2094 lines
89 KiB
C++
2094 lines
89 KiB
C++
/*
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**********************************************************************
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* Copyright (C) 1999 International Business Machines Corporation *
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* and others. All rights reserved. *
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**********************************************************************
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* Date Name Description
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* 12/9/99 rgillam Ported from Java
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**********************************************************************
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*/
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#include "unicode\rbbi.h"
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#include "rbbi_bld.h"
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#include "cmemory.h"
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#include "unicode\unicode.h"
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//=======================================================================
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// RuleBasedBreakIterator.Builder
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//=======================================================================
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/**
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* The Builder class has the job of constructing a RuleBasedBreakIterator from a
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* textual description. A Builder is constructed by RuleBasedBreakIterator's
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* constructor, which uses it to construct the iterator itself and then throws it
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* away.
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* <p>The construction logic is separated out into its own class for two primary
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* reasons:
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* <ul><li>The construction logic is quite complicated and large. Separating it
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* out into its own class means the code must only be loaded into memory while a
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* RuleBasedBreakIterator is being constructed, and can be purged after that.
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* <li>There is a fair amount of state that must be maintained throughout the
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* construction process that is not needed by the iterator after construction.
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* Separating this state out into another class prevents all of the functions that
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* construct the iterator from having to have really long parameter lists,
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* (hopefully) contributing to readability and maintainability.</ul>
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* <p>It'd be really nice if this could be an independent class rather than an
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* inner class, because that would shorten the source file considerably, but
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* making Builder an inner class of RuleBasedBreakIterator allows it direct access
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* to RuleBasedBreakIterator's private members, which saves us from having to
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* provide some kind of "back door" to the Builder class that could then also be
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* used by other classes.
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*/
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const int32_t
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RuleBasedBreakIteratorBuilder::END_STATE_FLAG = 0x8000;
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const int32_t
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RuleBasedBreakIteratorBuilder::DONT_LOOP_FLAG = 0x4000;
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const int32_t
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RuleBasedBreakIteratorBuilder::LOOKAHEAD_STATE_FLAG = 0x2000;
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const int32_t
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RuleBasedBreakIteratorBuilder::ALL_FLAGS = END_STATE_FLAG
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| DONT_LOOP_FLAG | LOOKAHEAD_STATE_FLAG;
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// constants for various characters
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const UChar NULL_CHAR = 0x0000;
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const UChar OPEN_PAREN = 0x28;
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const UChar CLOSE_PAREN = 0x29;
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const UChar OPEN_BRACKET = 0x5b;
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const UChar CLOSE_BRACKET = 0x5d;
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const UChar OPEN_BRACE = 0x7b;
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const UChar CLOSE_BRACE = 0x7d;
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const UChar SEMICOLON = 0x3b;
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const UChar EQUAL_SIGN = 0x3d;
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const UChar MINUS = 0x2d;
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const UChar CARET = 0x5e;
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const UChar AMPERSAND = 0x26;
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const UChar COLON = 0x3a;
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const UChar ASTERISK = 0x2a;
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const UChar PLUS = 0x2b;
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const UChar QUESTION = 0x3f;
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const UChar PERIOD = 0x2e;
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const UChar PIPE = 0x7c;
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const UChar BANG = 0x21;
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const UChar SLASH = 0x2f;
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const UChar BACKSLASH = 0x5c;
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const UChar ASCII_LOW = 0x20;
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const UChar ASCII_HI = 0x7f;
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const UnicodeString IGNORE_NAME = UnicodeString("$ignore");
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//============================================================================
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/**
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* This class is a completely non-general quick-and-dirty class to make up
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* for the fact that at the time of this writing (12/20/99) there was no
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* general hash table class in the ICU. When one is created, this class should
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* be removed and the code that depends on this class should be altered to use
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* the regular hash-table class. This class is just here as a temporary measure
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* until that happens. --rtg 12/20/99
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*/
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class ExpressionList {
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private:
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UVector keys;
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UVector sets;
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UVector strings;
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public:
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static const UnicodeSet setNotThere; // an empty UnicodeSet we can use as a return value
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// in get() when the key isn't found
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static const UnicodeString stringNotThere;
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ExpressionList();
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~ExpressionList();
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const UnicodeSet& getSet(const UnicodeString& key) const;
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void putSet(const UnicodeString& key, UnicodeSet* valueToAdopt);
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const UnicodeString& getString(const UnicodeString& key) const;
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void putString(const UnicodeString& key, UnicodeString* valueToAdopt);
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const UnicodeString& getKeyAt(int32_t x) const { return *((UnicodeString*)keys[x]); }
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const UnicodeSet& operator[](int32_t x) const { return *((UnicodeSet*)sets[x]); }
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int32_t size() const { return keys.size(); }
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};
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const UnicodeSet
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ExpressionList::setNotThere;
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const UnicodeString
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ExpressionList::stringNotThere;
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ExpressionList::ExpressionList()
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{
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}
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ExpressionList::~ExpressionList()
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{
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for (int32_t i = 0; i < keys.size(); i++) {
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delete (UnicodeString*)keys[i];
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delete (UnicodeSet*)sets[i];
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delete (UnicodeString*)strings[i];
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}
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}
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const UnicodeSet&
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ExpressionList::getSet(const UnicodeString& key) const
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{
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for (int32_t i = 0; i < keys.size(); i++) {
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if (key == *((UnicodeString*)keys[i])) {
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return *((UnicodeSet*)sets[i]);
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}
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}
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return setNotThere;
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}
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void
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ExpressionList::putSet(const UnicodeString& key, UnicodeSet* valueToAdopt)
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{
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const UnicodeSet& theSet = getSet(key);
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if (&theSet != &setNotThere) {
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UnicodeSet* value = (UnicodeSet*)(&theSet);
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value->clear();
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value->addAll(*valueToAdopt);
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delete valueToAdopt;
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}
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else {
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keys.addElement(new UnicodeString(key));
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sets.addElement(valueToAdopt);
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strings.addElement(new UnicodeString);
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}
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}
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const UnicodeString&
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ExpressionList::getString(const UnicodeString& key) const
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{
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for (int32_t i = 0; i < keys.size(); i++) {
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if (key == *((UnicodeString*)keys[i])) {
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return *((UnicodeString*)strings[i]);
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}
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}
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return stringNotThere;
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}
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void
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ExpressionList::putString(const UnicodeString& key, UnicodeString* valueToAdopt)
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{
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const UnicodeString& theString = getString(key);
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if (&theString != &stringNotThere) {
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UnicodeString* value = (UnicodeString*)(&theString);
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*value = *valueToAdopt;
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delete valueToAdopt;
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}
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else {
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keys.addElement(new UnicodeString(key));
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sets.addElement(new UnicodeSet);
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strings.addElement(valueToAdopt);
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}
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}
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//============================================================================
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#define error(message, position, context) \
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setUpErrorMessage(message, position, context); \
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err = U_PARSE_ERROR; \
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return
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void
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stringDeleter(void* o) {
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delete (UnicodeString*)o;
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}
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void
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usetDeleter(void* o) {
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delete (UnicodeSet*)o;
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}
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void
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tableRowDeleter(void* o) {
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delete [] (int16_t*)o;
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}
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void
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vectorDeleter(void* o) {
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delete (UVector*)o;
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}
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void
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mergeRowDeleter(void* o) {
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delete [] (int32_t*)o;
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}
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/**
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* No special construction is required for the Builder.
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*/
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RuleBasedBreakIteratorBuilder::RuleBasedBreakIteratorBuilder(
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RuleBasedBreakIterator& iteratorToBuild)
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: iterator(iteratorToBuild),
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tables(new RuleBasedBreakIteratorTables)
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{
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iterator.tables = tables;
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tempRuleList.setDeleter(&stringDeleter);
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categories.setDeleter(&usetDeleter);
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tempStateTable.setDeleter(&tableRowDeleter);
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decisionPointStack.setDeleter(&vectorDeleter);
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// decisionPointList, loopingStates, and statesToBackfill (as well as the
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// individual elements in decisionPointStack) don't need deleters--
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// their element type is int32_t
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mergeList.setDeleter(&mergeRowDeleter);
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}
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RuleBasedBreakIteratorBuilder::~RuleBasedBreakIteratorBuilder()
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{
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delete expressions;
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}
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/**
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* This is the main function for setting up the BreakIterator's tables. It
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* just vectors different parts of the job off to other functions.
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*/
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void
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RuleBasedBreakIteratorBuilder::buildBreakIterator(const UnicodeString& description,
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UErrorCode& err)
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{
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if (U_FAILURE(err))
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return;
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UnicodeString tempDesc(description);
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buildRuleList(tempDesc, err);
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buildCharCategories(err);
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buildStateTable(err);
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buildBackwardsStateTable(err);
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}
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/**
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* Thus function has three main purposes:
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* <ul><li>Perform general syntax checking on the description, so the rest of the
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* build code can assume that it's parsing a legal description.
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* <li>Split the description into separate rules
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* <li>Perform variable-name substitutions (so that no one else sees variable names)
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* </ul>
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*/
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void
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RuleBasedBreakIteratorBuilder::buildRuleList(UnicodeString& description,
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UErrorCode& err)
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{
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if (U_FAILURE(err))
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return;
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// invariants:
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// - parentheses must be balanced: ()[]{}
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// - nothing can be nested inside {}
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// - nothing can be nested inside [] except more []s
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// - pairs of ()[]{} must not be empty
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// - ; can only occur at the outer level
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// - | can only appear inside ()
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// - only one = or / can occur in a single rule
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// - = and / cannot both occur in the same rule
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// - the right-hand side of a = expression must be enclosed in [] or ()
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// - *. ?, and + may not occur at the beginning of a rule, nor may they follow
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// =, /, (, (, |, }, ;, +, ?, or * (except that ? can follow *)
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// - the rule list must contain at least one / rule (which may or may not
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// actually contain a /
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// - no rule may be empty
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// - all printing characters in the ASCII range except letters and digits
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// are reserved and must be preceded by \
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// - ! may only occur at the beginning of a rule
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// set up a vector to contain the broken-up description (each entry in the
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// vector is a separate rule) and a stack for keeping track of opening
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// punctuation
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UStack parenStack;
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UTextOffset p = 0;
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UTextOffset ruleStart = 0;
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UChar c = 0x0000;
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UChar lastC = 0x0000;
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UChar lastOpen = 0x0000;
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UBool haveEquals = FALSE;
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UBool haveSlash = FALSE;
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UBool sawVarName = FALSE;
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UBool sawIllegalChar = FALSE;
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int32_t illegalCharPos = 0;
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UChar expectedClose = 0x0000;
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// if the description doesn't end with a semicolon, tack a semicolon onto the end
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if (description.length() != 0 && description[description.length() - 1] != SEMICOLON) {
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description += SEMICOLON;
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}
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// for each character, do...
