[Pyparsing] Get Better Error Messages - Prevent Backtracking

[Ken K. <ksk...@gm...>]

Hi.. I'm a new pyparsing user, and I just wanted to comment on Eike
Welk's recent proposal [1] to improve error messages by stopping
backtracking at defined points using a "ErrStop" ParserElement.

It's awesome.  Totally flipping awesome.  I'd beat my head against the
wall for a couple of hours before I stumbled on it & was instantly
relieved.

I've posted a diff of the simpleSQL.py example to the pastebin [2]
that shows a use of ErrStop on a statement that was previously happily
accepted ("select * from table1 where a b" -- note the missing
operator).  The diff assumes that ErrStop has been added to pyparsing.

Thanks Eike for the solution, and to Paul for the excellent package!
-ken

PS: Sorry for creating a new thread.. I don't know how to continue the
old one when I wasn't a list member until just now.

PSS: Since the docs & examples aren't in the svn repos, the diff is
against what was in the 1.4.11 tarball.

[1]
http://sourceforge.net/mailarchive/message.php?msg_name=200804140116.37166.eike.welk%40gmx.net

[2]
http://pastebin.com/f25124b32