add middle dot in hashtag

lib/TwitterText.m

@@ -53,6 +53,16 @@
 //
 // Hashtag
 //
+#define TWUMiddleDot                    @"\\u00B7"
+#define TWUBullet                       @"\\u2022"
+#define TWUKatakanaMiddleDot            @"\\u30FB"
+#define TWUHalfwidthKatakanaMiddleDot   @"\\uff65"
+
+#define TWUSpecialCharsIncluded \
+    TWUMiddleDot \
+    TWUBullet \
+    TWUKatakanaMiddleDot \
+    TWUHalfwidthKatakanaMiddleDot
 
 #define TWUCyrillicHashtagChars                     @"\\u0400-\\u04FF"
 #define TWUCyrillicSupplementHashtagChars           @"\\u0500-\\u0527"
@@ -137,6 +147,7 @@
     TWULatinAccents \
     TWUNonLatinHashtagChars \
     TWUCJKHashtagCharacters \
+    TWUSpecialCharsIncluded \
 @"]"
 
 #define TWUHashtagBoundaryInvalidChars \

test/json-conformance/extract.json

@@ -1167,6 +1167,13 @@
       }
     ],
     "hashtags": [
+      {
+        "description": "Extract mid-dot hashtag",
+        "text": "a #ビ·ル•ゲ・イ･ツ",
+        "expected": [
+          "ビ·ル•ゲ・イ･ツ"
+        ]
+      },
       {
         "description": "Extract an all-alpha hashtag",
         "text": "a #hashtag here",