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while (p < description.length()) {
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c = description[p];
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switch (c) {
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// if the character is opening punctuation, verify that no nesting
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// rules are broken, and push the character onto the stack
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case OPEN_BRACE:
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case OPEN_BRACKET:
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case OPEN_PAREN:
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if (lastOpen == OPEN_BRACE) {
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error("Can't nest brackets inside {}", p, description);
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}
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if (lastOpen == OPEN_BRACKET && c != OPEN_BRACKET) {
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error("Can't nest anything in [] but []", p, description);
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}
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// if we see { anywhere except on the left-hand side of =,
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// we must be seeing a variable name that was never defined
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if (c == OPEN_BRACE && (haveEquals || haveSlash)) {
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error("Unknown variable name", p, description);
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}
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lastOpen = c;
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parenStack.push((void*)c);
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if (c == OPEN_BRACE) {
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sawVarName = TRUE;
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}
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break;
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// if the character is closing punctuation, verify that it matches the
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// last opening punctuation we saw, and that the brackets contain
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// something, then pop the stack
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case CLOSE_BRACE:
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case CLOSE_BRACKET:
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case CLOSE_PAREN:
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expectedClose = NULL_CHAR;
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switch (lastOpen) {
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case OPEN_BRACE:
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expectedClose = CLOSE_BRACE;
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break;
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case OPEN_BRACKET:
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expectedClose = CLOSE_BRACKET;
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break;
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case OPEN_PAREN:
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expectedClose = CLOSE_PAREN;
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break;
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}
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if (c != expectedClose) {
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error("Unbalanced parentheses", p, description);
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}
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if (lastC == lastOpen) {
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error("Parens don't contain anything", p, description);
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}
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parenStack.pop();
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if (!parenStack.empty()) {
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lastOpen = (UChar)(int32_t)parenStack.peek();
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}
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else {
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lastOpen = NULL_CHAR;
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}
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break;
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// if the character is an asterisk, make sure it occurs in a place
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// where an asterisk can legally go
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case ASTERISK:
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case PLUS:
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case QUESTION:
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switch (lastC) {
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case EQUAL_SIGN: case SLASH: case OPEN_PAREN: case PIPE:
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case ASTERISK: case PLUS: case QUESTION: case SEMICOLON:
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case NULL_CHAR:
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error("Misplaced *, +, or ?", p, description);
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default:
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break;
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}
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break;
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// if the character is an equals sign, make sure we haven't seen another
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// equals sign or a slash yet
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case EQUAL_SIGN:
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if (haveEquals || haveSlash) {
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error("More than one = or / in rule", p, description);
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}
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haveEquals = TRUE;
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sawIllegalChar = FALSE;
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break;
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// if the character is a slash, make sure we haven't seen another slash
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// or an equals sign yet
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case SLASH:
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if (haveEquals || haveSlash) {
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error("More than one = or / in rule", p, description);
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}
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if (sawVarName) {
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error("Unknown variable name", p, description);
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}
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haveSlash = TRUE;
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break;
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// if the character is an exclamation point, make sure it occurs only
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// at the beginning of a rule
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case BANG:
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if (lastC != SEMICOLON && lastC != NULL_CHAR) {
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error("! can only occur at the beginning of a rule", p, description);
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}
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break;
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// if the character is a backslash, skip the character that follows it
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// (it'll get treated as a literal character)
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case BACKSLASH:
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++p;
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break;
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// we don't have to do anything special on a period
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case PERIOD:
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break;
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// if the character is a syntax character that can only occur
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// inside [], make sure that it does in fact only occur inside []
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// (or in a variable name)
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case CARET:
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case MINUS:
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case COLON:
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case AMPERSAND:
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if (lastOpen != OPEN_BRACKET && lastOpen != OPEN_BRACE && !sawIllegalChar) {
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sawIllegalChar = TRUE;
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illegalCharPos = p;
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}
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break;
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// if the character is a semicolon, do the following...
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case SEMICOLON:
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// if we saw any illegal characters along the way, throw
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// an error
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if (sawIllegalChar) {
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error("Illegal character", illegalCharPos, description);
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}
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// make sure the rule contains something and that there are no
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// unbalanced parentheses or brackets
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if (lastC == SEMICOLON || lastC == NULL_CHAR) {
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error("Empty rule", p, description);
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}
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if (!parenStack.empty()) {
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error("Unbalanced parenheses", p, description);
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}
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if (parenStack.empty()) {
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// if the rule contained an = sign, call processSubstitution()
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// to replace the substitution name with the substitution text
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// wherever it appears in the description
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if (haveEquals) {
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processSubstitution(description, ruleStart, p + 1, p + 1, err);
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}
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else {
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// otherwise, check to make sure the rule doesn't reference
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// any undefined substitutions
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if (sawVarName) {
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error("Unknown variable name", p, description);
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}
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// then add it to tempRuleList
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UnicodeString* newRule = new UnicodeString();
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description.extractBetween(ruleStart, p, *newRule);
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tempRuleList.addElement(newRule);
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}
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// and reset everything to process the next rule
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ruleStart = p + 1;
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haveEquals = haveSlash = sawVarName = sawIllegalChar = FALSE;
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}
|
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break;
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|
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// if the character is a vertical bar, check to make sure that it
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// occurs inside a () expression and that the character that precedes
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// it isn't also a vertical bar
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case PIPE:
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if (lastC == PIPE) {
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error("Empty alternative", p, description);
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}
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if (parenStack.empty() || lastOpen != OPEN_PAREN) {
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error("Misplaced |", p, description);
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}
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break;
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|
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// if the character is anything else (escaped characters are
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// skipped and don't make it here), it's an error
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default:
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if (c >= ASCII_LOW && c < ASCII_HI && !Unicode::isLetter(c)
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&& !Unicode::isDigit(c) && !sawIllegalChar) {
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sawIllegalChar = TRUE;
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illegalCharPos = p;
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}
|
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break;
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}
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lastC = c;
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++p;
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}
|
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if (tempRuleList.size() == 0) {
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error("No valid rules in description", p, description);
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}
|
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}
|
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|
|
/**
|
|
* This function performs variable-name substitutions. First it does syntax
|
|
* checking on the variable-name definition. If it's syntactically valid, it
|
|
* then goes through the remainder of the description and does a simple
|
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* find-and-replace of the variable name with its text. (The variable text
|
|
* must be enclosed in either [] or () for this to work.)
|
|
*/
|
|
void
|
|
RuleBasedBreakIteratorBuilder::processSubstitution(UnicodeString& description,
|
|
UTextOffset ruleStart,
|
|
UTextOffset ruleEnd,
|
|
UTextOffset startPos,
|
|
UErrorCode& err)
|
|
{
|
|
if (U_FAILURE(err))
|
|
return;
|
|
|
|
// isolate out the text on either side of the equals sign
|
|
UnicodeString substitutionRule;
|
|
UnicodeString replace;
|
|
UnicodeString replaceWith;
|
|
|
|
description.extractBetween(ruleStart, ruleEnd, substitutionRule);
|
|
UTextOffset equalPos = substitutionRule.indexOf(EQUAL_SIGN);
|
|
substitutionRule.extractBetween(0, equalPos, replace);
|
|
substitutionRule.extractBetween(equalPos + 1, substitutionRule.length() - 1, replaceWith);
|
|
|
|
// check to see whether the substitution name is something we've declared
|
|
// to be "special". For RuleBasedBreakIterator itself, this is "$ignore".
|
|
// This function takes care of any extra processing that has to be done
|
|
// with "special" substitution names.
|
|
handleSpecialSubstitution(replace, replaceWith, startPos, description, err);
|
|
|
|
// perform various other syntax checks on the rule
|
|
if (replaceWith.length() == 0) {
|
|
error("Nothing on right-hand side of =", startPos, description);
|
|
}
|
|
if (replace.length() == 0) {
|
|
error("Nothing on left-hand side of =", startPos, description);
|
|
}
|
|
if (!(replaceWith[0] == OPEN_BRACKET
|
|
&& replaceWith[replaceWith.length() - 1] == CLOSE_BRACKET)
|
|
&& !(replaceWith[0] == OPEN_PAREN
|
|
&& replaceWith[replaceWith.length() - 1] == CLOSE_PAREN)) {
|
|
error("Illegal right-hand side for =", startPos, description);
|
|
}
|
|
|
|
// now go through the rest of the description (which hasn't been broken up
|
|
// into separate rules yet) and replace every occurrence of the
|
|
// substitution name with the substitution body
|
|
if (replace[0] != OPEN_BRACE) {
|
|
replace.insert(0, OPEN_BRACE);
|
|
replace += CLOSE_BRACE;
|
|
}
|
|
|
|
description.removeBetween(ruleStart, ruleEnd);
|
|
|
|
UTextOffset lastPos = startPos;
|
|
UTextOffset pos = description.indexOf(replace, lastPos);
|
|
while (pos != -1) {
|
|
description.replaceBetween(pos, pos + replace.length(), replaceWith);
|
|
lastPos = pos + replace.length();
|
|
pos = description.indexOf(replace, lastPos);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* This function defines a protocol for handling substitution names that
|
|
* are "special," i.e., that have some property beyond just being
|
|
* substitutions. At the RuleBasedBreakIterator level, we have one
|
|
* special substitution name, "$ignore". Subclasses can override this
|
|
* function to add more. Any special processing that has to go on beyond
|
|
* that which is done by the normal substitution-processing code is done
|
|
* here.
|
|
*/
|
|
void
|
|
RuleBasedBreakIteratorBuilder::handleSpecialSubstitution(const UnicodeString& replace,
|
|
const UnicodeString& replaceWith,
|
|
int32_t startPos,
|
|
const UnicodeString& description,
|
|
UErrorCode& err)
|
|
{
|
|
if (U_FAILURE(err))
|
|
return;
|
|
|
|
// if we get a definition for a substitution called "$ignore", it defines
|
|
// the ignore characters for the iterator. Check to make sure the expression
|
|
// is a [] expression, and if it is, parse it and store the characters off
|
|
// to the side.
|
|
if (replace == IGNORE_NAME) {
|
|
if (replaceWith.charAt(0) == OPEN_PAREN) {
|
|
error("Ignore group can't be enclosed in (", startPos, description);
|
|
}
|
|
ignoreChars = UnicodeSet(replaceWith, err);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* This function provides a hook for subclasses to mess with the character
|
|
* category table.
|
|
*/
|
|
void
|
|
RuleBasedBreakIteratorBuilder::mungeExpressionList()
|
|
{
|
|
// base class doesn't do anything-- this is here
|
|
// for subclasses
|
|
}
|
|
|
|
/**
|
|
* This function builds the character category table. On entry,
|
|
* tempRuleList is a vector of break rules that has had variable names substituted.
