/*
**********************************************************************
* Copyright (C) 1999-2007, International Business Machines
* Corporation and others. All Rights Reserved.
**********************************************************************
* Date Name Description
* 11/17/99 aliu Creation.
**********************************************************************
*/
#include "unicode/utypes.h"
#if !UCONFIG_NO_TRANSLITERATION
#include "unicode/rep.h"
#include "unicode/unifilt.h"
#include "unicode/uniset.h"
#include "rbt_rule.h"
#include "rbt_data.h"
#include "cmemory.h"
#include "strmatch.h"
#include "strrepl.h"
#include "util.h"
#include "putilimp.h"
static const UChar FORWARD_OP[] = {32,62,32,0}; // " > "
U_NAMESPACE_BEGIN
/**
* Construct a new rule with the given input, output text, and other
* attributes. A cursor position may be specified for the output text.
* @param input input string, including key and optional ante and
* post context
* @param anteContextPos offset into input to end of ante context, or -1 if
* none. Must be <= input.length() if not -1.
* @param postContextPos offset into input to start of post context, or -1
* if none. Must be <= input.length() if not -1, and must be >=
* anteContextPos.
* @param output output string
* @param cursorPosition offset into output at which cursor is located, or -1 if
* none. If less than zero, then the cursor is placed after the
* <code>output</code>; that is, -1 is equivalent to
* <code>output.length()</code>. If greater than
* <code>output.length()</code> then an exception is thrown.
* @param segs array of UnicodeFunctors corresponding to input pattern
* segments, or null if there are none. The array itself is adopted,
* but the pointers within it are not.
* @param segsCount number of elements in segs[]
* @param anchorStart TRUE if the the rule is anchored on the left to
* the context start
* @param anchorEnd TRUE if the rule is anchored on the right to the
* context limit
*/
TransliterationRule::TransliterationRule(const UnicodeString& input,
int32_t anteContextPos, int32_t postContextPos,
const UnicodeString& outputStr,
int32_t cursorPosition, int32_t cursorOffset,
UnicodeFunctor** segs,
int32_t segsCount,
UBool anchorStart, UBool anchorEnd,
const TransliterationRuleData* theData,
UErrorCode& status) :
UMemory(),
segments(0),
data(theData) {
if (U_FAILURE(status)) {
return;
}
// Do range checks only when warranted to save time
if (anteContextPos < 0) {
anteContextLength = 0;
} else {
if (anteContextPos > input.length()) {
// throw new IllegalArgumentException("Invalid ante context");
status = U_ILLEGAL_ARGUMENT_ERROR;
return;
}
anteContextLength = anteContextPos;
}
if (postContextPos < 0) {
keyLength = input.length() - anteContextLength;
} else {
if (postContextPos < anteContextLength ||
postContextPos > input.length()) {
// throw new IllegalArgumentException("Invalid post context");
status = U_ILLEGAL_ARGUMENT_ERROR;
return;
}
keyLength = postContextPos - anteContextLength;
}
if (cursorPosition < 0) {
cursorPosition = outputStr.length();
} else if (cursorPosition > outputStr.length()) {
// throw new IllegalArgumentException("Invalid cursor position");
status = U_ILLEGAL_ARGUMENT_ERROR;
return;
}
// We don't validate the segments array. The caller must
// guarantee that the segments are well-formed (that is, that
// all $n references in the output refer to indices of this
// array, and that no array elements are null).
this->segments = segs;
this->segmentsCount = segsCount;
pattern = input;
flags = 0;
if (anchorStart) {
flags |= ANCHOR_START;
}
if (anchorEnd) {
flags |= ANCHOR_END;
}
anteContext = NULL;
if (anteContextLength > 0) {
anteContext = new StringMatcher(pattern, 0, anteContextLength,
FALSE, *data);
/* test for NULL */
if (anteContext == 0) {
status = U_MEMORY_ALLOCATION_ERROR;
return;
}
}
key = NULL;
if (keyLength > 0) {
key = new StringMatcher(pattern, anteContextLength, anteContextLength + keyLength,
FALSE, *data);
/* test for NULL */
if (key == 0) {
status = U_MEMORY_ALLOCATION_ERROR;
return;
}
}
int32_t postContextLength = pattern.length() - keyLength - anteContextLength;
postContext = NULL;
if (postContextLength > 0) {
postContext = new StringMatcher(pattern, anteContextLength + keyLength, pattern.length(),
FALSE, *data);
/* test for NULL */
if (postContext == 0) {
status = U_MEMORY_ALLOCATION_ERROR;
return;
}
}
this->output = new StringReplacer(outputStr, cursorPosition + cursorOffset, data);
/* test for NULL */
if (this->output == 0) {
status = U_MEMORY_ALLOCATION_ERROR;
return;
}
}
/**
* Copy constructor.
