Refactor WordIterator into base::BreakIterator....

base/i18n/break_iterator.cc

Index: base/i18n/break_iterator.cc
===================================================================
--- base/i18n/break_iterator.cc	(revision 0)
+++ base/i18n/break_iterator.cc	(revision 0)
@@ -0,0 +1,76 @@
+// Copyright (c) 2009 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 "base/logging.h"
+#include "unicode/ubrk.h"
+#include "unicode/uchar.h"
+#include "unicode/ustring.h"
+
+namespace base {
+
+const size_t npos = -1;
+
+BreakIterator::BreakIterator(const string16* str, BreakType break_type)
+    : iter_(NULL),
+      string_(str),
+      break_type_(break_type),
+      prev_(npos),
+      pos_(0) {
+}
+
+BreakIterator::~BreakIterator() {
+  if (iter_)
+    ubrk_close(iter_);
+}
+
+bool BreakIterator::Init() {
+  UErrorCode status = U_ZERO_ERROR;
+  UBreakIteratorType break_type;
+  switch (break_type_) {
+    case BREAK_WORD:
+      break_type = UBRK_WORD;
+      break;
+    case BREAK_SPACE:
+      break_type = UBRK_LINE;
+      break;
+    default:
+      NOTREACHED();
+      break_type = UBRK_LINE;
+  }
+  iter_ = ubrk_open(break_type, NULL,
+                    string_->data(), static_cast<int32_t>(string_->size()),
+                    &status);
+  if (U_FAILURE(status)) {
+    NOTREACHED() << "ubrk_open failed";
+    return false;
+  }
+  ubrk_first(iter_);  // Move the iterator to the beginning of the string.
+  return true;
+}
+
+bool BreakIterator::Advance() {
+  prev_ = pos_;
+  const int32_t pos = ubrk_next(iter_);
+  if (pos == UBRK_DONE) {
+    pos_ = npos;
+    return false;
+  } else {
+    pos_ = static_cast<size_t>(pos);
+    return true;
+  }
+}
+
+bool BreakIterator::IsWord() const {
+  return (break_type_ == BREAK_WORD &&
+          ubrk_getRuleStatus(iter_) != UBRK_WORD_NONE);
+}
+
+string16 BreakIterator::GetString() const {
+  DCHECK(prev_ != npos && pos_ != npos);
+  return string_->substr(prev_, pos_ - prev_);
+}
+
+}  // namespace base