Alan M. Carroll wrote:
At 05:49 PM 6/21/2009, you wrote:
Christopher Jefferson wrote:
Looking at the documentation, Boost::Spirit seems like a very big hammer to crack this quite small nut, and it is unclear to me how well it would fit into an existing recursive decent parser. Has anyone ever used it as such? Is there a simple alternative? Spirit is well tuned for small parsing tasks like this. It is a modular RD parser. What you need is what you pay for. The code is as tight as it can be.
I don't think this solves his problem.
What is the problem? Speed, right? Then I don't see why it does not solve the problem.
Note that he got a 10X speed up by changing to a buffer with his existing parser, so the _parsing_ code isn't the bottle neck. It's better I/O that's needed. I suspect
And Spirit uses a better I/O through generic Forward Iterators.
it's the locking done by streams on each operation, so he's basically doing a lock on every character. I think he'd be better off using the forward iterator idea and then either writing a small wrapper class on streams to block read or use the lower level read buffer interface.
I think you are under-estimating the complexity of writing a humble number parser from a Forward Iterator. It's not as simple as it looks and gets pretty hairy when you get past the toy examples. Regards, -- Joel de Guzman http://www.boostpro.com http://spirit.sf.net