public void Consume()
    {
        // null substring
        {
            Substring s= new Substring();
            Substring r= new Substring("oldval");
            UT_EQ(  '\0',      s.Consume       ( )         );
            UT_EQ(  0,         s.Consume       (  0   , r) ); UT_TRUE(r.IsNull());
            UT_EQ(  0,         s.Consume       (  5   , r) ); UT_TRUE(r.IsNull());
            UT_EQ(  false,     s.Consume       ( 'a' )     );
            UT_EQ(  false,     s.Consume       ( "word" )  );
            UT_EQ(  '\0',      s.ConsumeFromEnd( )         );
            UT_EQ(  0,         s.ConsumeFromEnd(  0  )     );
            UT_EQ(  0,         s.ConsumeFromEnd(  5  )     );
            UT_EQ(  false,     s.ConsumeFromEnd( 'a' )     );
            UT_EQ(  false,     s.ConsumeFromEnd( "word" )  );
        }

        // empty substring
        {
            Substring s= new Substring("aaaaaaaaaaaa");
            Substring r= new Substring("oldval");
            s.Start= 5;
            s.End=   4;
            UT_EQ(  '\0',      s.Consume       ( )         );
            UT_EQ(  0,         s.Consume       (  0  ,r )  ); UT_TRUE( r.IsNotNull()); UT_TRUE(r.IsEmpty());
            UT_EQ(  0,         s.Consume       (  5  ,r )  ); UT_TRUE( r.IsNotNull()); UT_TRUE(r.IsEmpty());
            UT_EQ(  false,     s.Consume       ( 'a' )     );
            UT_EQ(  false,     s.Consume       ( "word" )  );
            UT_EQ(  '\0',      s.ConsumeFromEnd( )         );
            UT_EQ(  0,         s.ConsumeFromEnd(  0  )     );
            UT_EQ(  0,         s.ConsumeFromEnd(  5  )     );
            UT_EQ(  false,     s.ConsumeFromEnd( 'a' )     );
            UT_EQ(  false,     s.ConsumeFromEnd( "word" )  );
        }

        // substring of length 1
        {
            Substring s= new Substring("aaaaaaaaaaaa");
            Substring r= new Substring("oldval");

            s.Start= s.End= 5; UT_EQ(  'a',       s.Consume       ( )         ); UT_EQ( 0, s.Length() );
            s.Start= s.End= 5; UT_EQ(  1,         s.Consume       (  0  )     ); UT_EQ( 1, s.Length() );
            s.Start= s.End= 5; UT_EQ(  0,         s.Consume       (  1  , r ) ); UT_EQ( 0, s.Length() ); UT_TRUE(r.Equals("a"));
            s.Start= s.End= 5; UT_EQ(  0,         s.Consume       (  5  , r ) ); UT_EQ( 0, s.Length() ); UT_TRUE(r.Equals("a"));
            s.Start= s.End= 5; UT_EQ(  true,      s.Consume       ( 'a' )     ); UT_EQ( 0, s.Length() );
            s.Start= s.End= 5; UT_EQ(  false,     s.Consume       ( 'b' )     ); UT_EQ( 1, s.Length() );
            s.Start= s.End= 5; UT_EQ(  false,     s.Consume       ( "word" )  ); UT_EQ( 1, s.Length() );
            s.Start= s.End= 5; UT_EQ(  'a',       s.ConsumeFromEnd( )         ); UT_EQ( 0, s.Length() );
            s.Start= s.End= 5; UT_EQ(  1,         s.ConsumeFromEnd(  0  )     ); UT_EQ( 1, s.Length() );
            s.Start= s.End= 5; UT_EQ(  0,         s.ConsumeFromEnd(  1  )     ); UT_EQ( 0, s.Length() );
            s.Start= s.End= 5; UT_EQ(  0,         s.ConsumeFromEnd(  5  )     ); UT_EQ( 0, s.Length() );
            s.Start= s.End= 5; UT_EQ(  true,      s.ConsumeFromEnd( 'a' )     ); UT_EQ( 0, s.Length() );
            s.Start= s.End= 5; UT_EQ(  false,     s.ConsumeFromEnd( 'b' )     ); UT_EQ( 1, s.Length() );
            s.Start= s.End= 5; UT_EQ(  false,     s.ConsumeFromEnd( "word" )  ); UT_EQ( 1, s.Length() );
        }

