1 files changed, 185 insertions, 0 deletions
diff --git a/intl/lwbrk/WordBreaker.cpp b/intl/lwbrk/WordBreaker.cpp
new file mode 100644
index 0000000000..f7fc10a7a1
--- /dev/null
+++ b/intl/lwbrk/WordBreaker.cpp
@@ -0,0 +1,185 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/intl/UnicodeProperties.h"
+#include "mozilla/intl/WordBreaker.h"
+#include "mozilla/StaticPrefs_layout.h"
+#include "nsComplexBreaker.h"
+#include "nsTArray.h"
+#include "nsUnicodeProperties.h"
+
+using mozilla::intl::Script;
+using mozilla::intl::UnicodeProperties;
+using mozilla::intl::WordBreaker;
+using mozilla::intl::WordRange;
+using mozilla::unicode::GetGenCategory;
+
+#define IS_ASCII(c) (0 == (0xFF80 & (c)))
+#define ASCII_IS_ALPHA(c) \
+  ((('a' <= (c)) && ((c) <= 'z')) || (('A' <= (c)) && ((c) <= 'Z')))
+#define ASCII_IS_DIGIT(c) (('0' <= (c)) && ((c) <= '9'))
+#define ASCII_IS_SPACE(c) \
+  ((' ' == (c)) || ('\t' == (c)) || ('\r' == (c)) || ('\n' == (c)))
+#define IS_ALPHABETICAL_SCRIPT(c) ((c) < 0x2E80)
+
+// we change the beginning of IS_HAN from 0x4e00 to 0x3400 to relfect
+// Unicode 3.0
+#define IS_HAN(c) \
+  ((0x3400 <= (c)) && ((c) <= 0x9fff)) || ((0xf900 <= (c)) && ((c) <= 0xfaff))
+#define IS_KATAKANA(c) ((0x30A0 <= (c)) && ((c) <= 0x30FF))
+#define IS_HIRAGANA(c) ((0x3040 <= (c)) && ((c) <= 0x309F))
+#define IS_HALFWIDTHKATAKANA(c) ((0xFF60 <= (c)) && ((c) <= 0xFF9F))
+
+// Return true if aChar belongs to a SEAsian script that is written without
+// word spaces, so we need to use the "complex breaker" to find possible word
+// boundaries. (https://en.wikipedia.org/wiki/Scriptio_continua)
+// (How well this works depends on the level of platform support for finding
+// possible line breaks - or possible word boundaries - in the particular
+// script. Thai, at least, works pretty well on the major desktop OSes. If
+// the script is not supported by the platform, we just won't find any useful
+// boundaries.)
+static bool IsScriptioContinua(char16_t aChar) {
+  Script sc = UnicodeProperties::GetScriptCode(aChar);
+  return sc == Script::THAI || sc == Script::MYANMAR || sc == Script::KHMER ||
+         sc == Script::JAVANESE || sc == Script::BALINESE ||
+         sc == Script::SUNDANESE || sc == Script::LAO;
+}
+
+/* static */
+WordBreaker::WordBreakClass WordBreaker::GetClass(char16_t c) {
+  // begin of the hack
+
+  if (IS_ALPHABETICAL_SCRIPT(c)) {
+    if (IS_ASCII(c)) {
+      if (ASCII_IS_SPACE(c)) {
+        return kWbClassSpace;
+      }
+      if (ASCII_IS_ALPHA(c) || ASCII_IS_DIGIT(c) ||
+          (c == '_' && !StaticPrefs::layout_word_select_stop_at_underscore())) {
+        return kWbClassAlphaLetter;
+      }
+      return kWbClassPunct;
+    }
+    if (c == 0x00A0 /*NBSP*/) {
+      return kWbClassSpace;
+    }
+    if (GetGenCategory(c) == nsUGenCategory::kPunctuation) {
+      return kWbClassPunct;
+    }
+    if (IsScriptioContinua(c)) {
+      return kWbClassScriptioContinua;
