正規化

更新 : 2007 年 11 月

一部の Unicode 文字は、一連の Unicode 文字を組み合わせたり合成したりすることによって、複数のバイナリ形式で表現できます。1 つの文字を複数の形式で表現すると、文字の検索、並べ替え、照合などの操作が複雑になります。

Unicode 規格では、ある文字をいずれかのバイナリ表現で渡すと、特定の 1 つのバイナリ表現にして返す、正規化と呼ばれる処理が定義されています。正規化では、それぞれ異なる規則に基づく複数のアルゴリズムを使用できます。これらは正規化形式と呼ばれます。.NET Framework では、現在、C、D、KC および KD という Unicode 正規化形式がサポートされています。

メモ :
同じ正規化形式に従って正規化された 2 つの文字列は、通常の比較処理、つまり文字ごとのバイナリ比較を使用して比較できます。

.NET Framework でサポートされている正規化形式の詳細については、「NormalizationForm」を参照してください。正規化、文字の分解、および等値の詳細については、Unicode ホーム サイト にある「Unicode Standard Annex #15」の「Unicode Normalization Forms」を参照してください。

文字列の正規化

アプリケーションでは、String オブジェクトの String.Normalize メソッドを使用して、既定で正規化形式 C に正規化された新しい文字列を返す必要があります。また、String オブジェクトの String.Normalize メソッドを使用し、NormalizationForm 値を指定して、正規化形式 C、D、KC、または KD に明確に正規化された新しい文字列を返すこともできます。

文字列が正規化されているかどうかの確認

アプリケーションで String オブジェクトの String.IsNormalized メソッドを使用することにより、このオブジェクトの文字列値が正規化形式 C に正規化されていることを確認できます。また、String オブジェクトの String.IsNormalized メソッドを使用し、NormalizationForm に特定の値を指定することにより、このオブジェクトの文字列値が正規化形式 C、D、KC、または KD に明確に正規化されていることを確認することもできます。

例

IsNormalized メソッドおよび Normalize メソッドのコード例を次に示します。このコード例では、元の文字列が 4 つの正規化形式のいずれかであるかどうかをテストした後、それぞれの正規化形式で元の文字列を作成します。そして、正規化した各文字列が目的の正規化形式で正規化されているかどうかをテストし、正規化された文字列の各文字のコード ポイントを 16 進で表示します。

' This example demonstrates the String.Normalize method
'                       and the String.IsNormalized method
Imports System
Imports System.Text
Imports Microsoft.VisualBasic

Class Sample
   Public Shared Sub Main()
      ' Character c; combining characters acute and cedilla; character 3/4
      Dim s1 = New [String](New Char() {ChrW(&H0063), ChrW(&H0301), ChrW(&H0327), ChrW(&H00BE)})
      Dim s2 As String = Nothing
      Dim divider = New [String]("-"c, 80)
      divider = [String].Concat(Environment.NewLine, divider, Environment.NewLine)

      Try
         Show("s1", s1)
         Console.WriteLine()
         Console.WriteLine("U+0063 = LATIN SMALL LETTER C")
         Console.WriteLine("U+0301 = COMBINING ACUTE ACCENT")
         Console.WriteLine("U+0327 = COMBINING CEDILLA")
         Console.WriteLine("U+00BE = VULGAR FRACTION THREE QUARTERS")

         Console.WriteLine(divider)

         Console.WriteLine("A1) Is s1 normalized to the default form (Form C)?: {0}", s1.IsNormalized())
         Console.WriteLine("A2) Is s1 normalized to Form C?:  {0}", s1.IsNormalized(NormalizationForm.FormC))
         Console.WriteLine("A3) Is s1 normalized to Form D?:  {0}", s1.IsNormalized(NormalizationForm.FormD))
         Console.WriteLine("A4) Is s1 normalized to Form KC?: {0}", s1.IsNormalized(NormalizationForm.FormKC))
         Console.WriteLine("A5) Is s1 normalized to Form KD?: {0}", s1.IsNormalized(NormalizationForm.FormKD))

         Console.WriteLine(divider)