        // substring of length 2
        {
            Substring s= new Substring("12ab3456");
            Substring r= new Substring("oldval");

            s.Start= 2; s.End= 3; UT_EQ(  'a',       s.Consume       ( )         ); UT_EQ( 1, s.Length() );
                                  UT_EQ(  'b',       s.Consume       ( )         ); UT_EQ( 0, s.Length() );
            s.Start= 2; s.End= 3; UT_EQ(  'b',       s.ConsumeFromEnd( )         ); UT_EQ( 1, s.Length() );
                                  UT_EQ(  'a',       s.ConsumeFromEnd( )         ); UT_EQ( 0, s.Length() );

            s.Start= 2; s.End= 3; UT_EQ(  2,         s.Consume       (  0 , r )  ); UT_EQ( 2, s.Length() ); UT_TRUE(r.IsNotNull()); UT_TRUE(r.IsEmpty());
            s.Start= 2; s.End= 3; UT_EQ(  1,         s.Consume       (  1 , r )  ); UT_EQ( 1, s.Length() ); UT_TRUE(r.Equals("a"));
            s.Start= 2; s.End= 3; UT_EQ(  0,         s.Consume       (  2 , r )  ); UT_EQ( 0, s.Length() ); UT_TRUE(r.Equals("ab"));
            s.Start= 2; s.End= 3; UT_EQ(  0,         s.Consume       (  3 , r )  ); UT_EQ( 0, s.Length() ); UT_TRUE(r.Equals("ab"));
            s.Start= 2; s.End= 3; UT_EQ(  2,         s.ConsumeFromEnd(  0 , r )  ); UT_EQ( 2, s.Length() ); UT_TRUE(r.IsNotNull()); UT_TRUE(r.IsEmpty());
            s.Start= 2; s.End= 3; UT_EQ(  1,         s.ConsumeFromEnd(  1 , r )  ); UT_EQ( 1, s.Length() ); UT_TRUE(r.Equals("b"));
            s.Start= 2; s.End= 3; UT_EQ(  0,         s.ConsumeFromEnd(  2 , r )  ); UT_EQ( 0, s.Length() ); UT_TRUE(r.Equals("ab"));
            s.Start= 2; s.End= 3; UT_EQ(  0,         s.ConsumeFromEnd(  3 , r )  ); UT_EQ( 0, s.Length() ); UT_TRUE(r.Equals("ab"));

            s.Start= 2; s.End= 3; UT_EQ(  false,     s.Consume       ( 'b' )     ); UT_EQ( 2, s.Length() );
                                  UT_EQ(  true,      s.Consume       ( 'a' )     ); UT_EQ( 1, s.Length() );
                                  UT_EQ(  true,      s.Consume       ( 'b' )     ); UT_EQ( 0, s.Length() );
                                  UT_EQ(  false,     s.Consume       ( 'a' )     ); UT_EQ( 0, s.Length() );
                                  UT_EQ(  false,     s.Consume       ( 'b' )     ); UT_EQ( 0, s.Length() );
            s.Start= 2; s.End= 3; UT_EQ(  false,     s.ConsumeFromEnd( 'a' )     ); UT_EQ( 2, s.Length() );
                                  UT_EQ(  true,      s.ConsumeFromEnd( 'b' )     ); UT_EQ( 1, s.Length() );
                                  UT_EQ(  true,      s.ConsumeFromEnd( 'a' )     ); UT_EQ( 0, s.Length() );
                                  UT_EQ(  false,     s.ConsumeFromEnd( 'b' )     ); UT_EQ( 0, s.Length() );
                                  UT_EQ(  false,     s.ConsumeFromEnd( 'a' )     ); UT_EQ( 0, s.Length() );

            s.Start= 2; s.End= 3; UT_EQ(  false,     s.Consume       ( "word" )  ); UT_EQ( 2, s.Length() );
            s.Start= 2; s.End= 3; UT_EQ(  false,     s.Consume       ( "AB"   )  ); UT_EQ( 2, s.Length() );
            s.Start= 2; s.End= 3; UT_EQ(  true,      s.Consume       ( "ab"   )  ); UT_EQ( 0, s.Length() );
            s.Start= 2; s.End= 3; UT_EQ(  false,     s.ConsumeFromEnd( "word" )  ); UT_EQ( 2, s.Length() );
            s.Start= 2; s.End= 3; UT_EQ(  false,     s.ConsumeFromEnd( "AB"   )  ); UT_EQ( 2, s.Length() );
            s.Start= 2; s.End= 3; UT_EQ(  true,      s.ConsumeFromEnd( "ab"   )  ); UT_EQ( 0, s.Length() );
        }

        // 3 words
        {
            Substring s= new Substring("word1 word2 word3");

            UT_EQ(  'w',       s.Consume       ( )         );
            UT_EQ(  'o',       s.Consume       ( )         );
            UT_EQ(  'r',       s.Consume       ( )         );
            UT_EQ(  'd',       s.Consume       ( )         );
            UT_EQ(  '1',       s.Consume       ( )         );

