blob: b99abcfb623de3f057c5243b697e907034bd3eb8 [file] [log] [blame]
// Copyright 2011 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/i18n/char_iterator.h"
#include "base/check_op.h"
#include "base/third_party/icu/icu_utf.h"
namespace base {
namespace i18n {
// UTF8CharIterator ------------------------------------------------------------
UTF8CharIterator::UTF8CharIterator(base::StringPiece str)
: str_(str), array_pos_(0), next_pos_(0), char_pos_(0), char_(0) {
if (!str_.empty())
CBU8_NEXT(str_.data(), next_pos_, str_.length(), char_);
}
UTF8CharIterator::~UTF8CharIterator() = default;
bool UTF8CharIterator::Advance() {
if (array_pos_ >= str_.length())
return false;
array_pos_ = next_pos_;
char_pos_++;
if (next_pos_ < str_.length())
CBU8_NEXT(str_.data(), next_pos_, str_.length(), char_);
return true;
}
// UTF16CharIterator -----------------------------------------------------------
UTF16CharIterator::UTF16CharIterator(StringPiece16 str)
: UTF16CharIterator(str, 0) {}
UTF16CharIterator::UTF16CharIterator(UTF16CharIterator&& to_move) = default;
UTF16CharIterator::~UTF16CharIterator() = default;
UTF16CharIterator& UTF16CharIterator::operator=(UTF16CharIterator&& to_move) =
default;
// static
UTF16CharIterator UTF16CharIterator::LowerBound(StringPiece16 str,
size_t array_index) {
DCHECK_LE(array_index, str.length());
CBU16_SET_CP_START(str.data(), 0, array_index);
return UTF16CharIterator(str, array_index);
}
// static
UTF16CharIterator UTF16CharIterator::UpperBound(StringPiece16 str,
size_t array_index) {
DCHECK_LE(array_index, str.length());
CBU16_SET_CP_LIMIT(str.data(), 0, array_index, str.length());
return UTF16CharIterator(str, array_index);
}
int32_t UTF16CharIterator::NextCodePoint() const {
if (next_pos_ >= str_.length())
return 0;
base_icu::UChar32 c;
CBU16_GET(str_.data(), 0, next_pos_, str_.length(), c);
return c;
}
int32_t UTF16CharIterator::PreviousCodePoint() const {
if (array_pos_ == 0)
return 0;
uint32_t pos = array_pos_;
base_icu::UChar32 c;
CBU16_PREV(str_.data(), 0, pos, c);
return c;
}
bool UTF16CharIterator::Advance() {
if (array_pos_ >= str_.length())
return false;
array_pos_ = next_pos_;
char_offset_++;
if (next_pos_ < str_.length())
ReadChar();
return true;
}
bool UTF16CharIterator::Rewind() {
if (array_pos_ == 0)
return false;
next_pos_ = array_pos_;
char_offset_--;
CBU16_PREV(str_.data(), 0, array_pos_, char_);
return true;
}
UTF16CharIterator::UTF16CharIterator(StringPiece16 str, size_t initial_pos)
: str_(str),
array_pos_(initial_pos),
next_pos_(initial_pos),
char_offset_(0),
char_(0) {
// This has the side-effect of advancing |next_pos_|.
if (array_pos_ < str_.length())
ReadChar();
}
void UTF16CharIterator::ReadChar() {
// This is actually a huge macro, so is worth having in a separate function.
CBU16_NEXT(str_.data(), next_pos_, str_.length(), char_);
}
} // namespace i18n
} // namespace base