|
|
* On exit, the charCategoryTable data member has been initialized to hold the
|
|
* character category table, and tempRuleList's rules have been munged to contain
|
|
* character category numbers everywhere a literal character or a [] expression
|
|
* originally occurred.
|
|
*/
|
|
void
|
|
RuleBasedBreakIteratorBuilder::buildCharCategories(UErrorCode& err)
|
|
{
|
|
if (U_FAILURE(err))
|
|
return;
|
|
|
|
int32_t bracketLevel = 0;
|
|
UTextOffset p = 0;
|
|
int32_t lineNum = 0;
|
|
|
|
// build hash table of every literal character or [] expression in the rule list
|
|
// and derive a UnicodeSet object representing the characters each refers to
|
|
while (lineNum < tempRuleList.size()) {
|
|
UnicodeString* line = (UnicodeString*)(tempRuleList[lineNum]);
|
|
p = 0;
|
|
while (p < line->length()) {
|
|
UChar c = (*line)[p];
|
|
switch (c) {
|
|
// skip over all syntax characters except [
|
|
case OPEN_PAREN: case CLOSE_PAREN: case ASTERISK: case PERIOD: case SLASH:
|
|
case PIPE: case SEMICOLON: case QUESTION: case BANG: case PLUS:
|
|
break;
|
|
|
|
// for [, find the matching ] (taking nested [] pairs into account)
|
|
// and add the whole expression to the expression list
|
|
case OPEN_BRACKET:
|
|
{
|
|
UTextOffset q = p + 1;
|
|
++bracketLevel;
|
|
while (q < line->length() && bracketLevel != 0) {
|
|
c = (*line)[q];
|
|
if (c == OPEN_BRACKET) {
|
|
++bracketLevel;
|
|
}
|
|
else if (c == CLOSE_BRACKET) {
|
|
--bracketLevel;
|
|
}
|
|
++q;
|
|
}
|
|
|
|
UnicodeString temp;
|
|
line->extractBetween(p, q, temp);
|
|
if (&expressions->getSet(temp) == &ExpressionList::setNotThere) {
|
|
expressions->putSet(temp, new UnicodeSet(temp, err));
|
|
}
|
|
p = q - 1;
|
|
}
|
|
break;
|
|
|
|
// for \ sequences, just move to the next character and treat
|
|
// it as a single character
|
|
case BACKSLASH:
|
|
++p;
|
|
c = (*line)[p];
|
|
// DON'T break; fall through into "default" clause
|
|
|
|
// for an isolated single character, add it to the expression list
|
|
default:
|
|
{
|
|
UnicodeString temp;
|
|
|
|
line->extractBetween(p, p + 1, temp);
|
|
expressions->putSet(temp, new UnicodeSet(temp, err));
|
|
}
|
|
break;
|
|
}
|
|
++p;
|
|
}
|
|
++lineNum;
|
|
}
|
|
|
|
// create the temporary category table (which is a vector of UnicodeSet objects)
|
|
if (ignoreChars.isEmpty()) {
|
|
categories.addElement(new UnicodeSet(ignoreChars));
|
|
}
|
|
else {
|
|
categories.addElement(new UnicodeSet());
|
|
}
|
|
ignoreChars.clear();
|
|
|
|
// this is a hook to allow subclasses to add categories on their own
|
|
mungeExpressionList();
|
|
|
|
// Derive the character categories. Go through the existing character categories
|
|
// looking for overlap. Any time there's overlap, we create a new character
|
|
// category for the characters that overlapped and remove them from their original
|
|
// category. At the end, any characters that are left in the expression haven't
|
|
// been mentioned in any category, so another new category is created for them.
|
|
// For example, if the first expression is [abc], then a, b, and c will be placed
|
|
// into a single character category. If the next expression is [bcd], we will first
|
|
// remove b and c from their existing category (leaving a behind), create a new
|
|
// category for b and c, and then create another new category for d (which hadn't
|
|
// been mentioned in the previous expression).
|
|
// At no time should a character ever occur in more than one character category.
|
|
|
|
// for each expression in the expressions list, do...
|
|
for (int32_t i = 0; i < expressions->size(); i++) {
|
|
// initialize the working char set to the chars in the current expression
|
|
UnicodeSet e = UnicodeSet((*expressions)[i]);
|
|
|
|
// for each category in the category list, do...
|
|
for (int32_t j = categories.size() - 1; !e.isEmpty() && j > 0; j--) {
|
|
|
|
// if there's overlap between the current working set of chars
|
|
// and the current category...
|
|
UnicodeSet* that = (UnicodeSet*)(categories[j]);
|
|
UnicodeSet temp = UnicodeSet(e);
|
|
temp.retainAll(*that);
|
|
if (!temp.isEmpty()) {
|
|
// if the current category is not a subset of the current
|
|
// working set of characters, then remove the overlapping
|
|
// characters from the current category and create a new
|
|
// category for them
|
|
if (temp != *that) {
|
|
that->removeAll(temp);
|
|
categories.addElement(new UnicodeSet(temp));
|
|
}
|
|
|
|
// and always remove the overlapping characters from the current
|
|
// working set of characters
|
|
e.removeAll(temp);
|
|
}
|
|
}
|
|
|
|
// if there are still characters left in the working char set,
|
|
// add a new category containing them
|
|
if (!e.isEmpty()) {
|
|
categories.addElement(new UnicodeSet(e));
|
|
}
|
|
}
|
|
|
|
// we have the ignore characters stored in position 0. Make an extra pass through
|
|
// the character category list and remove anything from the ignore list that shows
|
|
// up in some other category
|
|
UnicodeSet allChars;
|
|
for (int32_t i = 1; i < categories.size(); i++)
|
|
allChars.addAll(*(UnicodeSet*)(categories[i]));
|
|
UnicodeSet* ignoreChars = (UnicodeSet*)(categories[0]);
|
|
ignoreChars->removeAll(allChars);
|
|
|
|
// now that we've derived the character categories, go back through the expression
|
|
// list and replace each UnicodeSet object with a String that represents the
|
|
// character categories that expression refers to. The String is encoded: each
|
|
// character is a character category number (plus 0x100 to avoid confusing them
|
|
// with syntax characters in the rule grammar)
|
|
for (int32_t i = 0; i < expressions->size(); i++) {
|
|
const UnicodeSet& cs = (*expressions)[i];
|
|
UnicodeString* cats = new UnicodeString;
|
|
|
|
// for each category...
|
|
for (int32_t j = 1; j < categories.size(); j++) {
|
|
|
|
// if the current expression contains characters in that category...
|
|
if (cs.containsAll(*(UnicodeSet*)(categories[j]))) {
|
|
|
|
// then add the encoded category number to the String for this
|
|
// expression
|
|
*cats += (UChar)(0x100 + j);
|
|
if (cs == *(UnicodeSet*)(categories[j])) {
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
// once we've finished building the encoded String for this expression,
|
|
// replace the UnicodeSet object with it
|
|
expressions->putString(expressions->getKeyAt(i), cats);
|
|
}
|
|
|
|
// and finally, we turn the temporary category table into a permanent category
|
|
// table, which is a CompactByteArray. (we skip category 0, which by definition
|
|
// refers to all characters not mentioned specifically in the rules)
|
|
tables->charCategoryTable = ucmp8_open((int8_t)0);
|
|
|
|
// for each category...
|
|
for (int32_t i = 0; i < categories.size(); i++) {
|
|
UnicodeSet& chars = *(UnicodeSet*)(categories[i]);
|
|
const UnicodeString& pairs = chars.getPairs();
|
|
|
|
// go through the character ranges in the category one by one...
|
|
for (int32_t j = 0; j < pairs.length(); j += 2) {
|
|
// and set the corresponding elements in the CompactArray accordingly
|
|
if (i != 0) {
|
|
ucmp8_setRange(tables->charCategoryTable, pairs[j], pairs[j + 1],
|
|
(int8_t)i);
|
|
}
|
|
|
|
// (category 0 is special-- it's the hiding place for the ignore
|
|
// characters, whose real category number in the CompactArray is
|
|
// -1 [this is because category 0 contains all characters not
|
|
// specifically mentioned anywhere in the rules] )
|
|
else {
|
|
ucmp8_setRange(tables->charCategoryTable, pairs[j], pairs[j + 1],
|
|
RuleBasedBreakIterator::IGNORE);
|
|
}
|
|
}
|
|
}
|
|
|
|
// once we've populated the CompactArray, compact it
|
|
ucmp8_compact(tables->charCategoryTable, 32);
|
|
|
|
// initialize numCategories
|
|
numCategories = categories.size();
|
|
tables->numCategories = numCategories;
|
|
}
|
|
|
|
/**
|
|
* This is the function that builds the forward state table. Most of the real
|
|
* work is done in parseRule(), which is called once for each rule in the
|
|
* description.
|
|
*/
|
|
void
|
|
RuleBasedBreakIteratorBuilder::buildStateTable(UErrorCode& err)
|
|
{
|
|
if (U_FAILURE(err))
|
|
return;
|
|
|
|
// initialize our temporary state table, and fill it with two states:
|
|
// state 0 is a dummy state that allows state 1 to be the starting state
|
|
// and 0 to represent "stop". State 1 is added here to seed things
|
|
// before we start parsing
|
|
tempStateTable.addElement(new int16_t[tables->numCategories + 1]);
|
|
tempStateTable.addElement(new int16_t[tables->numCategories + 1]);
|
|
|
|
// call parseRule() for every rule in the rule list (except those which
|
|
// start with !, which are actually backwards-iteration rules)
|
|
for (int32_t i = 0; i < tempRuleList.size(); i++) {
|
|
UnicodeString* rule = (UnicodeString*)tempRuleList[i];
|
|
if ((*rule)[0] != BANG) {
|
|
parseRule(*rule, TRUE);
|
|
}
|
|
}
|
|
|
|
// finally, use finishBuildingStateTable() to minimize the number of
|
|
// states in the table and perform some other cleanup work
|
|
finishBuildingStateTable(TRUE);
|
|
}
|
|
|
|
/**
|
|
* This is where most of the work really happens. This routine parses a single
|
|
* rule in the rule description, adding and modifying states in the state
|
|
* table according to the new expression. The state table is kept deterministic
|
|
* throughout the whole operation, although some ugly postprocessing is needed
|
|
* to handle the *? token.