         Console.WriteLine("Set string s2 to each normalized form of string s1.")
         Console.WriteLine()
         Console.WriteLine("U+1E09 = LATIN SMALL LETTER C WITH CEDILLA AND ACUTE")
         Console.WriteLine("U+0033 = DIGIT THREE")
         Console.WriteLine("U+2044 = FRACTION SLASH")
         Console.WriteLine("U+0034 = DIGIT FOUR")
         Console.WriteLine(divider)

         s2 = s1.Normalize()
         Console.Write("B1) Is s2 normalized to the default form (Form C)?: ")
         Console.WriteLine(s2.IsNormalized())
         Show("s2", s2)
         Console.WriteLine()

         s2 = s1.Normalize(NormalizationForm.FormC)
         Console.Write("B2) Is s2 normalized to Form C?: ")
         Console.WriteLine(s2.IsNormalized(NormalizationForm.FormC))
         Show("s2", s2)
         Console.WriteLine()

         s2 = s1.Normalize(NormalizationForm.FormD)
         Console.Write("B3) Is s2 normalized to Form D?: ")
         Console.WriteLine(s2.IsNormalized(NormalizationForm.FormD))
         Show("s2", s2)
         Console.WriteLine()

         s2 = s1.Normalize(NormalizationForm.FormKC)
         Console.Write("B4) Is s2 normalized to Form KC?: ")
         Console.WriteLine(s2.IsNormalized(NormalizationForm.FormKC))
         Show("s2", s2)
         Console.WriteLine()

         s2 = s1.Normalize(NormalizationForm.FormKD)
         Console.Write("B5) Is s2 normalized to Form KD?: ")
         Console.WriteLine(s2.IsNormalized(NormalizationForm.FormKD))
         Show("s2", s2)
         Console.WriteLine()

      Catch e As Exception
         Console.WriteLine(e.Message)
      End Try
   End Sub 'Main

   Private Shared Sub Show(title As String, s As String)
      Console.Write("Characters in string {0} = ", title)
      Dim x As Char
      For Each x In  s.ToCharArray()
         Console.Write("{0:X4} ", AscW(x))
      Next x
      Console.WriteLine()
   End Sub 'Show
End Class 'Sample
'
'This example produces the following results:
'
'Characters in string s1 = 0063 0301 0327 00BE
'
'U+0063 = LATIN SMALL LETTER C
'U+0301 = COMBINING ACUTE ACCENT
'U+0327 = COMBINING CEDILLA
'U+00BE = VULGAR FRACTION THREE QUARTERS
'
'--------------------------------------------------------------------------------
'
'A1) Is s1 normalized to the default form (Form C)?: False
'A2) Is s1 normalized to Form C?:  False
'A3) Is s1 normalized to Form D?:  False
'A4) Is s1 normalized to Form KC?: False
'A5) Is s1 normalized to Form KD?: False
'
'--------------------------------------------------------------------------------
'
'Set string s2 to each normalized form of string s1.
'
'U+1E09 = LATIN SMALL LETTER C WITH CEDILLA AND ACUTE
'U+0033 = DIGIT THREE
'U+2044 = FRACTION SLASH
'U+0034 = DIGIT FOUR
'
'--------------------------------------------------------------------------------
'
'B1) Is s2 normalized to the default form (Form C)?: True
'Characters in string s2 = 1E09 00BE
'
'B2) Is s2 normalized to Form C?: True
'Characters in string s2 = 1E09 00BE
'
'B3) Is s2 normalized to Form D?: True
'Characters in string s2 = 0063 0327 0301 00BE
'
'B4) Is s2 normalized to Form KC?: True
'Characters in string s2 = 1E09 0033 2044 0034
'
'B5) Is s2 normalized to Form KD?: True
'Characters in string s2 = 0063 0327 0301 0033 2044 0034
'

