On Thu, Jan 15, 2004 at 11:17:21PM -0600, Jason E. Sibre wrote:
> If I have a syntax error in a PTL file, I get an [almost] useless exception.
> For example, I modified a good PTL file (pages.ptl) by removing a quote (")
> from line 38, and fired up python and did:
>
> import quixote as q
> q.enable_ptl()
> import pages
>
> ... and I get the following traceback:
> Traceback (most recent call last):

>   File "/usr/local/lib/python2.3/site-packages/quixote/ptl_compile.py", line
> 229, in parse
>     raise SyntaxError(str(value), (filename, lineno, offset, text))
>   File "/home/jsibre/programs/python/mp3/mp3player/web/pages.ptl", line 4
>     import time
>                ^
> SyntaxError: invalid syntax (pages.ptl, line 4)
>
> Line 4?  (It's the first non-comment line in the file.)

I can't reproduce this.  However, I believe you've run into a real
problem.  The history of this part of Quixote is pretty long.  The
short story is that the 'parser' module in Python <= 2.2 can raise
SyntaxError or ParserError.  ParserError is basically useless since
it does not include a good description of the error and is missing
the lineno.

In Python >= 2.3, the 'parser' module does not raise ParserError
when it means SyntaxError (I'm not 100% sure about this but it seems
to be true).  I don't know why things are going wrong with 2.3, but
here's my proposed fix:

if sys.hexversion >= 0x20300b1:
    def parse(buf, filename=''):
        buf = translate_tokens(buf, filename)
        return TemplateTransformer().parsesuite(buf)

else:
    # The parser module in Python <= 2.2 can raise ParserError.  Since
    # the ParserError exception is basically useless, we use compile()
    # to generate a better exception.
    def parse(buf, filename=''):
        buf = translate_tokens(buf, filename)
        try:
            return TemplateTransformer().parsesuite(buf)
        except (parser.ParserError, SyntaxError):
            import __builtin__
            try:
                __builtin__.compile(buf, filename, 'exec')
            except SyntaxError, exc:
                # Another hack to fix the filename attribute (otherwise
                # it is often "", even though we specify it).
                raise SyntaxError(str(exc), (filename, exc.lineno, exc.offset,
                                             exc.text))


Everyting in the 'else' clause is for backwards compatibility only.  It
can eventually go away.

  Neil