|
|
*/
|
|
void
|
|
RuleBasedBreakIteratorBuilder::parseRule(const UnicodeString& rule,
|
|
UBool forward)
|
|
{
|
|
// algorithm notes:
|
|
// - The basic idea here is to read successive character-category groups
|
|
// from the input string. For each group, you create a state and point
|
|
// the appropriate entries in the previous state to it. This produces a
|
|
// straight line from the start state to the end state. The {}, *, and (|)
|
|
// idioms produce branches in this straight line. These branches (states
|
|
// that can transition to more than one other state) are called "decision
|
|
// points." A list of decision points is kept. This contains a list of
|
|
// all states that can transition to the next state to be created. For a
|
|
// straight line progression, the only thing in the decision-point list is
|
|
// the current state. But if there's a branch, the decision-point list
|
|
// will contain all of the beginning points of the branch when the next
|
|
// state to be created represents the end point of the branch. A stack is
|
|
// used to save decision point lists in the presence of nested parentheses
|
|
// and the like. For example, when a { is encountered, the current decision
|
|
// point list is saved on the stack and restored when the corresponding }
|
|
// is encountered. This way, after the } is read, the decision point list
|
|
// will contain both the state right before the } _and_ the state before
|
|
// the whole {} expression. Both of these states can transition to the next
|
|
// state after the {} expression.
|
|
// - one complication arises when we have to stamp a transition value into
|
|
// an array cell that already contains one. The updateStateTable() and
|
|
// mergeStates() functions handle this case. Their basic approach is to
|
|
// create a new state that combines the two states that conflict and point
|
|
// at it when necessary. This happens recursively, so if the merged states
|
|
// also conflict, they're resolved in the same way, and so on. There are
|
|
// a number of tests aimed at preventing infinite recursion.
|
|
// - another complication arises with repeating characters. It's somewhat
|
|
// ambiguous whether the user wants a greedy or non-greedy match in these cases.
|
|
// (e.g., whether "[a-z]*abc" means the SHORTEST sequence of letters ending in
|
|
// "abc" or the LONGEST sequence of letters ending in "abc". We've adopted
|
|
// the *? to mean "shortest" and * by itself to mean "longest". (You get the
|
|
// same result with both if there's no overlap between the repeating character
|
|
// group and the group immediately following it.) Handling the *? token is
|
|
// rather complicated and involves keeping track of whether a state needs to
|
|
// be merged (as described above) or merely overwritten when you update one of
|
|
// its cells, and copying the contents of a state that loops with a *? token
|
|
// into some of the states that follow it after the rest of the table-building
|
|
// process is complete ("backfilling").
|
|
// implementation notes:
|
|
// - This function assumes syntax checking has been performed on the input string
|
|
// prior to its being passed in here. It assumes that parentheses are
|
|
// balanced, all literal characters are enclosed in [] and turned into category
|
|
// numbers, that there are no illegal characters or character sequences, and so
|
|
// on. Violation of these invariants will lead to undefined behavior.
|
|
// - It'd probably be better to use linked lists rather than UVector and UStack
|
|
// to maintain the decision point list and stack. I went for simplicity in
|
|
// this initial implementation. If performance is critical enough, we can go
|
|
// back and fix this later.
|
|
// -There are a number of important limitations on the *? token. It does not work
|
|
// right when followed by a repeating character sequence (e.g., ".*?(abc)*")
|
|
// (although it does work right when followed by a single repeating character).
|
|
// It will not always work right when nested in parentheses or braces (although
|
|
// sometimes it will). It also will not work right if the group of repeating
|
|
// characters and the group of characters that follows overlap partially
|
|
// (e.g., "[a-g]*?[e-j]"). None of these capabilites was deemed necessary for
|
|
// describing breaking rules we know about, so we left them out for
|
|
// expeditiousness.
|
|
// - Rules such as "[a-z]*?abc;" will be treated the same as "[a-z]*?aa*bc;"--
|
|
// that is, if the string ends in "aaaabc", the break will go before the first
|
|
// "a" rather than the last one. Both of these are limitations in the design
|
|
// of RuleBasedBreakIterator and not limitations of the rule parser.
|
|
|
|
UTextOffset p = 0;
|
|
int32_t currentState = 1; // don't use state number 0; 0 means "stop"
|
|
int32_t lastState = currentState;
|
|
UnicodeString pendingChars;
|
|
UnicodeString temp;
|
|
|
|
int16_t* state;
|
|
UBool sawEarlyBreak = FALSE;
|
|
|
|
// if we're adding rules to the backward state table, mark the initial state
|
|
// as a looping state
|
|
if (!forward) {
|
|
loopingStates.addElement((void*)1);
|
|
}
|
|
|
|
// put the current state on the decision point list before we start
|
|
decisionPointList.addElement((void*)currentState); // we want currentState to
|
|
// be 1 here...
|
|
currentState = tempStateTable.size() - 1; // but after that, we want it to be
|
|
// 1 less than the state number of the next state
|
|
while (p < rule.length()) {
|
|
UChar c = rule[p];
|
|
clearLoopingStates = FALSE;
|
|
|
|
// this section handles literal characters, escaped characters (which are
|
|
// effectively literal characters too), the . token, and [] expressions
|
|
if (c == OPEN_BRACKET
|
|
|| c == BACKSLASH
|
|
|| Unicode::isLetter(c)
|
|
|| Unicode::isDigit(c)
|
|
|| c < ASCII_LOW
|
|
|| c == PERIOD
|
|
|| c >= ASCII_HI) {
|
|
|
|
// if we're not on a period, isolate the expression and look up
|
|
// the corresponding category list
|
|
if (c != PERIOD) {
|
|
UTextOffset q = p;
|
|
|
|
// if we're on a backslash, the expression is the character
|
|
// after the backslash
|
|
if (c == BACKSLASH) {
|
|
q = p + 2;
|
|
++p;
|
|
}
|
|
|
|
// if we're on an opening bracket, scan to the closing bracket
|
|
// to isolate the expression
|
|
else if (c == OPEN_BRACKET) {
|
|
int32_t bracketLevel = 1;
|
|
while (bracketLevel > 0) {
|
|
++q;
|
|
c = rule[q];
|
|
if (c == OPEN_BRACKET) {
|
|
++bracketLevel;
|
|
}
|
|
else if (c == CLOSE_BRACKET) {
|
|
--bracketLevel;
|
|
}
|
|
else if (c == BACKSLASH) {
|
|
++q;
|
|
}
|
|
}
|
|
++q;
|
|
}
|
|
|
|
// otherwise, the expression is just the character itself
|
|
else {
|
|
q = p + 1;
|
|
}
|
|
|
|
// look up the category list for the expression and store it
|
|
// in pendingChars
|
|
rule.extractBetween(p, q, temp);
|
|
pendingChars = expressions->getString(temp);
|
|
|
|
// advance the current position past the expression
|
|
p = q - 1;
|
|
}
|
|
|
|
// if the character we're on is a period, we end up down here
|
|
else {
|
|
int32_t rowNum = (int32_t)decisionPointList.lastElement();
|
|
state = (int16_t*)tempStateTable[rowNum];
|
|
|
|
// if the period is followed by an asterisk, then just set the current
|
|
// state to loop back on itself
|
|
if (p + 1 < rule.length() && rule[p + 1] == ASTERISK && state[0] != 0) {
|
|
decisionPointList.addElement((void*)state[0]);
|
|
pendingChars.remove();
|
|
++p;
|
|
if (p + 1 < rule.length() && rule[p + 1] == QUESTION) {
|
|
//System.out.println("Saw *?");
|
|
setLoopingStates(&decisionPointList, decisionPointList);
|
|
++p;
|
|
}
|
|
//System.out.println("Saw .*");
|
|
}
|
|
|
|
// otherwise, fabricate a category list ("pendingChars") with
|
|
// every category in it
|
|
else {
|
|
pendingChars.remove();
|
|
for (int32_t i = 0; i < numCategories; i++)
|
|
pendingChars += (UChar)(i + 0x100);
|
|
}
|
|
}
|
|
|
|
// we'll end up in here for all expressions except for .*, which is
|
|
// special-cased above
|
|
if (pendingChars.length() != 0) {
|
|
|
|
// if the expression is followed by an asterisk, then push a copy
|
|
// of the current decision point list onto the stack
|
|
if (p + 1 < rule.length() && (
|
|
rule[p + 1] == ASTERISK ||
|
|
rule[p + 1] == QUESTION
|
|
)) {
|
|
UVector* clone = new UVector;
|
|
for (int32_t i = 0; i < decisionPointList.size(); i++) {
|
|
clone->addElement(decisionPointList[i]);
|
|
// (there's no ownership issue here because the vector
|
|
// elements are all integers)
|
|
}
|
|
decisionPointStack.push(clone);
|
|
}
|
|
|
|
// create a new state, add it to the list of states to backfill
|
|
// if we have looping states to worry about, set its "don't make
|
|
// me an accepting state" flag if we've seen a slash, and add
|
|
// it to the end of the state table
|
|
int32_t newState = tempStateTable.size();
|
|
if (loopingStates.size() != 0) {
|
|
statesToBackfill.addElement((void*)newState);
|
|
}
|
|
state = new int16_t[numCategories + 1];
|
|
if (sawEarlyBreak) {
|
|
state[numCategories] = DONT_LOOP_FLAG;
|
|
}
|
|
tempStateTable.addElement(state);
|
|
|
|
// update everybody in the decision point list to point to
|
|
// the new state (this also performs all the reconciliation
|
|
// needed to make the table deterministic), then clear the
|
|
// decision point list
|
|
updateStateTable(decisionPointList, pendingChars, (int16_t)newState);
|
|
decisionPointList.removeAllElements();
|
|
|
|
// add all states created since the last literal character we've
|
|
// seen to the decision point list
|
|
lastState = currentState;
|
|
do {
|
|
++currentState;
|
|
decisionPointList.addElement((void*)currentState);
|
|
} while (currentState + 1 < tempStateTable.size());
|
|
}
|
|
}
|
|
|
|
// a * denotes a repeating character or group (* after () is handled separately
|
|
// below). In addition to restoring the decision point list, modify the
|
|
// current state to point to itself on the appropriate character categories.
|
|
if (c == PLUS || c == ASTERISK || c == QUESTION) {
|
|
// when there's a *, update the current state to loop back on itself
|
|
// on the character categories that caused us to enter this state
|
|
if (c == ASTERISK || c == PLUS) {
|
|
for (int32_t i = lastState + 1; i < tempStateTable.size(); i++) {
|
|
UVector temp2;
|
|
temp2.addElement((void*)i);
|
|
updateStateTable(temp2, pendingChars, (int16_t)(lastState + 1));
|
|
}
|
|
}
|
|
|
|
// pop the top element off the decision point stack and merge
|
|
// it with the current decision point list (this causes the divergent
|
|
// paths through the state table to come together again on the next
|
|
// new state)
|
|
if (c == ASTERISK || c == QUESTION) {
|
|
UVector* temp2 = (UVector*)decisionPointStack.pop();
|
|
for (int32_t i = 0; i < temp2->size(); i++)
|
|
decisionPointList.addElement((*temp2)[i]);
|
|
delete temp2;
|
|
|
|
// a ? after a * modifies the behavior of * in cases where there is overlap
|
|
// between the set of characters that repeat and the characters which follow.
