** Using WeBWorK **

• I load a macro file that subclasses the division, making a weird new meaning for '/'. The code is short:
  
  
  
  
  package bizarro::BOP::divide;
  our @ISA = ('Parser::BOP::divide');
  
  #
  # Return a/(b^3(2+sin(b)) when bizarroDiv is set
  #
  sub _eval {
  my $self = shift;
  my $context = $self->context;
  my ($a,$b) = @_;
  if ($context->flag("bizarroDiv")) {
  return $a/(($b)**3*(2+CORE::sin($b)));}
  else {
  return $a / $b;
  }
  }
  
  sub call {(shift)->_eval(@_)}
  
  
  

• Then in the problem, immediately following a context declaration, I have more code to make the context use the bizarro division during answer checking:
  
  Context()->operators->set(
  '/' => {class => 'bizarro::BOP::divide', isCommand => 1},
  ' /' => {class => 'bizarro::BOP::divide', isCommand => 1},
  '/ ' => {class => 'bizarro::BOP::divide', isCommand => 1},
  '//' => {class => 'bizarro::BOP::divide', isCommand => 1},
  );
  
  Context()->{cmpDefaults}{Formula}{checker} = sub {
  my ($correct,$student,$ans) = @_;
  return 0 if $ans->{isPreview} || $correct != $student;
  $student = $ans->{student_formula};
  $correct = $correct->{original_formula} if defined $correct->{original_formula};
  Context()->flags->set(bizarroDiv=> 1);
  delete $correct->{test_values}, $student->{test_values};
  my $OK = ($correct == $student); # check if equal when / is replace by bizarro /
  Context()->flags->set(bizarroDiv=> 0);
  Value::Error("Your answer is not simplified") unless $OK;
  return $OK;
  };
  

Now when say, the expected answer is "x/3", and a student answers with "2x/6", they are asked to simplify more.

I am having trouble packaging this - probably I just don't know the right perl. Is there a way for me to put all this code into the same .pl file, and then be able to activate the second part with a single command? I would be able to do something like:

loadMacros(parserBizarroDivision.pl);
...

Context("LimitedPolynomial");
ActivateBizarroDivision(); #replacing my second block of code above

$ans = Formula("x/3");
...
ANS($ans->cmp());

Note that I want to be able to use this alongside several contexts, so I do not want to make a context macro file to implement this. And I can't simply throw the code in to my existing .pl file, because the context modification parts need to happen after I have declared a context.