275 lines
11 KiB
C++
275 lines
11 KiB
C++
/*
|
|
**********************************************************************
|
|
* Copyright (C) 1999, International Business Machines
|
|
* Corporation and others. All Rights Reserved.
|
|
**********************************************************************
|
|
* Date Name Description
|
|
* 11/17/99 aliu Creation.
|
|
**********************************************************************
|
|
*/
|
|
#include "rbt_set.h"
|
|
#include "rbt_rule.h"
|
|
#include "unicode/unistr.h"
|
|
|
|
/* Note: There was an old implementation that indexed by first letter of
|
|
* key. Problem with this is that key may not have a meaningful first
|
|
* letter; e.g., {Lu}>*. One solution is to keep a separate vector of all
|
|
* rules whose intial key letter is a category variable. However, the
|
|
* problem is that they must be kept in order with respect to other rules.
|
|
* One solution -- add a sequence number to each rule. Do the usual
|
|
* first-letter lookup, and also a lookup from the spare bin with rules like
|
|
* {Lu}>*. Take the lower sequence number. This seems complex and not
|
|
* worth the trouble, but we may revisit this later. For documentation (or
|
|
* possible resurrection) the old code is included below, commented out
|
|
* with the remark "// OLD INDEXED IMPLEMENTATION". Under the old
|
|
* implementation, <code>rules</code> is a Hashtable, not a Vector.
|
|
*/
|
|
|
|
/**
|
|
* Construct a new empty rule set.
|
|
*/
|
|
TransliterationRuleSet::TransliterationRuleSet() {
|
|
maxContextLength = 0;
|
|
ruleVector = new UVector();
|
|
rules = NULL;
|
|
}
|
|
|
|
/**
|
|
* Destructor.
|
|
*/
|
|
TransliterationRuleSet::~TransliterationRuleSet() {
|
|
delete ruleVector;
|
|
delete[] rules;
|
|
}
|
|
|
|
/**
|
|
* Return the maximum context length.
|
|
* @return the length of the longest preceding context.
|
|
*/
|
|
int32_t TransliterationRuleSet::getMaximumContextLength(void) const {
|
|
return maxContextLength;
|
|
}
|
|
|
|
/**
|
|
* Add a rule to this set. Rules are added in order, and order is
|
|
* significant.
|
|
*
|
|
* <p>Once freeze() is called, this method must not be called.
|
|
* @param adoptedRule the rule to add
|
|
*/
|
|
void TransliterationRuleSet::addRule(TransliterationRule* adoptedRule,
|
|
UErrorCode& status) {
|
|
if (U_FAILURE(status)) {
|
|
delete adoptedRule;
|
|
return;
|
|
}
|
|
if (ruleVector == NULL) {
|
|
// throw new IllegalArgumentException("Cannot add rules after freezing");
|
|
status = U_ILLEGAL_ARGUMENT_ERROR;
|
|
delete adoptedRule;
|
|
return;
|
|
}
|
|
ruleVector->addElement(adoptedRule);
|
|
|
|
int32_t len;
|
|
if ((len = adoptedRule->getAnteContextLength()) > maxContextLength) {
|
|
maxContextLength = len;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Close this rule set to further additions, check it for masked rules,
|
|
* and index it to optimize performance. Once this method is called,
|
|
* addRule() can no longer be called.
|
|
* @exception IllegalArgumentException if some rules are masked
|
|
*/
|
|
void TransliterationRuleSet::freeze(const TransliterationRuleData& data,
|
|
UErrorCode& status) {
|
|
if (U_FAILURE(status)) {
|
|
return;
|
|
}
|
|
|
|
/* Construct the rule array and index table. We reorder the
|
|
* rules by sorting them into 256 bins. Each bin contains all
|
|
* rules matching the index value for that bin. A rule
|
|
* matches an index value if string whose first key character
|
|
* has a low byte equal to the index value can match the rule.
|
|
*
|
|
* Each bin contains zero or more rules, in the same order
|
|
* they were found originally. However, the total rules in
|
|
* the bins may exceed the number in the original vector,
|
|
* since rules that have a variable as their first key
|
|
* character will generally fall into more than one bin.
|
|
*
|
|
* That is, each bin contains all rules that either have that
|
|
* first index value as their first key character, or have
|
|
* a set containing the index value as their first character.
|
|
*/
|
|
int32_t n = ruleVector->size();
|
|
int32_t j;
|
|
int16_t x;
|
|
UVector v(2*n); // heuristic; adjust as needed
|
|
|
|
/* Precompute the index values. This saves a LOT of time.
|
|
*/
|
|
int16_t* indexValue = new int16_t[n];
|
|
for (j=0; j<n; ++j) {
|
|
TransliterationRule* r = (TransliterationRule*) ruleVector->elementAt(j);
|
|
indexValue[j] = r->getIndexValue(data);
|
|
}
|
|
for (x=0; x<256; ++x) {
|
|
index[x] = v.size();
|
|
for (j=0; j<n; ++j) {
|
|
if (indexValue[j] >= 0) {
|
|
if (indexValue[j] == x) {
|
|
v.addElement(ruleVector->elementAt(j));
|
|
}
|
|
} else {
|
|
// If the indexValue is < 0, then the first key character is
|
|
// a set, and we must use the more time-consuming
|
|
// matchesIndexValue check. In practice this happens
|
|
// rarely, so we seldom tread this code path.
|
|
TransliterationRule* r = (TransliterationRule*) ruleVector->elementAt(j);
|
|
if (r->matchesIndexValue((uint8_t)x, data)) {
|
|
v.addElement(r);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
delete[] indexValue;
|
|
index[256] = v.size();
|
|
|
|
/* Freeze things into an array.
