ * <p>
+ * The returned status value(s) are stored into an array provided by the caller.
+ * The values are stored in sorted (ascending) order.
+ * If the capacity of the output array is insufficient to hold the data,
+ * the output will be truncated to the available length, and a
+ * U_BUFFER_OVERFLOW_ERROR will be signaled.
+ *
+ * @param fillInVec an array to be filled in with the status values.
+ * @param capacity the length of the supplied vector. A length of zero causes
+ * the function to return the number of status values, in the
+ * normal way, without attemtping to store any values.
+ * @param status receives error codes.
+ * @return The number of rule status values from rules that determined
+ * the most recent boundary returned by the break iterator.
+ * In the event of a U_BUFFER_OVERFLOW_ERROR, the return value
+ * is the total number of status values that were available,
+ * not the reduced number that were actually returned.
+ * @see getRuleStatus
+ * @draft ICU 3.0
+ */
+ virtual int32_t getRuleStatusVec(int32_t *fillInVec, int32_t capacity, UErrorCode &status);
+
+ /**
+ * 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.
+ * @stable ICU 2.0
+ */
+ 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.
+ * @stable ICU 2.0
+ */
+ static UClassID U_EXPORT2 getStaticClassID(void);
+
+ /*
+ * Create a clone (copy) of this break iterator in memory provided
+ * by the caller. The idea is to increase performance by avoiding
+ * a storage allocation. Use of this functoin is NOT RECOMMENDED.
+ * Performance gains are minimal, and correct buffer management is
+ * tricky. Use clone() instead.
+ *
+ * @param stackBuffer The pointer to the memory into which the cloned object
+ * should be placed. If NULL, allocate heap memory
+ * for the cloned object.
+ * @param BufferSize The size of the buffer. If zero, return the required
+ * buffer size, but do not clone the object. If the
+ * size was too small (but not zero), allocate heap
+ * storage for the cloned object.
+ *
+ * @param status Error status. U_SAFECLONE_ALLOCATED_WARNING will be
+ * returned if the the provided buffer was too small, and
+ * the clone was therefore put on the heap.
+ *
+ * @return Pointer to the clone object. This may differ from the stackBuffer
+ * address if the byte alignment of the stack buffer was not suitable
+ * or if the stackBuffer was too small to hold the clone.
+ * @stable ICU 2.0
+ */
+ 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 from pre-compiled rules
+ * is much faster than building one from the source form of the
+ * break rules.
+ *
+ * The binary data can only be used with the same version of ICU
+ * and on the same platform type (processor endian-ness)
+ *
+ * @param length Returns the length of the binary data. (Out paramter.)
+ *
+ * @return A pointer to the binary (compiled) rule data. The storage
+ * belongs to the RulesBasedBreakIterator object, not the
+ * caller, and must not be modified or deleted.
+ * @internal
+ */
+ virtual const uint8_t *getBinaryRules(uint32_t &length);
+
+
+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.
+ * @internal
+ */
+ 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.)
+ * @internal
+ */
+ 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.
+ * @internal
+ */
+ 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.
+ * @internal
+ */
+ virtual UBool isDictionaryChar(UChar32);
+
+ /**
+ * Common initialization function, used by constructors and bufferClone.
+ * (Also used by DictionaryBasedBreakIterator::createBufferClone().)
+ * @internal
+ */
+ void init();
+
+private:
+
+ /**
+ * 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.)
+ * @param statetable state table used of moving backwards
+ * @internal
+ */
+ int32_t handlePrevious(const RBBIStateTable *statetable);
+
+ /**
+ * 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.
+ * @param statetable state table used of moving forwards
+ * @internal
+ */
+ int32_t handleNext(const RBBIStateTable *statetable);
+
+ /**
+ * @internal
+ */
+ void makeRuleStatusValid();
+
+};
+
+//------------------------------------------------------------------------------
+//
+// Inline Functions Definitions ...
+//
+//------------------------------------------------------------------------------
+
+inline UBool RuleBasedBreakIterator::operator!=(const BreakIterator& that) const {
+ return !operator==(that);
+}
+
+U_NAMESPACE_END
+
+#endif /* #if !UCONFIG_NO_BREAK_ITERATION */
+
+#endif