Bug 208789 - patch 1 - Create an intl::GeneralCategory enum for UnicodeProperties::CharType() to return, to avoid directly referring to ICU4C constants or mapping via harfbuzz constants. r=platform-i18n-reviewers,nordzilla

No change in behavior; this just gives us our own version of the general category constants,
so we can avoid depending on ICU's constants elsewhere in the codebase.

Differential Revision: https://phabricator.services.mozilla.com/D173203

intl/components/moz.build

@@ -16,6 +16,7 @@ EXPORTS.mozilla.intl = [
     "src/DateTimePatternGenerator.h",
     "src/DisplayNames.h",
     "src/FormatBuffer.h",
+    "src/GeneralCategory.h",
     "src/ICU4CGlue.h",
     "src/ICU4CLibrary.h",
     "src/ICUError.h",

intl/components/src/GeneralCategory.h

@@ -0,0 +1,52 @@
+/* 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/. */
+#ifndef intl_components_GeneralCategory_h_
+#define intl_components_GeneralCategory_h_
+
+#include <cstdint>
+
+namespace mozilla::intl {
+
+// See https://www.unicode.org/reports/tr44/#General_Category_Values
+// for details of these values.
+
+// The values here must match the values used by ICU's UCharCategory.
+
+enum class GeneralCategory : uint8_t {
+  Unassigned = 0,
+  Uppercase_Letter = 1,
+  Lowercase_Letter = 2,
+  Titlecase_Letter = 3,
+  Modifier_Letter = 4,
+  Other_Letter = 5,
+  Nonspacing_Mark = 6,
+  Enclosing_Mark = 7,
+  Spacing_Mark = 8,
+  Decimal_Number = 9,
+  Letter_Number = 10,
+  Other_Number = 11,
+  Space_Separator = 12,
+  Line_Separator = 13,
+  Paragraph_Separator = 14,
+  Control = 15,
+  Format = 16,
+  Private_Use = 17,
+  Surrogate = 18,
+  Dash_Punctuation = 19,
+  Open_Punctuation = 20,
+  Close_Punctuation = 21,
+  Connector_Punctuation = 22,
+  Other_Punctuation = 23,
+  Math_Symbol = 24,
+  Currency_Symbol = 25,
+  Modifier_Symbol = 26,
+  Other_Symbol = 27,
+  Initial_Punctuation = 28,
+  Final_Punctuation = 29,
+  GeneralCategoryCount
+};
+
+}  // namespace mozilla::intl
+
+#endif

intl/components/src/UnicodeProperties.h

@@ -5,6 +5,7 @@
 #define intl_components_UnicodeProperties_h_
 
 #include "mozilla/intl/BidiClass.h"
+#include "mozilla/intl/GeneralCategory.h"
 #include "mozilla/intl/ICU4CGlue.h"
 #include "mozilla/intl/UnicodeScriptCodes.h"
 #include "mozilla/Vector.h"
@@ -34,7 +35,9 @@ class UnicodeProperties final {
   /**
    * Return the general category value for the code point.
    */
-  static inline uint32_t CharType(uint32_t aCh) { return u_charType(aCh); }
+  static inline GeneralCategory CharType(uint32_t aCh) {
+    return GeneralCategory(u_charType(aCh));
+  }
 
   /**
    * Determine whether the code point has the Bidi_Mirrored property.
@@ -222,7 +225,8 @@ class UnicodeProperties final {
    */
   static inline bool IsMathOrMusicSymbol(uint32_t aCh) {
     // Keep this function in sync with is_math_symbol in base_chars.py.
-    return CharType(aCh) == U_MATH_SYMBOL || CharType(aCh) == U_OTHER_SYMBOL;
+    return CharType(aCh) == GeneralCategory::Math_Symbol ||
+           CharType(aCh) == GeneralCategory::Other_Symbol;
   }
 
   static inline Script GetScriptCode(uint32_t aCh) {

intl/unicharutil/util/nsUnicodeProperties.h

@@ -64,8 +64,11 @@ const uint32_t kEmojiSkinToneLast = 0x1f3ff;
 
 extern const hb_unicode_general_category_t sICUtoHBcategory[];
 
+// NOTE: This returns values matching harfbuzz HB_UNICODE_GENERAL_CATEGORY_*
+// constants, NOT the mozilla::intl::GeneralCategory enum.
+// For the GeneralCategory enum, use intl::UnicodeProperties::CharType itself.
 inline uint8_t GetGeneralCategory(uint32_t aCh) {
-  return sICUtoHBcategory[intl::UnicodeProperties::CharType(aCh)];
+  return sICUtoHBcategory[unsigned(intl::UnicodeProperties::CharType(aCh))];
 }
 
 inline int8_t GetNumericValue(uint32_t aCh) {