If you were aiming for overriding the default printing behavior at the repl/in test results, the method is `_torepr`.  The only odd man out is `tostring`, which doesn't have the underscore.

Also, usually I try to have `_torepr` print to something that can be read back in to an "==" value.  For example, for arrays Pyret prints:

    array([1,2,3])

which works as a constructor for the array.  Now, it might not always work because the constructor might be inside another object, but the structure you're printing only sort of resembles a Pyret expression.