|
|
// Without the ?, all states following the repeating state, up to a state which
|
|
// is reached by a character that doesn't overlap, will loop back into the
|
|
// repeating state. With the ?, the mark states following the *? DON'T loop
|
|
// back into the repeating state. Thus, "[a-z]*xyz" will match the longest
|
|
// sequence of letters that ends in "xyz," while "[a-z]*? will match the
|
|
// _shortest_ sequence of letters that ends in "xyz".
|
|
// We use extra bookkeeping to achieve this effect, since everything else works
|
|
// according to the "longest possible match" principle. The basic principle
|
|
// is that transitions out of a looping state are written in over the looping
|
|
// value instead of being reconciled, and that we copy the contents of the
|
|
// looping state into empty cells of all non-terminal states that follow the
|
|
// looping state.
|
|
//System.out.println("c = " + c + ", p = " + p + ", rule.length() = " + rule.length());
|
|
if (c == ASTERISK && p + 1 < rule.length() && rule[p + 1] == QUESTION) {
|
|
//System.out.println("Saw *?");
|
|
setLoopingStates(&decisionPointList, decisionPointList);
|
|
++p;
|
|
}
|
|
}
|
|
}
|
|
|
|
// a ( marks the beginning of a sequence of characters. Parentheses can either
|
|
// contain several alternative character sequences (i.e., "(ab|cd|ef)"), or
|
|
// they can contain a sequence of characters that can repeat (i.e., "(abc)*"). Thus,
|
|
// A () group can have multiple entry and exit points. To keep track of this,
|
|
// we reserve TWO spots on the decision-point stack. The top of the stack is
|
|
// the list of exit points, which becomes the current decision point list when
|
|
// the ) is reached. The next entry down is the decision point list at the
|
|
// beginning of the (), which becomes the current decision point list at every
|
|
// entry point.
|
|
// In addition to keeping track of the exit points and the active decision
|
|
// points before the ( (i.e., the places from which the () can be entered),
|
|
// we need to keep track of the entry points in case the expression loops
|
|
// (i.e., is followed by *). We do that by creating a dummy state in the
|
|
// state table and adding it to the decision point list (BEFORE it's duplicated
|
|
// on the stack). Nobody points to this state, so it'll get optimized out
|
|
// at the end. It exists only to hold the entry points in case the ()
|
|
// expression loops.
|
|
if (c == OPEN_PAREN) {
|
|
|
|
// add a new state to the state table to hold the entry points into
|
|
// the () expression
|
|
tempStateTable.addElement(new int16_t[numCategories + 1]);
|
|
|
|
// we have to adjust lastState and currentState to account for the
|
|
// new dummy state
|
|
lastState = currentState;
|
|
++currentState;
|
|
|
|
// add the current state to the decision point list (add it at the
|
|
// BEGINNING so we can find it later)
|
|
decisionPointList.insertElementAt((void*)currentState, 0);
|
|
|
|
// finally, push a copy of the current decision point list onto the
|
|
// stack (this keeps track of the active decision point list before
|
|
// the () expression), followed by an empty decision point list
|
|
// (this will hold the exit points)
|
|
UVector* clone = new UVector;
|
|
for (int32_t i = 0; i < decisionPointList.size(); i++) {
|
|
clone->addElement(decisionPointList[i]);
|
|
}
|
|
decisionPointStack.push(clone);
|
|
decisionPointStack.push(new UVector());
|
|
}
|
|
|
|
// a | separates alternative character sequences in a () expression. When
|
|
// a | is encountered, we add the current decision point list to the exit-point
|
|
// list, and restore the decision point list to its state prior to the (.
|
|
if (c == PIPE) {
|
|
|
|
// pick out the top two decision point lists on the stack
|
|
UVector* oneDown = (UVector*)decisionPointStack.pop();
|
|
UVector* twoDown = (UVector*)decisionPointStack.peek();
|
|
decisionPointStack.push(oneDown);
|
|
|
|
// append the current decision point list to the list below it
|
|
// on the stack (the list of exit points), and restore the
|
|
// current decision point list to its state before the () expression
|
|
for (int32_t i = 0; i < decisionPointList.size(); i++)
|
|
oneDown->addElement(decisionPointList[i]);
|
|
decisionPointList.removeAllElements();
|
|
for (int32_t i = 0; i < twoDown->size(); i++)
|
|
decisionPointList.addElement((*twoDown)[i]);
|
|
}
|
|
|
|
// a ) marks the end of a sequence of characters. We do one of two things
|
|
// depending on whether the sequence repeats (i.e., whether the ) is followed
|
|
// by *): If the sequence doesn't repeat, then the exit-point list is merged
|
|
// with the current decision point list and the decision point list from before
|
|
// the () is thrown away. If the sequence does repeat, then we fish out the
|
|
// state we were in before the ( and copy all of its forward transitions
|
|
// (i.e., every transition added by the () expression) into every state in the
|
|
// exit-point list and the current decision point list. The current decision
|
|
// point list is then merged with both the exit-point list AND the saved version
|
|
// of the decision point list from before the (). Then we throw out the *.
|
|
if (c == CLOSE_PAREN) {
|
|
|
|
// pull the exit point list off the stack, merge it with the current
|
|
// decision point list, and make the merged version the current
|
|
// decision point list
|
|
UVector* exitPoints = (UVector*)decisionPointStack.pop();
|
|
for (int32_t i = 0; i < exitPoints->size(); i++)
|
|
decisionPointList.addElement((*exitPoints)[i]);
|
|
delete exitPoints;
|
|
|
|
// if the ) isn't followed by a *, then all we have to do is throw
|
|
// away the other list on the decision point stack, and we're done
|
|
if (p + 1 >= rule.length() || (
|
|
rule[p + 1] != ASTERISK &&
|
|
rule[p + 1] != PLUS &&
|
|
rule[p + 1] != QUESTION)
|
|
) {
|
|
delete (UVector*)decisionPointStack.pop();
|
|
}
|
|
|
|
// but if the sequence repeats, we have a lot more work to do...
|
|
else {
|
|
|
|
// now exitPoints and decisionPointList have to point to equivalent
|
|
// vectors, but not the SAME vector
|
|
exitPoints = new UVector;
|
|
for (int32_t i = 0; i < decisionPointList.size(); i++)
|
|
exitPoints->addElement(decisionPointList[i]);
|
|
|
|
// pop the original decision point list off the stack
|
|
UVector* temp2 = (UVector*)decisionPointStack.pop();
|
|
|
|
// we squirreled away the row number of our entry point list
|
|
// at the beginning of the original decision point list. Fish
|
|
// that state number out and retrieve the entry point list
|
|
int32_t tempStateNum = (int32_t)temp2->firstElement();
|
|
int16_t* tempState = (int16_t*)tempStateTable.elementAt(tempStateNum);
|
|
|
|
// merge the original decision point list with the current
|
|
// decision point list
|
|
if (rule.charAt(p + 1) == QUESTION || rule.charAt(p + 1) == ASTERISK) {
|
|
for (int32_t i = 0; i < temp2->size(); i++)
|
|
decisionPointList.addElement((*temp2)[i]);
|
|
delete temp2;
|
|
}
|
|
|
|
// finally, copy every forward reference from the entry point
|
|
// list into every state in the new decision point list
|
|
if (rule[p + 1] == PLUS || rule[p + 1] == ASTERISK) {
|
|
for (int32_t i = 0; i < numCategories; i++) {
|
|
if (tempState[i] > tempStateNum) {
|
|
updateStateTable(*exitPoints,
|
|
UnicodeString((UChar)(i + 0x100)),
|
|
tempState[i]);
|
|
}
|
|
}
|
|
}
|
|
|
|
// update lastState and currentState, and throw away the *
|
|
lastState = currentState;
|
|
currentState = tempStateTable.size() - 1;
|
|
++p;
|
|
delete exitPoints;
|
|
}
|
|
}
|
|
|
|
// a / marks the position where the break is to go if the character sequence
|
|
// matches this rule. We update the flag word of every state on the decision
|
|
// point list to mark them as ending states, and take note of the fact that
|
|
// we've seen the slash
|
|
if (c == SLASH) {
|
|
sawEarlyBreak = TRUE;
|
|
for (int32_t i = 0; i < decisionPointList.size(); i++) {
|
|
state = (int16_t*)tempStateTable.elementAt((int32_t)decisionPointList[i]);
|
|
state[numCategories] |= LOOKAHEAD_STATE_FLAG;
|
|
}
|
|
}
|
|
|
|
// if we get here without executing any of the above clauses, we have a
|
|
// syntax error. However, for now we just ignore the offending character
|
|
// and move on
|
|
/*
|
|
debugPrintln("====Parsed \"" + rule.substring(0, p + 1) + "\"...");
|
|
System.out.println(" currentState = " + currentState);
|
|
debugPrintVectorOfVectors(" decisionPointStack:", " ", decisionPointStack);
|
|
debugPrintVector(" ", decisionPointList);
|
|
debugPrintVector(" loopingStates = ", loopingStates);
|
|
debugPrintVector(" statesToBackfill = ", statesToBackfill);
|
|
System.out.println(" sawEarlyBreak = " + sawEarlyBreak);
|
|
debugPrintTempStateTable();
|
|
*/
|
|
|
|
// clearLoopingStates is a signal back from updateStateTable() that we've
|
|
// transitioned to a state that won't loop back to the current looping
|
|
// state. (In other words, we've gotten to a point where we can no longer
|
|
// go back into a *? we saw earlier.) Clear out the list of looping states
|
|
// and backfill any states that need to be backfilled.
|
|
if (clearLoopingStates) {
|
|
setLoopingStates(0, decisionPointList);
|
|
}
|
|
|
|
// advance to the next character, now that we've processed the current
|
|
// character
|
|
++p;
|
|
}
|
|
|
|
// this takes care of backfilling any states that still need to be backfilled
|
|
setLoopingStates(0, decisionPointList);
|
|
|
|
// when we reach the end of the string, we do a postprocessing step to mark the
|
|
// end states. The decision point list contains every state that can transition
|
|
// to the end state-- that is, every state that is the last state in a sequence
|
|
// that matches the rule. All of these states are considered "mark states"
|
|
// or "accepting states"-- that is, states that cause the position returned from
|
|
// next() to be updated. A mark state represents a possible break position.
|
|
// This allows us to look ahead and remember how far the rule matched
|
|
// before following the new branch (see next() for more information).
|
|
// The temporary state table has an extra "flag column" at the end where this
|
|
// information is stored. We mark the end states by setting a flag in their
|
|
// flag column.
|
|
// Now if we saw the / in the rule, then everything after it is lookahead
|
|
// material and the break really goes where the slash is. In this case,
|
|
// we mark these states as BOTH accepting states and lookahead states. This
|
|
// signals that these states cause the break position to be updated to the
|
|
// position of the slash rather than the current break position.
