Re: [Pyparsing] Operator Precedence and Associativity.

[Ralph C. <ra...@in...>]

Hi Paul,

> This discussion from c.l.py
> (http://www.velocityreviews.com/forums/t335296-basic-tokenizer.html -
> about 2 years ago) might also shed some light on this topic,
> especially the comments (and posted code) from Andrea Griffini.  He
> pointed out the '^' left-associativity bug in fourFn.py which I was
> able to fix in a subsequent release. 

Thanks, I had already found that, and you're right, it helped concoct
the right pyparsing grammar, as in fourFn.py.  The issue is I don't want
[1, '+', 2, '+', 3] returned, but [[1, '+', 2], '+', 3] which doesn't
seem possible without post-parsing manipulation.

That is, the `classic' parse tree of an infix algebraic expression isn't
achievable.

> I like the graphical rending of the parse tree. :)

Yes, it just occurred to me when I was sitting there with the text all
on one line.  Not hard to do, either, with vim's Ctrl-Y in insert mode.

Cheers,


Ralph.