On Mon, 25 Oct 2004, EECS student wrote:

> Prof. Wolff,
> 
> We have a few questions regarding the code that was provided for
> assignment 3.  First of all, the default case throws a null pointer
> exception.  We added a check for null in getParam() to ensure that
> mainargv was initialized and then it was able to function.  Secondly,
> the second test case confuses us.  The argument you suggested we pass
> to the command line is 'html=hello, <b>EECS<bb>382'.  This doesn't
> work unless the argument is in double quotes.  Once we changed this
> the proper text was output.

For a unix/linux it will work. For msdos, you are probably correct.
The quotes allow arguments to have blanks.

The <bb> is a "made-up thing" and should be replaced properly with </b>.
I left that code for you to write. But <bb> should still work as </b>.

  However, in this case EECS is the only
> word in the applet that is displayed in bold.

Correct, since, <bb> behaves as </b>

> Because the <b> tag is not properly closed,

It is, I just called <bb>

> shouldn't the text follwing (in this case the
> 382) also be displayed in bold?

No, since I treat <bb> as </b>. I want you to modify the state
machine to handle </tags>

> Also, in the paint() method there is
> a check for the "bb" invalid tag.

You are suppose to remove the <bb> tag. Invalid tags are to be
ignored.

It checks if a "Font" object is on the stack which is what 
Is it necessary to check for specific invalid tags?

Because when you do subscripting <SUB>...</SUB> you will push
an integer object on the stack. Hence the stack will contain
mixed object types. So, </SUB> should see an integer object and
not a Font object: <B>A<SUB>IJ</SUB>=3;<B> is good html and
a bad example is: <B>AIJ</SUB>=3;<B>

or can we just throw away all tags that are
> not recognized by our parser? 

Yes-No, ignore all tags and text in the head 
but ignore only tags in the body.

--frank.

 We would appreciate some clarification
> on these issues.  Thanks so much!
>