*/
TransliterationRule::TransliterationRule(TransliterationRule& other) :
UMemory(other),
anteContext(NULL),
key(NULL),
postContext(NULL),
pattern(other.pattern),
anteContextLength(other.anteContextLength),
keyLength(other.keyLength),
flags(other.flags),
data(other.data) {
segments = NULL;
segmentsCount = 0;
if (other.segmentsCount > 0) {
segments = (UnicodeFunctor **)uprv_malloc(other.segmentsCount * sizeof(UnicodeFunctor *));
uprv_memcpy(segments, other.segments, other.segmentsCount*sizeof(segments[0]));
}
if (other.anteContext != NULL) {
anteContext = (StringMatcher*) other.anteContext->clone();
}
if (other.key != NULL) {
key = (StringMatcher*) other.key->clone();
}
if (other.postContext != NULL) {
postContext = (StringMatcher*) other.postContext->clone();
}
output = other.output->clone();
}
TransliterationRule::~TransliterationRule() {
uprv_free(segments);
delete anteContext;
delete key;
delete postContext;
delete output;
}
/**
* Return the preceding context length. This method is needed to
* support the <code>Transliterator</code> method
* <code>getMaximumContextLength()</code>. Internally, this is
* implemented as the anteContextLength, optionally plus one if
* there is a start anchor. The one character anchor gap is
* needed to make repeated incremental transliteration with
* anchors work.
*/
int32_t TransliterationRule::getContextLength(void) const {
return anteContextLength + ((flags & ANCHOR_START) ? 1 : 0);
}
/**
* Internal method. Returns 8-bit index value for this rule.
* This is the low byte of the first character of the key,
* unless the first character of the key is a set. If it's a
* set, or otherwise can match multiple keys, the index value is -1.
*/
int16_t TransliterationRule::getIndexValue() const {
if (anteContextLength == pattern.length()) {
// A pattern with just ante context {such as foo)>bar} can
// match any key.
return -1;
}
UChar32 c = pattern.char32At(anteContextLength);
return (int16_t)(data->lookupMatcher(c) == NULL ? (c & 0xFF) : -1);
}
/**
* Internal method. Returns true if this rule matches the given
* index value. The index value is an 8-bit integer, 0..255,
* representing the low byte of the first character of the key.
* It matches this rule if it matches the first character of the
* key, or if the first character of the key is a set, and the set
* contains any character with a low byte equal to the index
* value. If the rule contains only ante context, as in foo)>bar,
* then it will match any key.
*/
UBool TransliterationRule::matchesIndexValue(uint8_t v) const {
// Delegate to the key, or if there is none, to the postContext.
// If there is neither then we match any key; return true.
UnicodeMatcher *m = (key != NULL) ? key : postContext;
return (m != NULL) ? m->matchesIndexValue(v) : TRUE;
}
/**
* Return true if this rule masks another rule. If r1 masks r2 then
* r1 matches any input string that r2 matches. If r1 masks r2 and r2 masks
* r1 then r1 == r2. Examples: "a>x" masks "ab>y". "a>x" masks "a[b]>y".
* "[c]a>x" masks "[dc]a>y".
*/
UBool TransliterationRule::masks(const TransliterationRule& r2) const {
/* Rule r1 masks rule r2 if the string formed of the
* antecontext, key, and postcontext overlaps in the following
* way:
*
* r1: aakkkpppp
* r2: aaakkkkkpppp
* ^
*
* The strings must be aligned at the first character of the
* key. The length of r1 to the left of the alignment point
* must be <= the length of r2 to the left; ditto for the
* right. The characters of r1 must equal (or be a superset
* of) the corresponding characters of r2. The superset
* operation should be performed to check for UnicodeSet
* masking.
*
* Anchors: Two patterns that differ only in anchors only
* mask one another if they are exactly equal, and r2 has
* all the anchors r1 has (optionally, plus some). Here Y
* means the row masks the column, N means it doesn't.