|
|
for (int32_t i = 0; i < decisionPointList.size(); i++) {
|
|
int32_t rowNum = (int32_t)decisionPointList[i];
|
|
state = (int16_t*)tempStateTable[rowNum];
|
|
state[numCategories] |= END_STATE_FLAG;
|
|
if (sawEarlyBreak) {
|
|
state[numCategories] |= LOOKAHEAD_STATE_FLAG;
|
|
}
|
|
}
|
|
/*
|
|
debugPrintln("====Parsed \"" + rule + ";");
|
|
System.out.println();
|
|
System.out.println(" currentState = " + currentState);
|
|
debugPrintVectorOfVectors(" decisionPointStack:", " ", decisionPointStack);
|
|
debugPrintVector(" ", decisionPointList);
|
|
debugPrintVector(" loopingStates = ", loopingStates);
|
|
debugPrintVector(" statesToBackfill = ", statesToBackfill);
|
|
System.out.println(" sawEarlyBreak = " + sawEarlyBreak);
|
|
debugPrintTempStateTable();
|
|
*/
|
|
}
|
|
|
|
/**
|
|
* Update entries in the state table, and merge states when necessary to keep
|
|
* the table deterministic.
|
|
* @param rows The list of rows that need updating (the decision point list)
|
|
* @param pendingChars A character category list, encoded in a String. This is the
|
|
* list of the columns that need updating.
|
|
* @param newValue Update the cells specfied above to contain this value
|
|
*/
|
|
void
|
|
RuleBasedBreakIteratorBuilder::updateStateTable(const UVector& rows,
|
|
const UnicodeString& pendingChars,
|
|
int16_t newValue)
|
|
{
|
|
// create a dummy state that has the specified row number (newValue) in
|
|
// the cells that need to be updated (those specified by pendingChars)
|
|
// and 0 in the other cells
|
|
int16_t* newValues = new int16_t[numCategories + 1];
|
|
for (int32_t i = 0; i < pendingChars.length(); i++)
|
|
newValues[(int32_t)(pendingChars[i]) - 0x100] = newValue;
|
|
|
|
// go through the list of rows to update, and update them by calling
|
|
// mergeStates() to merge them the the dummy state we created
|
|
for (int32_t i = 0; i < rows.size(); i++) {
|
|
mergeStates((int32_t)rows[i], newValues, rows);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* The real work of making the state table deterministic happens here. This function
|
|
* merges a state in the state table (specified by rowNum) with a state that is
|
|
* passed in (newValues). The basic process is to copy the nonzero cells in newStates
|
|
* into the state in the state table (we'll call that oldValues). If there's a
|
|
* collision (i.e., if the same cell has a nonzero value in both states, and it's
|
|
* not the SAME value), then we have to reconcile the collision. We do this by
|
|
* creating a new state, adding it to the end of the state table, and using this
|
|
* function recursively to merge the original two states into a single, combined
|
|
* state. This process may happen recursively (i.e., each successive level may
|
|
* involve collisions). To prevent infinite recursion, we keep a log of merge
|
|
* operations. Any time we're merging two states we've merged before, we can just
|
|
* supply the row number for the result of that merge operation rather than creating
|
|
* a new state just like it.
|
|
* @param rowNum The row number in the state table of the state to be updated
|
|
* @param newValues The state to merge it with.
|
|
* @param rowsBeingUpdated A copy of the list of rows passed to updateStateTable()
|
|
* (itself a copy of the decision point list from parseRule()). Newly-created
|
|
* states get added to the decision point list if their "parents" were on it.
|
|
*/
|
|
void
|
|
RuleBasedBreakIteratorBuilder::mergeStates(int32_t rowNum,
|
|
int16_t* newValues,
|
|
const UVector& rowsBeingUpdated)
|
|
{
|
|
int16_t* oldValues = (int16_t*)(tempStateTable[rowNum]);
|
|
/*
|
|
System.out.print("***Merging " + rowNum + ":");
|
|
for (int32_t i = 0; i < oldValues.length; i++) System.out.print("\t" + oldValues[i]);
|
|
System.out.println();
|
|
System.out.print(" with \t");
|
|
for (int32_t i = 0; i < newValues.length; i++) System.out.print("\t" + newValues[i]);
|
|
System.out.println();
|
|
*/
|
|
|
|
UBool isLoopingState = loopingStates.contains((void*)rowNum);
|
|
|
|
// for each of the cells in the rows we're reconciling, do...
|
|
for (int32_t i = 0; i < numCategories; i++) {
|
|
|
|
// if they contain the same value, we don't have to do anything
|
|
if (oldValues[i] == newValues[i]) {
|
|
continue;
|
|
}
|
|
|
|
// if oldValues is a looping state and the state the current cell points to
|
|
// is too, then we can just stomp over the current value of that cell (and
|
|
// set the clear-looping-states flag if necessary)
|
|
else if (isLoopingState && loopingStates.contains((void*)oldValues[i])) {
|
|
if (newValues[i] != 0) {
|
|
if (oldValues[i] == 0) {
|
|
clearLoopingStates = TRUE;
|
|
}
|
|
oldValues[i] = newValues[i];
|
|
}
|
|
}
|
|
|
|
// if the current cell in oldValues is 0, copy in the corresponding value
|
|
// from newValues
|
|
else if (oldValues[i] == 0) {
|
|
oldValues[i] = newValues[i];
|
|
}
|
|
|
|
// the last column of each row is the flag column. Take care to merge the
|
|
// flag words correctly
|
|
else if (i == numCategories) {
|
|
oldValues[i] = (int16_t)((newValues[i] & ALL_FLAGS) | oldValues[i]);
|
|
}
|
|
|
|
// if both newValues and oldValues have a nonzero value in the current
|
|
// cell, and it isn't the same value both places...
|
|
else if (oldValues[i] != 0 && newValues[i] != 0) {
|
|
|
|
// look up this pair of cell values in the merge list. If it's
|
|
// found, update the cell in oldValues to point to the merged state
|
|
int32_t combinedRowNum = searchMergeList(oldValues[i], newValues[i]);
|
|
if (combinedRowNum != 0) {
|
|
oldValues[i] = (int16_t)combinedRowNum;
|
|
}
|
|
|
|
// otherwise, we have to reconcile them...
|
|
else {
|
|
// copy our row numbers into variables to make things easier
|
|
int32_t oldRowNum = oldValues[i];
|
|
int32_t newRowNum = newValues[i];
|
|
combinedRowNum = tempStateTable.size();
|
|
|
|
// add this pair of row numbers to the merge list (create it first
|
|
// if we haven't created the merge list yet)
|
|
int32_t* entry = new int32_t[3];
|
|
entry[0] = oldRowNum;
|
|
entry[1] = newRowNum;
|
|
entry[2] = combinedRowNum;
|
|
mergeList.addElement(entry);
|
|
|
|
//System.out.println("***At " + rowNum + ", merging " + oldRowNum + " and " + newRowNum + " into " + combinedRowNum);
|
|
|
|
// create a new row to represent the merged state, and copy the
|
|
// contents of oldRow into it, then add it to the end of the
|
|
// state table and update the original row (oldValues) to point
|
|
// to the new, merged, state
|
|
int16_t* newRow = new int16_t[numCategories + 1];
|
|
int16_t* oldRow = (int16_t*)(tempStateTable[oldRowNum]);
|
|
uprv_memcpy(newRow, oldRow, (numCategories + 1) * sizeof int16_t);
|
|
tempStateTable.addElement(newRow);
|
|
oldValues[i] = (int16_t)combinedRowNum;
|
|
|
|
|
|
//System.out.println("lastOldRowNum = " + lastOldRowNum);
|
|
//System.out.println("lastCombinedRowNum = " + lastCombinedRowNum);
|
|
//System.out.println("decisionPointList.contains(lastOldRowNum) = " + decisionPointList.contains(new Integer(lastOldRowNum)));
|
|
//System.out.println("decisionPointList.contains(lastCombinedRowNum) = " + decisionPointList.contains(new Integer(lastCombinedRowNum)));
|
|
|
|
// if the decision point list contains either of the parent rows,
|
|
// update it to include the new row as well
|
|
if ((decisionPointList.contains((void*)oldRowNum)
|
|
|| decisionPointList.contains((void*)newRowNum))
|
|
&& !decisionPointList.contains((void*)combinedRowNum)
|
|
) {
|
|
decisionPointList.addElement((void*)combinedRowNum);
|
|
}
|
|
|
|
// do the same thing with the list of rows being updated
|
|
if ((rowsBeingUpdated.contains((void*)oldRowNum)
|
|
|| rowsBeingUpdated.contains((void*)newRowNum))
|
|
&& !rowsBeingUpdated.contains((void*)combinedRowNum)
|
|
) {
|
|
decisionPointList.addElement((void*)combinedRowNum);
|
|
}
|
|
// now (groan) do the same thing for all the entries on the
|
|
// decision point stack
|
|
for (int32_t k = 0; k < decisionPointStack.size(); k++) {
|
|
UVector* dpl = (UVector*)decisionPointStack[k];
|
|
if ((dpl->contains((void*)oldRowNum)
|
|
|| dpl->contains((void*)newRowNum))
|
|
&& !dpl->contains((void*)combinedRowNum)
|
|
) {
|
|
dpl->addElement((void*)combinedRowNum);
|
|
}
|
|
}
|
|
|
|
// FINALLY (puff puff puff), call mergeStates() recursively to copy
|
|
// the row referred to by newValues into the new row and resolve any
|
|
// conflicts that come up at that level
|
|
mergeStates(combinedRowNum, (int16_t*)(tempStateTable.elementAt(
|
|
newValues[i])), rowsBeingUpdated);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* The merge list is a list of pairs of rows that have been merged somewhere in
|
|
* the process of building this state table, along with the row number of the
|
|
* row containing the merged state. This function looks up a pair of row numbers
|
|
* and returns the row number of the row they combine into. (It returns 0 if
|
|
* this pair of rows isn't in the merge list.)
|
|
*/
|
|
int32_t
|
|
RuleBasedBreakIteratorBuilder::searchMergeList(int32_t a, int32_t b)
|
|
{
|
|
int32_t* entry;
|
|
for (int32_t i = 0; i < mergeList.size(); i++) {
|
|
entry = (int32_t*)(mergeList[i]);
|
|
|
|
// we have a hit if the two row numbers match the two row numbers
|
|
// in the beginning of the entry (the two that combine), in either
|
|
// order
|
|
if ((entry[0] == a && entry[1] == b) || (entry[0] == b && entry[1] == a)) {
|
|
return entry[2];
|
|
}
|
|
|
|
// we also have a hit if one of the two row numbers matches the marged
|
|
// row number and the other one matches one of the original row numbers
|
|
if ((entry[2] == a && (entry[0] == b || entry[1] == b))) {
|
|
return entry[2];
|
|
}
|
|
if ((entry[2] == b && (entry[0] == a || entry[1] == a))) {
|
|
return entry[2];
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* This function is used to update the list of current loooping states (i.e.,
|
|
* states that are controlled by a *? construct). It backfills values from
|
|
* the looping states into unpopulated cells of the states that are currently
|
|
* marked for backfilling, and then updates the list of looping states to be
|
|
* the new list
|
|
* @param newLoopingStates The list of new looping states
|
|
* @param endStates The list of states to treat as end states (states that
|
|
* can exit the loop).
