while( m/ \G .*? (?= \\[FSTRE]\\ ) /gx ) {
	my $pos = pos;

	s{ \G \\F\\ }{ "|"  }egx
	or s{ \G \\S\\ }{ "^"  }egx
	or s{ \G \\T\\ }{ "&"  }egx
	or s{ \G \\R\\ }{ "~"  }egx
	or s{ \G \\E\\ }{ "\\" }egx;

	pos() = $pos + 1;
}