// This example demonstrates the String.Normalize method
//                       and the String.IsNormalized method

using System;
using System.Text;

class Sample 
{
    public static void Main() 
    {
// Character c; combining characters acute and cedilla; character 3/4
    string s1 = new String( new char[] {'\u0063', '\u0301', '\u0327', '\u00BE'});
    string s2 = null;
    string divider = new String('-', 80);
    divider = String.Concat(Environment.NewLine, divider, Environment.NewLine);

    try 
    {
    Show("s1", s1);
    Console.WriteLine();
    Console.WriteLine("U+0063 = LATIN SMALL LETTER C");
    Console.WriteLine("U+0301 = COMBINING ACUTE ACCENT");
    Console.WriteLine("U+0327 = COMBINING CEDILLA");
    Console.WriteLine("U+00BE = VULGAR FRACTION THREE QUARTERS");
    Console.WriteLine(divider);

    Console.WriteLine("A1) Is s1 normalized to the default form (Form C)?: {0}", 
                                 s1.IsNormalized());
    Console.WriteLine("A2) Is s1 normalized to Form C?:  {0}", 
                                 s1.IsNormalized(NormalizationForm.FormC));
    Console.WriteLine("A3) Is s1 normalized to Form D?:  {0}", 
                                 s1.IsNormalized(NormalizationForm.FormD));
    Console.WriteLine("A4) Is s1 normalized to Form KC?: {0}", 
                                 s1.IsNormalized(NormalizationForm.FormKC));
    Console.WriteLine("A5) Is s1 normalized to Form KD?: {0}", 
                                 s1.IsNormalized(NormalizationForm.FormKD));

    Console.WriteLine(divider);

    Console.WriteLine("Set string s2 to each normalized form of string s1.");
    Console.WriteLine();
    Console.WriteLine("U+1E09 = LATIN SMALL LETTER C WITH CEDILLA AND ACUTE");
    Console.WriteLine("U+0033 = DIGIT THREE");
    Console.WriteLine("U+2044 = FRACTION SLASH");
    Console.WriteLine("U+0034 = DIGIT FOUR");
    Console.WriteLine(divider);

    s2 = s1.Normalize();
    Console.Write("B1) Is s2 normalized to the default form (Form C)?: ");
    Console.WriteLine(s2.IsNormalized());
    Show("s2", s2);
    Console.WriteLine();

    s2 = s1.Normalize(NormalizationForm.FormC);
    Console.Write("B2) Is s2 normalized to Form C?: ");
    Console.WriteLine(s2.IsNormalized(NormalizationForm.FormC));
    Show("s2", s2);
    Console.WriteLine();

    s2 = s1.Normalize(NormalizationForm.FormD);
    Console.Write("B3) Is s2 normalized to Form D?: ");
    Console.WriteLine(s2.IsNormalized(NormalizationForm.FormD));
    Show("s2", s2);
    Console.WriteLine();

    s2 = s1.Normalize(NormalizationForm.FormKC);
    Console.Write("B4) Is s2 normalized to Form KC?: ");
    Console.WriteLine(s2.IsNormalized(NormalizationForm.FormKC));
    Show("s2", s2);
    Console.WriteLine();

    s2 = s1.Normalize(NormalizationForm.FormKD);
    Console.Write("B5) Is s2 normalized to Form KD?: ");
    Console.WriteLine(s2.IsNormalized(NormalizationForm.FormKD));
    Show("s2", s2);
    Console.WriteLine();
    }

    catch (Exception e) 
        {
        Console.WriteLine(e.Message);
        }
    }

    private static void Show(string title, string s)
    {
    Console.Write("Characters in string {0} = ", title);
    foreach(short x in s.ToCharArray())
        {
        Console.Write("{0:X4} ", x);
        }
    Console.WriteLine();
    }
}
/*
This example produces the following results:

Characters in string s1 = 0063 0301 0327 00BE

U+0063 = LATIN SMALL LETTER C
U+0301 = COMBINING ACUTE ACCENT
U+0327 = COMBINING CEDILLA
U+00BE = VULGAR FRACTION THREE QUARTERS

--------------------------------------------------------------------------------

A1) Is s1 normalized to the default form (Form C)?: False
A2) Is s1 normalized to Form C?:  False
A3) Is s1 normalized to Form D?:  False
A4) Is s1 normalized to Form KC?: False
A5) Is s1 normalized to Form KD?: False

--------------------------------------------------------------------------------

Set string s2 to each normalized form of string s1.