|
|
*/
|
|
void
|
|
RuleBasedBreakIteratorBuilder::setLoopingStates(const UVector* newLoopingStates,
|
|
const UVector& endStates)
|
|
{
|
|
// if the current list of looping states isn't empty, we have to backfill
|
|
// values from the looping states into the states that are waiting to be
|
|
// backfilled
|
|
if (!loopingStates.isEmpty()) {
|
|
int32_t loopingState = (int32_t)loopingStates.lastElement();
|
|
int32_t rowNum;
|
|
|
|
// don't backfill into an end state OR any state reachable from an end state
|
|
// (since the search for reachable states is recursive, it's split out into
|
|
// a separate function, eliminateBackfillStates(), below)
|
|
for (int32_t i = 0; i < endStates.size(); i++) {
|
|
eliminateBackfillStates((int32_t)endStates[i]);
|
|
}
|
|
|
|
// we DON'T actually backfill the states that need to be backfilled here.
|
|
// Instead, we MARK them for backfilling. The reason for this is that if
|
|
// there are multiple rules in the state-table description, the looping
|
|
// states may have some of their values changed by a succeeding rule, and
|
|
// this wouldn't be reflected in the backfilled states. We mark a state
|
|
// for backfilling by putting the row number of the state to copy from
|
|
// into the flag cell at the end of the row
|
|
for (int32_t i = 0; i < statesToBackfill.size(); i++) {
|
|
rowNum = (int32_t)statesToBackfill.elementAt(i);
|
|
int16_t* state = (int16_t*)tempStateTable[rowNum];
|
|
state[numCategories] =
|
|
(int16_t)((state[numCategories] & ALL_FLAGS) | loopingState);
|
|
}
|
|
statesToBackfill.removeAllElements();
|
|
loopingStates.removeAllElements();
|
|
}
|
|
|
|
if (newLoopingStates != 0) {
|
|
for (int32_t i = 0; i < newLoopingStates->size(); i++) {
|
|
loopingStates.addElement((*newLoopingStates)[i]);
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* This removes "ending states" and states reachable from them from the
|
|
* list of states to backfill.
|
|
* @param The row number of the state to remove from the backfill list
|
|
*/
|
|
void
|
|
RuleBasedBreakIteratorBuilder::eliminateBackfillStates(int32_t baseState)
|
|
{
|
|
// don't do anything unless this state is actually in the backfill list...
|
|
if (statesToBackfill.contains((void*)baseState)) {
|
|
|
|
// if it is, take it out
|
|
statesToBackfill.removeElement((void*)baseState);
|
|
|
|
// then go through and recursively call this function for every
|
|
// state that the base state points to
|
|
int16_t* state = (int16_t*)tempStateTable[baseState];
|
|
for (int32_t i = 0; i < numCategories; i++) {
|
|
if (state[i] != 0) {
|
|
eliminateBackfillStates(state[i]);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* This function completes the backfilling process by actually doing the
|
|
* backfilling on the states that are marked for it
|
|
*/
|
|
void
|
|
RuleBasedBreakIteratorBuilder::backfillLoopingStates(void)
|
|
{
|
|
int16_t* state;
|
|
int16_t* loopingState = 0;
|
|
int32_t loopingStateRowNum = 0;
|
|
int32_t fromState;
|
|
|
|
// for each state in the state table...
|
|
for (int32_t i = 0; i < tempStateTable.size(); i++) {
|
|
state = (int16_t*)tempStateTable[i];
|
|
|
|
// check the state's flag word to see if it's marked for backfilling
|
|
// (it's marked for backfilling if any bits other than the two high-order
|
|
// bits are set-- if they are, then the flag word, minus the two high bits,
|
|
// is the row number to copy from)
|
|
fromState = state[numCategories] & ~ALL_FLAGS;
|
|
if (fromState > 0) {
|
|
|
|
// load up the state to copy from (if we haven't already)
|
|
if (fromState != loopingStateRowNum) {
|
|
loopingStateRowNum = fromState;
|
|
loopingState = (int16_t*)tempStateTable[loopingStateRowNum];
|
|
}
|
|
|
|
// clear out the backfill part of the flag word
|
|
state[numCategories] &= ALL_FLAGS;
|
|
|
|
// then fill all zero cells in the current state with values
|
|
// from the corresponding cells of the fromState
|
|
for (int32_t j = 0; j < numCategories + 1; j++) {
|
|
if (state[j] == 0) {
|
|
state[j] = loopingState[j];
|
|
}
|
|
else if (state[j] == DONT_LOOP_FLAG) {
|
|
state[j] = 0;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* This function completes the state-table-building process by doing several
|
|
* postprocessing steps and copying everything into its final resting place
|
|
* in the iterator itself
|
|
* @param forward TRUE if we're working on the forward state table
|
|
*/
|
|
void
|
|
RuleBasedBreakIteratorBuilder::finishBuildingStateTable(UBool forward)
|
|
{
|
|
//debugPrintTempStateTable();
|
|
// start by backfilling the looping states
|
|
backfillLoopingStates();
|
|
//debugPrintTempStateTable();
|
|
|
|
int32_t* rowNumMap = new int32_t[tempStateTable.size()];
|
|
int32_t rowNumMapSize = tempStateTable.size();
|
|
UStack rowsToFollow;
|
|
rowsToFollow.push((void*)1);
|
|
rowNumMap[1] = 1;
|
|
|
|
// determine which states are no longer reachable from the start state
|
|
// (the reachable states will have their row numbers in the row number
|
|
// map, and the nonreachable states will have zero in the row number map)
|
|
while (rowsToFollow.size() != 0) {
|
|
int32_t rowNum = (int32_t)rowsToFollow.pop();
|
|
int16_t* row = (int16_t*)(tempStateTable[rowNum]);
|
|
|
|
for (int32_t i = 0; i < numCategories; i++) {
|
|
if (row[i] != 0) {
|
|
if (rowNumMap[row[i]] == 0) {
|
|
rowNumMap[row[i]] = row[i];
|
|
rowsToFollow.push((void*)row[i]);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
/*
|
|
System.out.println("The following rows are not reachable:");
|
|
for (int32_t i = 1; i < rowNumMap.length; i++)
|
|
if (rowNumMap[i] == 0) System.out.print("\t" + i);
|
|
System.out.println();
|
|
*/
|
|
|
|
int32_t newRowNum;
|
|
|
|
// algorithm for minimizing the number of states in the table adapted from
|
|
// Aho & Ullman, "Principles of Compiler Design"
|
|
// The basic idea here is to organize the states into classes. When we're done,
|
|
// all states in the same class can be considered identical and all but one eliminated.
|
|
|
|
// initially assign states to classes based on the number of populated cells they
|
|
// contain (the class number is the number of populated cells)
|
|
int32_t* stateClasses = new int32_t[tempStateTable.size()];
|
|
int32_t nextClass = numCategories + 1;
|
|
int16_t* state1 = 0;
|
|
int16_t* state2 = 0;
|
|
for (int32_t i = 1; i < tempStateTable.size(); i++) {
|
|
if (rowNumMap[i] == 0) {
|
|
continue;
|
|
}
|
|
state1 = (int16_t*)tempStateTable[i];
|
|
for (int32_t j = 0; j < numCategories; j++) {
|
|
if (state1[j] != 0) {
|
|
++stateClasses[i];
|
|
}
|
|
}
|
|
if (stateClasses[i] == 0) {
|
|
stateClasses[i] = nextClass;
|
|
}
|
|
}
|
|
++nextClass;
|
|
|
|
// then, for each class, elect the first member of that class as that class's
|
|
// "representative". For each member of the class, compare it to the "representative."
|
|
// If there's a column position where the state being tested transitions to a
|
|
// state in a DIFFERENT class from the class where the "representative" transitions,
|
|
// then move the state into a new class. Repeat this process until no new classes
|
|
// are created.
|
|
int32_t currentClass;
|
|
int32_t lastClass;
|
|
UBool split;
|
|
|
|
do {
|
|
//System.out.println("Making a pass...");
|
|
currentClass = 1;
|
|
lastClass = nextClass;
|
|
while (currentClass < nextClass) {
|
|
//System.out.print("States in class #" + currentClass +":");
|
|
split = FALSE;
|
|
state1 = state2 = 0;
|
|
for (int32_t i = 0; i < tempStateTable.size(); i++) {
|
|
if (stateClasses[i] == currentClass) {
|
|
//System.out.print("\t" + i);
|
|
if (state1 == 0) {
|
|
state1 = (int16_t*)tempStateTable[i];
|
|
}
|
|
else {
|
|
state2 = (int16_t*)tempStateTable[i];
|
|
for (int32_t j = 0; j < numCategories + 1; j++) {
|
|
if ((j == numCategories && state1[j] != state2[j] && forward)
|
|
|| (j != numCategories && stateClasses[state1[j]]
|
|
!= stateClasses[state2[j]])) {
|
|
stateClasses[i] = nextClass;
|
|
split = TRUE;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
if (split) {
|
|
++nextClass;
|
|
}
|
|
++currentClass;
|
|
//System.out.println();
|
|
}
|
|
} while (lastClass != nextClass);
|
|
|
|
// at this point, all of the states in a class except the first one (the
|
|
//"representative") can be eliminated, so update the row-number map accordingly
|
|
int32_t* representatives = new int32_t[nextClass];
|
|
for (int32_t i = 1; i < tempStateTable.size(); i++) {
|
|
if (representatives[stateClasses[i]] == 0) {
|
|
representatives[stateClasses[i]] = i;
|
|
}
|
|
else {
|
|
rowNumMap[i] = representatives[stateClasses[i]];
|
|
}
|
|
}
|
|
delete [] stateClasses;
|
|
delete [] representatives;
|
|
//System.out.println("Renumbering...");
|
|
|
|
// renumber all remaining rows...