*
* ab ^ab ab$ ^ab$
* ab Y Y Y Y
* ^ab N Y N Y
* ab$ N N Y Y
* ^ab$ N N N Y
*
* Post context: {a}b masks ab, but not vice versa, since {a}b
* matches everything ab matches, and {a}b matches {|a|}b but ab
* does not. Pre context is different (a{b} does not align with
* ab).
*/
/* LIMITATION of the current mask algorithm: Some rule
* maskings are currently not detected. For example,
* "{Lu}]a>x" masks "A]a>y". This can be added later. TODO
*/
int32_t len = pattern.length();
int32_t left = anteContextLength;
int32_t left2 = r2.anteContextLength;
int32_t right = len - left;
int32_t right2 = r2.pattern.length() - left2;
int32_t cachedCompare = r2.pattern.compare(left2 - left, len, pattern);
// TODO Clean this up -- some logic might be combinable with the
// next statement.
// Test for anchor masking
if (left == left2 && right == right2 &&
keyLength <= r2.keyLength &&
0 == cachedCompare) {
// The following boolean logic implements the table above
return (flags == r2.flags) ||
(!(flags & ANCHOR_START) && !(flags & ANCHOR_END)) ||
((r2.flags & ANCHOR_START) && (r2.flags & ANCHOR_END));
}
return left <= left2 &&
(right < right2 ||
(right == right2 && keyLength <= r2.keyLength)) &&
(0 == cachedCompare);
}
static inline int32_t posBefore(const Replaceable& str, int32_t pos) {
return (pos > 0) ?
pos - UTF_CHAR_LENGTH(str.char32At(pos-1)) :
pos - 1;
}
static inline int32_t posAfter(const Replaceable& str, int32_t pos) {
return (pos >= 0 && pos < str.length()) ?
pos + UTF_CHAR_LENGTH(str.char32At(pos)) :
pos + 1;
}
/**
* Attempt a match and replacement at the given position. Return
* the degree of match between this rule and the given text. The
* degree of match may be mismatch, a partial match, or a full
* match. A mismatch means at least one character of the text
* does not match the context or key. A partial match means some
* context and key characters match, but the text is not long
* enough to match all of them. A full match means all context
* and key characters match.
*
* If a full match is obtained, perform a replacement, update pos,
* and return U_MATCH. Otherwise both text and pos are unchanged.
*
* @param text the text
* @param pos the position indices
* @param incremental if TRUE, test for partial matches that may
* be completed by additional text inserted at pos.limit.
* @return one of <code>U_MISMATCH</code>,
* <code>U_PARTIAL_MATCH</code>, or <code>U_MATCH</code>. If
* incremental is FALSE then U_PARTIAL_MATCH will not be returned.
*/
UMatchDegree TransliterationRule::matchAndReplace(Replaceable& text,
UTransPosition& pos,
UBool incremental) const {
// Matching and replacing are done in one method because the
// replacement operation needs information obtained during the
// match. Another way to do this is to have the match method
// create a match result struct with relevant offsets, and to pass
// this into the replace method.
// ============================ MATCH ===========================
// Reset segment match data
if (segments != NULL) {
for (int32_t i=0; i<segmentsCount; ++i) {
((StringMatcher*) segments[i])->resetMatch();
}
}
// int32_t lenDelta, keyLimit;
int32_t keyLimit;
// ------------------------ Ante Context ------------------------
// A mismatch in the ante context, or with the start anchor,
// is an outright U_MISMATCH regardless of whether we are
// incremental or not.
int32_t oText; // offset into 'text'
// int32_t newStart = 0;
int32_t minOText;
// Note (1): We process text in 16-bit code units, rather than
// 32-bit code points. This works because stand-ins are
// always in the BMP and because we are doing a literal match
// operation, which can be done 16-bits at a time.
int32_t anteLimit = posBefore(text, pos.contextStart);
UMatchDegree match;
// Start reverse match at char before pos.start
oText = posBefore(text, pos.start);
if (anteContext != NULL) {
match = anteContext->matches(text, oText, anteLimit, FALSE);
if (match != U_MATCH) {
return U_MISMATCH;
}
}
minOText = posAfter(text, oText);
// ------------------------ Start Anchor ------------------------
if (((flags & ANCHOR_START) != 0) && oText != anteLimit) {
return U_MISMATCH;
}
// -------------------- Key and Post Context --------------------
oText = pos.start;
if (key != NULL) {
match = key->matches(text, oText, pos.limit, incremental);
if (match != U_MATCH) {
return match;
}
}
keyLimit = oText;
if (postContext != NULL) {
if (incremental && keyLimit == pos.limit) {
// The key matches just before pos.limit, and there is
// a postContext. Since we are in incremental mode,
// we must assume more characters may be inserted at
// pos.limit -- this is a partial match.