U+1E09 = LATIN SMALL LETTER C WITH CEDILLA AND ACUTE
U+0033 = DIGIT THREE
U+2044 = FRACTION SLASH
U+0034 = DIGIT FOUR

--------------------------------------------------------------------------------

B1) Is s2 normalized to the default form (Form C)?: True
Characters in string s2 = 1E09 00BE

B2) Is s2 normalized to Form C?: True
Characters in string s2 = 1E09 00BE

B3) Is s2 normalized to Form D?: True
Characters in string s2 = 0063 0327 0301 00BE

B4) Is s2 normalized to Form KC?: True
Characters in string s2 = 1E09 0033 2044 0034

B5) Is s2 normalized to Form KD?: True
Characters in string s2 = 0063 0327 0301 0033 2044 0034

*/

// This example demonstrates the String.Normalize method
//                       and the String.IsNormalized method
using namespace System;
using namespace System::Text;
void Show( String^ title, String^ s )
{
   Console::Write( "Characters in string {0} = ", title );
   System::Collections::IEnumerator^ myEnum = s->ToCharArray()->GetEnumerator();
   while ( myEnum->MoveNext() )
   {

      /*) * __try_cast < Char * > ( myEnum -> Current );*/
      int x;
      Console::Write( "{0:X4} ", x );
   }

   Console::WriteLine();
}

int main()
{

   // Character c; combining characters acute and cedilla; character 3/4
   array<Char>^temp0 = {L'c',L'\u0301',L'\u0327',L'\u00BE'};
   String^ s1 = gcnew String( temp0 );
   String^ s2 = nullptr;
   String^ divider = gcnew String( '-',80 );
   divider = String::Concat( Environment::NewLine, divider, Environment::NewLine );
   try
   {
      Show( "s1", s1 );
      Console::WriteLine();
      Console::WriteLine( "U+0063 = LATIN SMALL LETTER C" );
      Console::WriteLine( "U+0301 = COMBINING ACUTE ACCENT" );
      Console::WriteLine( "U+0327 = COMBINING CEDILLA" );
      Console::WriteLine( "U+00BE = VULGAR FRACTION THREE QUARTERS" );
      Console::WriteLine( divider );
      Console::WriteLine( "A1) Is s1 normalized to the default form (Form C)?: {0}", s1->IsNormalized() );
      Console::WriteLine( "A2) Is s1 normalized to Form C?:  {0}", s1->IsNormalized( NormalizationForm::FormC ) );
      Console::WriteLine( "A3) Is s1 normalized to Form D?:  {0}", s1->IsNormalized( NormalizationForm::FormD ) );
      Console::WriteLine( "A4) Is s1 normalized to Form KC?: {0}", s1->IsNormalized( NormalizationForm::FormKC ) );
      Console::WriteLine( "A5) Is s1 normalized to Form KD?: {0}", s1->IsNormalized( NormalizationForm::FormKD ) );
      Console::WriteLine( divider );
      Console::WriteLine( "Set string s2 to each normalized form of string s1." );
      Console::WriteLine();
      Console::WriteLine( "U+1E09 = LATIN SMALL LETTER C WITH CEDILLA AND ACUTE" );
      Console::WriteLine( "U+0033 = DIGIT THREE" );
      Console::WriteLine( "U+2044 = FRACTION SLASH" );
      Console::WriteLine( "U+0034 = DIGIT FOUR" );
      Console::WriteLine( divider );
      s2 = s1->Normalize();
      Console::Write( "B1) Is s2 normalized to the default form (Form C)?: " );
      Console::WriteLine( s2->IsNormalized() );
      Show( "s2", s2 );
      Console::WriteLine();
      s2 = s1->Normalize( NormalizationForm::FormC );
      Console::Write( "B2) Is s2 normalized to Form C?: " );
      Console::WriteLine( s2->IsNormalized( NormalizationForm::FormC ) );
      Show( "s2", s2 );
      Console::WriteLine();
      s2 = s1->Normalize( NormalizationForm::FormD );
      Console::Write( "B3) Is s2 normalized to Form D?: " );
      Console::WriteLine( s2->IsNormalized( NormalizationForm::FormD ) );
      Show( "s2", s2 );
      Console::WriteLine();
      s2 = s1->Normalize( NormalizationForm::FormKC );
      Console::Write( "B4) Is s2 normalized to Form KC?: " );
      Console::WriteLine( s2->IsNormalized( NormalizationForm::FormKC ) );
      Show( "s2", s2 );
      Console::WriteLine();
      s2 = s1->Normalize( NormalizationForm::FormKD );
      Console::Write( "B5) Is s2 normalized to Form KD?: " );
      Console::WriteLine( s2->IsNormalized( NormalizationForm::FormKD ) );
      Show( "s2", s2 );
      Console::WriteLine();
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( e->Message );
   }