+    }
+    return kWbClassAlphaLetter;
+  }
+  if (IS_HAN(c)) {
+    return kWbClassHanLetter;
+  }
+  if (IS_KATAKANA(c)) {
+    return kWbClassKatakanaLetter;
+  }
+  if (IS_HIRAGANA(c)) {
+    return kWbClassHiraganaLetter;
+  }
+  if (IS_HALFWIDTHKATAKANA(c)) {
+    return kWbClassHWKatakanaLetter;
+  }
+  if (GetGenCategory(c) == nsUGenCategory::kPunctuation) {
+    return kWbClassPunct;
+  }
+  if (IsScriptioContinua(c)) {
+    return kWbClassScriptioContinua;
+  }
+  return kWbClassAlphaLetter;
+}
+
+WordRange WordBreaker::FindWord(const char16_t* aText, uint32_t aLen,
+                                uint32_t aPos) {
+  MOZ_ASSERT(aText);
+
+  if (aPos >= aLen) {
+    return {aLen, aLen};
+  }
+
+  WordBreakClass c = GetClass(aText[aPos]);
+  WordRange range{0, aLen};
+
+  // Scan forward
+  for (uint32_t i = aPos + 1; i <= aLen; i++) {
+    if (c != GetClass(aText[i])) {
+      range.mEnd = i;
+      break;
+    }
+  }
+
+  // Scan backward
+  for (uint32_t i = aPos; i > 0; i--) {
+    if (c != GetClass(aText[i - 1])) {
+      range.mBegin = i;
+      break;
+    }
+  }
+
+  if (kWbClassScriptioContinua == c) {
+    // we pass the whole text segment to the complex word breaker to find a
+    // shorter answer
+    AutoTArray<uint8_t, 256> breakBefore;
+    breakBefore.SetLength(range.mEnd - range.mBegin);
+    ComplexBreaker::GetBreaks(aText + range.mBegin, range.mEnd - range.mBegin,
+                              breakBefore.Elements());
+
+    // Scan forward
+    for (uint32_t i = aPos + 1; i < range.mEnd; i++) {
+      if (breakBefore[i - range.mBegin]) {
+        range.mEnd = i;
+        break;
+      }
+    }
+
+    // Scan backward
+    for (uint32_t i = aPos; i > range.mBegin; i--) {
+      if (breakBefore[i - range.mBegin]) {
+        range.mBegin = i;
+        break;
+      }
+    }
+  }
+  return range;
+}
+
+int32_t WordBreaker::Next(const char16_t* aText, uint32_t aLen, uint32_t aPos) {
+  MOZ_ASSERT(aText);
+
+  if (aPos >= aLen) {
+    return NS_WORDBREAKER_NEED_MORE_TEXT;
+  }
+
+  const WordBreakClass posClass = GetClass(aText[aPos]);
+  uint32_t nextBreakPos;
+  for (nextBreakPos = aPos + 1; nextBreakPos < aLen; ++nextBreakPos) {
+    if (posClass != GetClass(aText[nextBreakPos])) {
+      break;
+    }
+  }
+
+  if (kWbClassScriptioContinua == posClass) {
+    // We pass the whole text segment to the complex word breaker to find a
+    // shorter answer.
+    const char16_t* segStart = aText + aPos;
+    const uint32_t segLen = nextBreakPos - aPos + 1;
+    AutoTArray<uint8_t, 256> breakBefore;
+    breakBefore.SetLength(segLen);
+    ComplexBreaker::GetBreaks(segStart, segLen, breakBefore.Elements());
+
+    for (uint32_t i = aPos + 1; i < nextBreakPos; ++i) {
+      if (breakBefore[i - aPos]) {
+        nextBreakPos = i;
+        break;
+      }
+    }
+  }
+
+  MOZ_ASSERT(nextBreakPos != aPos);
+  return nextBreakPos;
+}