return U_PARTIAL_MATCH;
}
match = postContext->matches(text, oText, pos.contextLimit, incremental);
if (match != U_MATCH) {
return match;
}
}
// ------------------------- Stop Anchor ------------------------
if (((flags & ANCHOR_END)) != 0) {
if (oText != pos.contextLimit) {
return U_MISMATCH;
}
if (incremental) {
return U_PARTIAL_MATCH;
}
}
// =========================== REPLACE ==========================
// We have a full match. The key is between pos.start and
// keyLimit.
int32_t newStart;
int32_t newLength = output->toReplacer()->replace(text, pos.start, keyLimit, newStart);
int32_t lenDelta = newLength - (keyLimit - pos.start);
oText += lenDelta;
pos.limit += lenDelta;
pos.contextLimit += lenDelta;
// Restrict new value of start to [minOText, min(oText, pos.limit)].
pos.start = uprv_max(minOText, uprv_min(uprv_min(oText, pos.limit), newStart));
return U_MATCH;
}
/**
* Create a source string that represents this rule. Append it to the
* given string.
*/
UnicodeString& TransliterationRule::toRule(UnicodeString& rule,
UBool escapeUnprintable) const {
// Accumulate special characters (and non-specials following them)
// into quoteBuf. Append quoteBuf, within single quotes, when
// a non-quoted element must be inserted.
UnicodeString str, quoteBuf;
// Do not emit the braces '{' '}' around the pattern if there
// is neither anteContext nor postContext.
UBool emitBraces =
(anteContext != NULL) || (postContext != NULL);
// Emit start anchor
if ((flags & ANCHOR_START) != 0) {
rule.append((UChar)94/*^*/);
}
// Emit the input pattern
ICU_Utility::appendToRule(rule, anteContext, escapeUnprintable, quoteBuf);
if (emitBraces) {
ICU_Utility::appendToRule(rule, (UChar) 0x007B /*{*/, TRUE, escapeUnprintable, quoteBuf);
}
ICU_Utility::appendToRule(rule, key, escapeUnprintable, quoteBuf);
if (emitBraces) {
ICU_Utility::appendToRule(rule, (UChar) 0x007D /*}*/, TRUE, escapeUnprintable, quoteBuf);
}
ICU_Utility::appendToRule(rule, postContext, escapeUnprintable, quoteBuf);
// Emit end anchor
if ((flags & ANCHOR_END) != 0) {
rule.append((UChar)36/*$*/);
}
ICU_Utility::appendToRule(rule, FORWARD_OP, TRUE, escapeUnprintable, quoteBuf);
// Emit the output pattern
ICU_Utility::appendToRule(rule, output->toReplacer()->toReplacerPattern(str, escapeUnprintable),
TRUE, escapeUnprintable, quoteBuf);
ICU_Utility::appendToRule(rule, (UChar) 0x003B /*;*/, TRUE, escapeUnprintable, quoteBuf);
return rule;
}
void TransliterationRule::setData(const TransliterationRuleData* d) {
data = d;
if (anteContext != NULL) anteContext->setData(d);
if (postContext != NULL) postContext->setData(d);
if (key != NULL) key->setData(d);
// assert(output != NULL);
output->setData(d);
// Don't have to do segments since they are in the context or key
}
/**
* Union the set of all characters that may be modified by this rule
* into the given set.
*/
void TransliterationRule::addSourceSetTo(UnicodeSet& toUnionTo) const {
int32_t limit = anteContextLength + keyLength;
for (int32_t i=anteContextLength; i<limit; ) {
UChar32 ch = pattern.char32At(i);
i += UTF_CHAR_LENGTH(ch);
const UnicodeMatcher* matcher = data->lookupMatcher(ch);
if (matcher == NULL) {
toUnionTo.add(ch);
} else {
matcher->addMatchSetTo(toUnionTo);
}
}
}
/**
* Union the set of all characters that may be emitted by this rule
* into the given set.
*/
void TransliterationRule::addTargetSetTo(UnicodeSet& toUnionTo) const {
output->toReplacer()->addReplacementSetTo(toUnionTo);
}
U_NAMESPACE_END
#endif /* #if !UCONFIG_NO_TRANSLITERATION */
//eof