}

/*
This example produces the following results:

Characters in string s1 = 0063 0301 0327 00BE

U+0063 = LATIN SMALL LETTER C
U+0301 = COMBINING ACUTE ACCENT
U+0327 = COMBINING CEDILLA
U+00BE = VULGAR FRACTION THREE QUARTERS

--------------------------------------------------------------------------------

A1) Is s1 normalized to the default form (Form C)?: False
A2) Is s1 normalized to Form C?:  False
A3) Is s1 normalized to Form D?:  False
A4) Is s1 normalized to Form KC?: False
A5) Is s1 normalized to Form KD?: False

--------------------------------------------------------------------------------

Set string s2 to each normalized form of string s1.

U+1E09 = LATIN SMALL LETTER C WITH CEDILLA AND ACUTE
U+0033 = DIGIT THREE
U+2044 = FRACTION SLASH
U+0034 = DIGIT FOUR

--------------------------------------------------------------------------------

B1) Is s2 normalized to the default form (Form C)?: True
Characters in string s2 = 1E09 00BE

B2) Is s2 normalized to Form C?: True
Characters in string s2 = 1E09 00BE

B3) Is s2 normalized to Form D?: True
Characters in string s2 = 0063 0327 0301 00BE

B4) Is s2 normalized to Form KC?: True
Characters in string s2 = 1E09 0033 2044 0034

B5) Is s2 normalized to Form KD?: True
Characters in string s2 = 0063 0327 0301 0033 2044 0034

*/

// This example demonstrates the String.Normalize method
//                       and the String.IsNormalized method
import System.*;
import System.Text.*;

class Sample
{
    public static void main(String[] args)
    {
        // Character c; combining characters acute and cedilla; character 3/4
        String s1 = new String(new char[] { '\u0063', '\u0301', '\u0327', 
            '\u00BE' });
        String s2 = null;
        String divider = new String('-', 80);
        divider = String.Concat(Environment.get_NewLine(), divider, 
            Environment.get_NewLine());

        try {
            Show("s1", s1);
            Console.WriteLine();
            Console.WriteLine("U+0063 = LATIN SMALL LETTER C");
            Console.WriteLine("U+0301 = COMBINING ACUTE ACCENT");
            Console.WriteLine("U+0327 = COMBINING CEDILLA");
            Console.WriteLine("U+00BE = VULGAR FRACTION THREE QUARTERS");
            Console.WriteLine(divider);

            Console.WriteLine("A1) Is s1 normalized to the default form " 
                + "(Form C)?: {0}", System.Convert.ToString(s1.IsNormalized()));
            Console.WriteLine("A2) Is s1 normalized to Form C?:  {0}", 
                System.Convert.ToString(s1.
                IsNormalized(NormalizationForm.FormC)));
            Console.WriteLine("A3) Is s1 normalized to Form D?:  {0}", 
                System.Convert.ToString(s1.
                IsNormalized(NormalizationForm.FormD)));
            Console.WriteLine("A4) Is s1 normalized to Form KC?: {0}", 
                System.Convert.ToString(s1.
                IsNormalized(NormalizationForm.FormKC)));
            Console.WriteLine("A5) Is s1 normalized to Form KD?: {0}", 
                System.Convert.ToString(s1.
                IsNormalized(NormalizationForm.FormKD)));

