naiveproxy/base/i18n/break_iterator.cc
2018-02-02 05:49:39 -05:00

192 lines
5.7 KiB
C++

// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/i18n/break_iterator.h"
#include <stdint.h>
#include "base/logging.h"
#include "third_party/icu/source/common/unicode/ubrk.h"
#include "third_party/icu/source/common/unicode/uchar.h"
#include "third_party/icu/source/common/unicode/ustring.h"
namespace base {
namespace i18n {
const size_t npos = static_cast<size_t>(-1);
BreakIterator::BreakIterator(const StringPiece16& str, BreakType break_type)
: iter_(nullptr),
string_(str),
break_type_(break_type),
prev_(npos),
pos_(0) {}
BreakIterator::BreakIterator(const StringPiece16& str, const string16& rules)
: iter_(nullptr),
string_(str),
rules_(rules),
break_type_(RULE_BASED),
prev_(npos),
pos_(0) {}
BreakIterator::~BreakIterator() {
if (iter_)
ubrk_close(static_cast<UBreakIterator*>(iter_));
}
bool BreakIterator::Init() {
UErrorCode status = U_ZERO_ERROR;
UParseError parse_error;
UBreakIteratorType break_type;
switch (break_type_) {
case BREAK_CHARACTER:
break_type = UBRK_CHARACTER;
break;
case BREAK_WORD:
break_type = UBRK_WORD;
break;
case BREAK_LINE:
case BREAK_NEWLINE:
case RULE_BASED: // (Keep compiler happy, break_type not used in this case)
break_type = UBRK_LINE;
break;
default:
NOTREACHED() << "invalid break_type_";
return false;
}
if (break_type_ == RULE_BASED) {
iter_ = ubrk_openRules(rules_.c_str(),
static_cast<int32_t>(rules_.length()),
string_.data(),
static_cast<int32_t>(string_.size()),
&parse_error,
&status);
if (U_FAILURE(status)) {
NOTREACHED() << "ubrk_openRules failed to parse rule string at line "
<< parse_error.line << ", offset " << parse_error.offset;
}
} else {
iter_ = ubrk_open(break_type, nullptr, string_.data(),
static_cast<int32_t>(string_.size()), &status);
if (U_FAILURE(status)) {
NOTREACHED() << "ubrk_open failed for type " << break_type
<< " with error " << status;
}
}
if (U_FAILURE(status)) {
return false;
}
// Move the iterator to the beginning of the string.
ubrk_first(static_cast<UBreakIterator*>(iter_));
return true;
}
bool BreakIterator::Advance() {
int32_t pos;
int32_t status;
prev_ = pos_;
switch (break_type_) {
case BREAK_CHARACTER:
case BREAK_WORD:
case BREAK_LINE:
case RULE_BASED:
pos = ubrk_next(static_cast<UBreakIterator*>(iter_));
if (pos == UBRK_DONE) {
pos_ = npos;
return false;
}
pos_ = static_cast<size_t>(pos);
return true;
case BREAK_NEWLINE:
do {
pos = ubrk_next(static_cast<UBreakIterator*>(iter_));
if (pos == UBRK_DONE)
break;
pos_ = static_cast<size_t>(pos);
status = ubrk_getRuleStatus(static_cast<UBreakIterator*>(iter_));
} while (status >= UBRK_LINE_SOFT && status < UBRK_LINE_SOFT_LIMIT);
if (pos == UBRK_DONE && prev_ == pos_) {
pos_ = npos;
return false;
}
return true;
default:
NOTREACHED() << "invalid break_type_";
return false;
}
}
bool BreakIterator::SetText(const base::char16* text, const size_t length) {
UErrorCode status = U_ZERO_ERROR;
ubrk_setText(static_cast<UBreakIterator*>(iter_),
text, length, &status);
pos_ = 0; // implicit when ubrk_setText is done
prev_ = npos;
if (U_FAILURE(status)) {
NOTREACHED() << "ubrk_setText failed";
return false;
}
string_ = StringPiece16(text, length);
return true;
}
bool BreakIterator::IsWord() const {
return GetWordBreakStatus() == IS_WORD_BREAK;
}
BreakIterator::WordBreakStatus BreakIterator::GetWordBreakStatus() const {
int32_t status = ubrk_getRuleStatus(static_cast<UBreakIterator*>(iter_));
if (break_type_ != BREAK_WORD && break_type_ != RULE_BASED)
return IS_LINE_OR_CHAR_BREAK;
// In ICU 60, trying to advance past the end of the text does not change
// |status| so that |pos_| has to be checked as well as |status|.
// See http://bugs.icu-project.org/trac/ticket/13447 .
return (status == UBRK_WORD_NONE || pos_ == npos) ? IS_SKIPPABLE_WORD
: IS_WORD_BREAK;
}
bool BreakIterator::IsEndOfWord(size_t position) const {
if (break_type_ != BREAK_WORD && break_type_ != RULE_BASED)
return false;
UBreakIterator* iter = static_cast<UBreakIterator*>(iter_);
UBool boundary = ubrk_isBoundary(iter, static_cast<int32_t>(position));
int32_t status = ubrk_getRuleStatus(iter);
return (!!boundary && status != UBRK_WORD_NONE);
}
bool BreakIterator::IsStartOfWord(size_t position) const {
if (break_type_ != BREAK_WORD && break_type_ != RULE_BASED)
return false;
UBreakIterator* iter = static_cast<UBreakIterator*>(iter_);
UBool boundary = ubrk_isBoundary(iter, static_cast<int32_t>(position));
ubrk_next(iter);
int32_t next_status = ubrk_getRuleStatus(iter);
return (!!boundary && next_status != UBRK_WORD_NONE);
}
bool BreakIterator::IsGraphemeBoundary(size_t position) const {
if (break_type_ != BREAK_CHARACTER)
return false;
UBreakIterator* iter = static_cast<UBreakIterator*>(iter_);
return !!ubrk_isBoundary(iter, static_cast<int32_t>(position));
}
string16 BreakIterator::GetString() const {
return GetStringPiece().as_string();
}
StringPiece16 BreakIterator::GetStringPiece() const {
DCHECK(prev_ != npos && pos_ != npos);
return string_.substr(prev_, pos_ - prev_);
}
} // namespace i18n
} // namespace base