NAME

contextArbitraryString.pl - Implements a context in which the student's answer is treated as a literal string, and not parsed further.

DESCRIPTION

Implements a context in which the student's answer is treated as a literal string, and not parsed further. The real answer checking should be performed in a custom checker passed to the answer string's cmp() method. E.g.,

loadMacros("contextArbitraryString.pl");
Context("ArbitraryString");

ANS(Compute("The string I want")->cmp(checker => sub {
    my ($correct,$student,$ans) = @_;
    $correct = $correct->value; # get perl string from String object
    $student = $student->value; # ditto

    # do your checking here, and return true if correct
    # or false if incorrect.  For example
    #   return $correct eq $student;

    return $score;
}));

The default checker is essentially that given above, so if you want the student answer to match the correct one exactly (spacing and case are significant), then you don't have to use a custom checker. But if you want, for example, to collapse multiple white-space, or trim leading and trailing blanks, or treat upper- and lower-case letters as quivalent, then you will need to provide your own checker that does that.

This context handles multi-line answers properly. If your answers are particularly long, the results listed in the results table when a student submits the answer may be too long, and you might want to reduce the space taken up. Since the Entered and Preview columns will contain essentially the same data, you can turn off the Preview column by using

ANS($ans->cmp(noLaTeXresults=>1));

or by setting the flag globally

Context()->flags->set(noLaTeXresults => 1);

This will put a message in the Preview column saying to look at the Entered column, and will make the correct answer be shown in HTML rather than TeX.

ANS(str_cmp("increasing"));

ANS(unordered_str_cmp("A C E"));

String answer evaluators compare a student string to the correct string.