            Console.WriteLine(divider);

            Console.WriteLine("Set string s2 to each normalized form of " 
                + "string s1.");
            Console.WriteLine();
            Console.WriteLine("U+1E09 = LATIN SMALL LETTER C WITH CEDILLA " 
                + "AND ACUTE");
            Console.WriteLine("U+0033 = DIGIT THREE");
            Console.WriteLine("U+2044 = FRACTION SLASH");
            Console.WriteLine("U+0034 = DIGIT FOUR");
            Console.WriteLine(divider);

            s2 = s1.Normalize();
            Console.Write("B1) Is s2 normalized to the default form " 
                + "(Form C)?: ");
            Console.WriteLine(s2.IsNormalized());
            Show("s2", s2);
            Console.WriteLine();

            s2 = s1.Normalize(NormalizationForm.FormC);
            Console.Write("B2) Is s2 normalized to Form C?: ");
            Console.WriteLine(s2.IsNormalized(NormalizationForm.FormC));
            Show("s2", s2);
            Console.WriteLine();

            s2 = s1.Normalize(NormalizationForm.FormD);
            Console.Write("B3) Is s2 normalized to Form D?: ");
            Console.WriteLine(s2.IsNormalized(NormalizationForm.FormD));
            Show("s2", s2);
            Console.WriteLine();

            s2 = s1.Normalize(NormalizationForm.FormKC);
            Console.Write("B4) Is s2 normalized to Form KC?: ");
            Console.WriteLine(s2.IsNormalized(NormalizationForm.FormKC));
            Show("s2", s2);
            Console.WriteLine();

            s2 = s1.Normalize(NormalizationForm.FormKD);
            Console.Write("B5) Is s2 normalized to Form KD?: ");
            Console.WriteLine(s2.IsNormalized(NormalizationForm.FormKD));
            Show("s2", s2);
            Console.WriteLine();
        }
        catch (System.Exception e) {
            Console.WriteLine(e.get_Message());
        }
    } //main

    private static void Show(String title, String s)
    {
        Console.Write("Characters in string {0} = ", title);
        char myCharArray[] = s.ToCharArray();
        for (int iCtr = 0; iCtr < myCharArray.length; iCtr++) {
            char c = myCharArray[iCtr];
            Console.Write(((System.Int32)c).ToString("X4") + " ");
        }
        Console.WriteLine();
    } //Show
} //Sample
/*
This example produces the following results:

Characters in string s1 = 0063 0301 0327 00BE

U+0063 = LATIN SMALL LETTER C
U+0301 = COMBINING ACUTE ACCENT
U+0327 = COMBINING CEDILLA
U+00BE = VULGAR FRACTION THREE QUARTERS

--------------------------------------------------------------------------------

A1) Is s1 normalized to the default form (Form C)?: False
A2) Is s1 normalized to Form C?:  False
A3) Is s1 normalized to Form D?:  False
A4) Is s1 normalized to Form KC?: False
A5) Is s1 normalized to Form KD?: False

--------------------------------------------------------------------------------

Set string s2 to each normalized form of string s1.

U+1E09 = LATIN SMALL LETTER C WITH CEDILLA AND ACUTE
U+0033 = DIGIT THREE
U+2044 = FRACTION SLASH
U+0034 = DIGIT FOUR

--------------------------------------------------------------------------------

B1) Is s2 normalized to the default form (Form C)?: True
Characters in string s2 = 1E09 00BE

B2) Is s2 normalized to Form C?: True
Characters in string s2 = 1E09 00BE

B3) Is s2 normalized to Form D?: True
Characters in string s2 = 0063 0327 0301 00BE

B4) Is s2 normalized to Form KC?: True
Characters in string s2 = 1E09 0033 2044 0034

B5) Is s2 normalized to Form KD?: True
Characters in string s2 = 0063 0327 0301 0033 2044 0034

*/

参照

概念

正規化と並べ替え