|
|
*/
|
|
rules = new TransliterationRule*[v.size()];
|
|
for (j=0; j<v.size(); ++j) {
|
|
rules[j] = (TransliterationRule*) v.elementAt(j);
|
|
}
|
|
delete ruleVector;
|
|
ruleVector = NULL;
|
|
|
|
// TODO Add error reporting that indicates the rules that
|
|
// are being masked.
|
|
//UnicodeString errors;
|
|
|
|
/* Check for masking. This is MUCH faster than our old check,
|
|
* which was each rule against each following rule, since we
|
|
* only have to check for masking within each bin now. It's
|
|
* 256*O(n2^2) instead of O(n1^2), where n1 is the total rule
|
|
* count, and n2 is the per-bin rule count. But n2<<n1, so
|
|
* it's a big win.
|
|
*/
|
|
for (x=0; x<256; ++x) {
|
|
for (j=index[x]; j<index[x+1]-1; ++j) {
|
|
TransliterationRule* r1 = rules[j];
|
|
for (int32_t k=j+1; k<index[x+1]; ++k) {
|
|
TransliterationRule* r2 = rules[k];
|
|
if (r1->masks(*r2)) {
|
|
//| if (errors == null) {
|
|
//| errors = new StringBuffer();
|
|
//| } else {
|
|
//| errors.append("\n");
|
|
//| }
|
|
//| errors.append("Rule " + r1 + " masks " + r2);
|
|
status = U_ILLEGAL_ARGUMENT_ERROR;
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
//if (errors != null) {
|
|
// throw new IllegalArgumentException(errors.toString());
|
|
//}
|
|
}
|
|
|
|
/**
|
|
* Attempt to find a matching rule at the specified point in the text.
|
|
* @param text the text, both translated and untranslated
|
|
* @param start the beginning index, inclusive; <code>0 <= start
|
|
* <= limit</code>.
|
|
* @param limit the ending index, exclusive; <code>start <= limit
|
|
* <= text.length()</code>.
|
|
* @param cursor position at which to translate next, representing offset
|
|
* into text. This value must be between <code>start</code> and
|
|
* <code>limit</code>.
|
|
* @param data a dictionary mapping variables to the sets they
|
|
* represent (maps <code>Character</code> to <code>UnicodeSet</code>)
|
|
* @param filter the filter. Any character for which
|
|
* <tt>filter.contains()</tt> returns <tt>false</tt> will not be
|
|
* altered by this transliterator. If <tt>filter</tt> is
|
|
* <tt>null</tt> then no filtering is applied.
|
|
* @return the matching rule, or null if none found.
|
|
*/
|
|
TransliterationRule*
|
|
TransliterationRuleSet::findMatch(const Replaceable& text,
|
|
int32_t start, int32_t limit,
|
|
int32_t cursor,
|
|
const TransliterationRuleData& data,
|
|
const UnicodeFilter* filter) const {
|
|
/* We only need to check our indexed bin of the rule table,
|
|
* based on the low byte of the first key character.
|
|
*/
|
|
int16_t x = text.charAt(cursor) & 0xFF;
|
|
for (int32_t i=index[x]; i<index[x+1]; ++i) {
|
|
if (rules[i]->matches(text, start, limit, cursor, data, filter)) {
|
|
return rules[i];
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/**
|
|
* Attempt to find a matching rule at the specified point in the text.
|
|
* Unlike <code>findMatch()</code>, this method does an incremental match.
|
|
* An incremental match requires that there be no partial matches that might
|
|
* pre-empt the full match that is found. If there are partial matches,
|
|
* then null is returned. A non-null result indicates that a full match has
|
|
* been found, and that it cannot be pre-empted by a partial match
|
|
* regardless of what additional text is added to the translation buffer.
|
|
* @param text the text, both translated and untranslated
|
|
* @param start the beginning index, inclusive; <code>0 <= start
|
|
* <= limit</code>.
|
|
* @param limit the ending index, exclusive; <code>start <= limit
|
|
* <= text.length()</code>.
|
|
* @param cursor position at which to translate next, representing offset
|
|
* into text. This value must be between <code>start</code> and
|
|
* <code>limit</code>.
|
|
* @param data a dictionary mapping variables to the sets they
|
|
* represent (maps <code>Character</code> to <code>UnicodeSet</code>)
|
|
* @param partial output parameter. <code>partial[0]</code> is set to
|
|
* true if a partial match is returned.
|
|
* @param filter the filter. Any character for which
|
|
* <tt>filter.contains()</tt> returns <tt>false</tt> will not be
|
|
* altered by this transliterator. If <tt>filter</tt> is
|
|
* <tt>null</tt> then no filtering is applied.
|
|
* @return the matching rule, or null if none found, or if the text buffer
|
|
* does not have enough text yet to unambiguously match a rule.
|
|
*/
|
|
TransliterationRule*
|
|
TransliterationRuleSet::findIncrementalMatch(const Replaceable& text,
|
|
int32_t start,
|
|
int32_t limit, int32_t cursor,
|
|
const TransliterationRuleData& data,
|
|
UBool& isPartial,
|
|
const UnicodeFilter* filter) const {
|
|
|
|
/* We only need to check our indexed bin of the rule table,
|
|
* based on the low byte of the first key character.
|
|
*/
|
|
isPartial = FALSE;
|
|
int16_t x = text.charAt(cursor) & 0xFF;
|
|
for (int32_t i=index[x]; i<index[x+1]; ++i) {
|
|
int32_t match = rules[i]->getMatchDegree(text, start, limit, cursor,
|
|
data, filter);
|
|
switch (match) {
|
|
case TransliterationRule::FULL_MATCH:
|
|
return rules[i];
|
|
case TransliterationRule::PARTIAL_MATCH:
|
|
isPartial = TRUE;
|
|
return NULL;
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|