|
|
// first drop all that are either unreferenced or not a class representative
|
|
for (int32_t i = 1; i < rowNumMapSize; i++) {
|
|
if (rowNumMap[i] != i) {
|
|
delete [] tempStateTable[i];
|
|
tempStateTable.setElementAt(0, i);
|
|
}
|
|
}
|
|
|
|
// then calculate everybody's new row number and update the row
|
|
// number map appropriately (the first pass updates the row numbers
|
|
// of all the class representatives [the rows we're keeping], and the
|
|
// second pass updates the cross references for all the rows that
|
|
// are being deleted)
|
|
newRowNum = 1;
|
|
for (int32_t i = 1; i < rowNumMapSize; i++) {
|
|
if (tempStateTable[i] != 0) {
|
|
rowNumMap[i] = newRowNum++;
|
|
}
|
|
}
|
|
for (int32_t i = 1; i < rowNumMapSize; i++) {
|
|
if (tempStateTable[i] == 0) {
|
|
rowNumMap[i] = rowNumMap[rowNumMap[i]];
|
|
}
|
|
}
|
|
//for (int32_t i = 1; i < rowNumMap.length; i++) rowNumMap[i] = i; int32_t newRowNum = rowNumMap.length;
|
|
|
|
// allocate the permanent state table, and copy the remaining rows into it
|
|
// (adjusting all the cell values, of course)
|
|
|
|
// this section does that for the forward state table
|
|
if (forward) {
|
|
tables->endStates = new UBool[newRowNum];
|
|
tables->lookaheadStates = new UBool[newRowNum];
|
|
tables->stateTable = new int16_t[newRowNum * numCategories];
|
|
int32_t p = 0;
|
|
int32_t p2 = 0;
|
|
for (int32_t i = 0; i < tempStateTable.size(); i++) {
|
|
int16_t* row = (int16_t*)(tempStateTable[i]);
|
|
if (row == 0) {
|
|
continue;
|
|
}
|
|
for (int32_t j = 0; j < numCategories; j++) {
|
|
tables->stateTable[p] = (int16_t)(rowNumMap[row[j]]);
|
|
++p;
|
|
}
|
|
tables->endStates[p2] = ((row[numCategories] & END_STATE_FLAG) != 0);
|
|
tables->lookaheadStates[p2] = ((row[numCategories] & LOOKAHEAD_STATE_FLAG) != 0);
|
|
++p2;
|
|
}
|
|
}
|
|
|
|
// and this section does it for the backward state table
|
|
else {
|
|
tables->backwardsStateTable = new int16_t[newRowNum * numCategories];
|
|
int32_t p = 0;
|
|
for (int32_t i = 0; i < tempStateTable.size(); i++) {
|
|
int16_t* row = (int16_t*)(tempStateTable[i]);
|
|
if (row == 0) {
|
|
continue;
|
|
}
|
|
for (int32_t j = 0; j < numCategories; j++) {
|
|
tables->backwardsStateTable[p] = (int16_t)(rowNumMap[row[j]]);
|
|
++p;
|
|
}
|
|
}
|
|
}
|
|
|
|
delete [] rowNumMap;
|
|
}
|
|
|
|
/**
|
|
* This function builds the backward state table from the forward state
|
|
* table and any additional rules (identified by the ! on the front)
|
|
* supplied in the description
|
|
*/
|
|
void
|
|
RuleBasedBreakIteratorBuilder::buildBackwardsStateTable(UErrorCode& err)
|
|
{
|
|
if (U_FAILURE(err))
|
|
return;
|
|
|
|
// create the temporary state table and seed it with two rows (row 0
|
|
// isn't used for anything, and we have to create row 1 (the initial
|
|
// state) before we can do anything else
|
|
tempStateTable.removeAllElements();
|
|
tempStateTable.addElement(new int16_t[numCategories + 1]);
|
|
tempStateTable.addElement(new int16_t[numCategories + 1]);
|
|
|
|
// although the backwards state table is built automatically from the forward
|
|
// state table, there are some situations (the default sentence-break rules,
|
|
// for example) where this doesn't yield enough stop states, causing a dramatic
|
|
// drop in performance. To help with these cases, the user may supply
|
|
// supplemental rules that are added to the backward state table. These have
|
|
// the same syntax as the normal break rules, but begin with BANG to distinguish
|
|
// them from normal break rules
|
|
for (int32_t i = 0; i < tempRuleList.size(); i++) {
|
|
UnicodeString* rule = (UnicodeString*)tempRuleList[i];
|
|
if ((*rule)[0] == BANG) {
|
|
rule->remove(0, 1);
|
|
parseRule(*rule, FALSE);
|
|
}
|
|
}
|
|
backfillLoopingStates();
|
|
|
|
// Backwards iteration is qualitatively different from forwards iteration.
|
|
// This is because backwards iteration has to be made to operate from no context
|
|
// at all-- the user should be able to ask BreakIterator for the break position
|
|
// immediately on either side of some arbitrary offset in the text. The
|
|
// forward iteration table doesn't let us do that-- it assumes complete
|
|
// information on the context, which means starting from the beginning of the
|
|
// document.
|
|
// The way we do backward and random-access iteration is to back up from the
|
|
// current (or user-specified) position until we see something we're sure is
|
|
// a break position (it may not be the last break position immediately
|
|
// preceding our starting point, however). Then we roll forward from there to
|
|
// locate the actual break position we're after.
|
|
// This means that the backwards state table doesn't have to identify every
|
|
// break position, allowing the building algorithm to be much simpler. Here,
|
|
// we use a "pairs" approach, scanning the forward-iteration state table for
|
|
// pairs of character categories we ALWAYS break between, and building a state
|
|
// table from that information. No context is required-- all this state table
|
|
// looks at is a pair of adjacent characters.
|
|
|
|
// It's possible that the user has supplied supplementary rules (see above).
|
|
// This has to be done first to keep parseRule() and friends from becoming
|
|
// EVEN MORE complicated. The automatically-generated states are appended
|
|
// onto the end of the state table, and then the two sets of rules are
|
|
// stitched together at the end. Take note of the row number of the
|
|
// first row of the auromatically-generated part.
|
|
int32_t backTableOffset = tempStateTable.size();
|
|
if (backTableOffset > 2) {
|
|
++backTableOffset;
|
|
}
|
|
|
|
// the automatically-generated part of the table models a two-dimensional
|
|
// array where the two dimensions represent the two characters we're currently
|
|
// looking at. To model this as a state table, we actually need one additional
|
|
// row to represent the initial state. It gets populated with the row numbers
|
|
// of the other rows (in order).
|
|
for (int32_t i = 0; i < numCategories + 1; i++)
|
|
tempStateTable.addElement(new int16_t[numCategories + 1]);
|
|
|
|
int16_t* state = (int16_t*)tempStateTable[backTableOffset - 1];
|
|
for (int32_t i = 0; i < numCategories; i++)
|
|
state[i] = (int16_t)(i + backTableOffset);
|
|
|
|
// scavenge the forward state table for pairs of character categories
|
|
// that always have a break between them. The algorithm is as follows:
|
|
// Look down each column in the state table. For each nonzero cell in
|
|
// that column, look up the row it points to. For each nonzero cell in
|
|
// that row, populate a cell in the backwards state table: the row number
|
|
// of that cell is the number of the column we were scanning (plus the
|
|
// offset that locates this sub-table), and the column number of that cell
|
|
// is the column number of the nonzero cell we just found. This cell is
|
|
// populated with its own column number (adjusted according to the actual
|
|
// location of the sub-table). This process will produce a state table
|
|
// whose behavior is the same as looking up successive pairs of characters
|
|
// in an array of Booleans to determine whether there is a break.
|
|
int32_t numRows = tempStateTable.size() / numCategories;
|
|
for (int32_t column = 0; column < numCategories; column++) {
|
|
for (int32_t row = 0; row < numRows; row++) {
|
|
int32_t nextRow = tables->lookupState(row, column);
|
|
if (nextRow != 0) {
|
|
for (int32_t nextColumn = 0; nextColumn < numCategories; nextColumn++) {
|
|
int32_t cellValue = tables->lookupState(nextRow, nextColumn);
|
|
if (cellValue != 0) {
|
|
state = (int16_t*)tempStateTable[nextColumn + backTableOffset];
|
|
state[column] = (int16_t)(column + backTableOffset);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
//debugPrintTempStateTable();
|
|
// if the user specified some backward-iteration rules with the ! token,
|
|
// we have to merge the resulting state table with the auto-generated one
|
|
// above. First copy the populated cells from row 1 over the populated
|
|
// cells in the auto-generated table. Then copy values from row 1 of the
|
|
// auto-generated table into all of the the unpopulated cells of the
|
|
// rule-based table.
|
|
if (backTableOffset > 1) {
|
|
|
|
// for every row in the auto-generated sub-table, if a cell is
|
|
// populated that is also populated in row 1 of the rule-based
|
|
// sub-table, copy the value from row 1 over the value in the
|
|
// auto-generated sub-table
|
|
state = (int16_t*)tempStateTable[1];
|
|
for (int32_t i = backTableOffset - 1; i < tempStateTable.size(); i++) {
|
|
int16_t* state2 = (int16_t*)tempStateTable[i];
|
|
for (int32_t j = 0; j < numCategories; j++) {
|
|
if (state[j] != 0 && state2[j] != 0) {
|
|
state2[j] = state[j];
|
|
}
|
|
}
|
|
}
|
|
|
|
// now, for every row in the rule-based sub-table that is not
|
|
// an end state, fill in all unpopulated cells with the values
|
|
// of the corresponding cells in the first row of the auto-
|
|
// generated sub-table.
|
|
state = (int16_t*)tempStateTable[backTableOffset - 1];
|
|
for (int32_t i = 1; i < backTableOffset - 1; i++) {
|
|
int16_t* state2 = (int16_t*)tempStateTable[i];
|
|
if ((state2[numCategories] & END_STATE_FLAG) == 0) {
|
|
for (int32_t j = 0; j < numCategories; j++) {
|
|
if (state2[j] == 0) {
|
|
state2[j] = state[j];
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
//debugPrintTempStateTable();
|
|
|
|
// finally, clean everything up and copy it into the actual BreakIterator
|
|
// by calling finishBuildingStateTable()
|
|
finishBuildingStateTable(FALSE);
|
|
/*
|
|
System.out.print("C:\t");
|
|
for (int32_t i = 0; i < numCategories; i++)
|
|
System.out.print(Integer.toString(i) + "\t");
|
|
System.out.println(); System.out.print("=================================================");
|
|
for (int32_t i = 0; i < backwardsStateTable.length; i++) {
|
|
if (i % numCategories == 0) {
|
|
System.out.println();
|
|
System.out.print(Integer.toString(i / numCategories) + ":\t");
|
|
}
|
|
if (backwardsStateTable[i] == 0) System.out.print(".\t"); else System.out.print(Integer.toString(backwardsStateTable[i]) + "\t");
|
|
}
|
|
System.out.println();
|
|
*/
|
|
}
|
|
|
|
void
|
|
RuleBasedBreakIteratorBuilder::setUpErrorMessage(const UnicodeString& message,
|
|
int32_t position,
|
|
const UnicodeString& context)
|
|
{
|
|
static UChar lbrks[] = { 0x000a, 0x000a };
|
|
|
|
errorMessage = context;
|
|
errorMessage.insert(position, lbrks, 2);
|
|
errorMessage.insert(0, lbrks, 1);
|
|
errorMessage.insert(0, message);
|
|
}
|