            UT_EQ(  false    , s.Consume       ('w'                        )   );
            UT_EQ(  true     , s.Consume       ('w'     , Case.Sensitive, Whitespaces.Trim )   );
            UT_EQ(  true     , s.Consume       ('o'     , Case.Sensitive, Whitespaces.Trim )   );
            UT_EQ(  false    , s.Consume       ('o'     , Case.Sensitive, Whitespaces.Trim )   );
            UT_EQ(  true     , s.Consume       ('r'     , Case.Sensitive, Whitespaces.Trim )   );
            UT_EQ(  false    , s.Consume       ("D2"    , Case.Sensitive, Whitespaces.Trim )   );
            UT_EQ(  false    , s.Consume       ("D2"                       )   );
            UT_EQ(  true     , s.Consume       ("d2"                       )   );

            UT_EQ(  2        , s.Consume       ( 4 )   );
            UT_EQ(  "d3"     , s.ToString() );

                      s= new Substring("word1 word2 word3");

            UT_EQ(  '3',       s.ConsumeFromEnd( )         );
            UT_EQ(  'd',       s.ConsumeFromEnd( )         );
            UT_EQ(  'r',       s.ConsumeFromEnd( )         );
            UT_EQ(  'o',       s.ConsumeFromEnd( )         );
            UT_EQ(  'w',       s.ConsumeFromEnd( )         );

            UT_EQ(  false    , s.ConsumeFromEnd('2'                        )   );
            UT_EQ(  true     , s.ConsumeFromEnd('2'     , Case.Sensitive, Whitespaces.Trim )   );
            UT_EQ(  true     , s.ConsumeFromEnd('d'     , Case.Sensitive, Whitespaces.Trim )   );
            UT_EQ(  false    , s.ConsumeFromEnd('d'     , Case.Sensitive, Whitespaces.Trim )   );
            UT_EQ(  true     , s.ConsumeFromEnd('r'     , Case.Sensitive, Whitespaces.Trim )   );
            UT_EQ(  false    , s.ConsumeFromEnd("WO"    , Case.Sensitive, Whitespaces.Trim )   );
            UT_EQ(  false    , s.ConsumeFromEnd("WO"                       )   );
            UT_EQ(  true     , s.ConsumeFromEnd("wo"                       )   );

            UT_EQ(  2        , s.ConsumeFromEnd( 4 )   );
            UT_EQ(  "wo"     , s.ToString() );
        }

        // consume AString, Substring
        {
            Substring s= new Substring("word1 word2 word3 word4");
            Substring sConsume= new Substring( "1234word12", 4, 4 );
            AString   aConsume= new AString  (     "word"         );

            UT_EQ(  true,      s.Consume       ( sConsume )  );
            UT_EQ(  false,     s.Consume       ( sConsume )  );
            UT_EQ(  '1',       s.Consume       ( )           );
            UT_EQ(  false,     s.Consume       ( sConsume )  );
            UT_EQ(  true,      s.Consume       ( sConsume, Case.Sensitive, Whitespaces.Trim ) );
            UT_EQ(  '2',       s.Consume       ( )           );
            UT_EQ(  ' ',       s.Consume       ( )           );

            UT_EQ(  true,      s.Consume       ( aConsume )  );
            UT_EQ(  false,     s.Consume       ( aConsume )  );
            UT_EQ(  '3',       s.Consume       ( )           );
            UT_EQ(  false,     s.Consume       ( aConsume )  );
            UT_EQ(  true,      s.Consume       ( aConsume, Case.Sensitive, Whitespaces.Trim ) );

                      s.Set("1word  2word 3word  4word");

            UT_EQ(  true,      s.ConsumeFromEnd( sConsume )  );
            UT_EQ(  false,     s.ConsumeFromEnd( sConsume )  );
            UT_EQ(  '4',       s.ConsumeFromEnd( )           );
            UT_EQ(  false,     s.ConsumeFromEnd( sConsume )  );
            UT_EQ(  true,      s.ConsumeFromEnd( sConsume, Case.Sensitive, Whitespaces.Trim ) );
            UT_EQ(  '3',       s.ConsumeFromEnd( )           );
            UT_EQ(  ' ',       s.ConsumeFromEnd( )           );

            UT_EQ(  true,      s.ConsumeFromEnd( aConsume )  );
            UT_EQ(  false,     s.ConsumeFromEnd( aConsume )  );
            UT_EQ(  '2',       s.ConsumeFromEnd( )           );
            UT_EQ(  false,     s.ConsumeFromEnd( aConsume )  );
            UT_EQ(  true,      s.ConsumeFromEnd( aConsume, Case.Sensitive, Whitespaces.Trim ) );
        }
    }