September Morn Update

Task/String-length/Visual-Basic-.NET/string-length-2.visual

@@ -0,0 +1,20 @@
+Module CharacterLength
+    Function GetUTF16CodeUnitsLength(s As String) As Integer
+        Return s.Length
+    End Function
+
+    Private Function GetUTF16SurrogatePairCount(s As String) As Integer
+        GetUTF16SurrogatePairCount = 0
+        For i = 1 To s.Length - 1
+            If Char.IsSurrogatePair(s(i - 1), s(i)) Then GetUTF16SurrogatePairCount += 1
+        Next
+    End Function
+
+    Function GetCharacterLength_FromUTF16(s As String) As Integer
+        Return GetUTF16CodeUnitsLength(s) - GetUTF16SurrogatePairCount(s)
+    End Function
+
+    Function GetCharacterLength_FromUTF32(s As String) As Integer
+        Return GetByteLength(s, Text.Encoding.UTF32) \ 4
+    End Function
+End Module