On 21 Aug 2002 at 10:34, Fredrik Lundh wrote:
eh? why did my mailer send that mail? what I was trying to say is that I'm mildly curious why people tend to treat mxTextTools like some kind of silver bullet, without actually comparing it to a well- written regular expression.
I've heard from people who've spent days rewriting their application, only to find that the resulting program was slower.
(as Guido noted, for problems like this, the overhead isn't so much in the engine itself, as in the effort needed to create Python data structures...)
mxTextTools lets (encourages?) you to break all the rules about lex -> parse. If you can (& want to) put a good deal of the "parse" stuff into the scanning rules, you can get a speed advantage. You're also not constrained by the rules of BNF, if you choose to see that as an advantage :-). My one successful use of mxTextTools came after using SPARK to figure out what I actually needed in my AST, and realizing that the ambiguities in the grammar didn't matter in practice, so I could produce an almost-AST directly. -- Gordon http://www.mcmillan-inc.com/