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  $pos = -1;
  while (($pos = CORE::index($string, $lookfor, $pos)) > -1) {
      print "Found at $pos\n";
      $pos++;
  }

=item * Rindex by Byte String

  $rindex = CORE::rindex($string,$substring,$offset);
  $rindex = CORE::rindex($string,$substring);

  This function works just like CORE::index except that it returns the position of
  the last occurrence of $substring in $string (a reverse CORE::index). The function
  returns -1 if not $substring is found. $offset, if specified, is the rightmost
  position that may be returned. To work your way through a string backward, say:

  $pos = CORE::length($string);
  while (($pos = CORE::rindex($string, $lookfor, $pos)) >= 0) {
      print "Found at $pos\n";
      $pos--;
  }

=back

=head1 Yada Yada Operator (Big5 software provides)

  The yada yada operator (noted ...) is a placeholder for code. Perl parses it
  without error, but when you try to execute a yada yada, it throws an exception
  with the text Unimplemented:

  sub unimplemented { ... }
  eval { unimplemented() };
  if ( $@ eq 'Unimplemented' ) {
      print "I found the yada yada!\n";
  }

  You can only use the yada yada to stand in for a complete statement. These
  examples of the yada yada work:

  { ... }
  sub foo { ... }
  ...;
  eval { ... };
  sub foo {
      my( $self ) = shift;
      ...;
  }
  do { my $n; ...; print 'Hurrah!' };

  The yada yada cannot stand in for an expression that is part of a larger statement
  since the ... is also the three-dot version of the range operator
  (see "Range Operators"). These examples of the yada yada are still syntax errors:

  print ...;
  open my($fh), '>', '/dev/passwd' or ...;
  if ( $condition && ... ) { print "Hello\n" };

  There are some cases where Perl can't immediately tell the difference between an
  expression and a statement. For instance, the syntax for a block and an anonymous
  hash reference constructor look the same unless there's something in the braces that
  give Perl a hint. The yada yada is a syntax error if Perl doesn't guess that the
  { ... } is a block. In that case, it doesn't think the ... is the yada yada because
  it's expecting an expression instead of a statement:

  my @transformed = map { ... } @input;  # syntax error

  You can use a ; inside your block to denote that the { ... } is a block and not a
  hash reference constructor. Now the yada yada works:

  my @transformed = map {; ... } @input; # ; disambiguates
  my @transformed = map { ...; } @input; # ; disambiguates

=head1 Un-Escaping bytes::* Subroutines (Big5 software provides)

Big5 software removes 'bytes::' at head of subroutine name.

  ---------------------------------------
  Before           After     Works as
  ---------------------------------------
  bytes::chr       chr       Byte
  bytes::index     index     Byte
  bytes::length    length    Byte
  bytes::ord       ord       Byte
  bytes::rindex    rindex    Byte
  bytes::substr    substr    Byte
  ---------------------------------------

=head1 Ignore Pragmas and Modules

  -----------------------------------------------------------
  Before                    After
  -----------------------------------------------------------
  use strict;               use strict; no strict qw(refs);
  use 5.12.0;               use 5.12.0; no strict qw(refs);
  require utf8;             # require utf8;
  require bytes;            # require bytes;
  require charnames;        # require charnames;
  require I18N::Japanese;   # require I18N::Japanese;
  require I18N::Collate;    # require I18N::Collate;
  require I18N::JExt;       # require I18N::JExt;
  require File::DosGlob;    # require File::DosGlob;
  require Wild;             # require Wild;
  require Wildcard;         # require Wildcard;
  require Japanese;         # require Japanese;
  use utf8;                 # use utf8;
  use bytes;                # use bytes;
  use charnames;            # use charnames;
  use I18N::Japanese;       # use I18N::Japanese;
  use I18N::Collate;        # use I18N::Collate;
  use I18N::JExt;           # use I18N::JExt;
  use File::DosGlob;        # use File::DosGlob;
  use Wild;                 # use Wild;
  use Wildcard;             # use Wildcard;
  use Japanese;             # use Japanese;
  no utf8;                  # no utf8;
  no bytes;                 # no bytes;
  no charnames;             # no charnames;
  no I18N::Japanese;        # no I18N::Japanese;
  no I18N::Collate;         # no I18N::Collate;
  no I18N::JExt;            # no I18N::JExt;
  no File::DosGlob;         # no File::DosGlob;