On 4/7/2011 10:02 AM, Steven Watanabe wrote:
AMDG
On 04/06/2011 03:12 PM, Littlefield, Tyler wrote:
Sorry for all the questions; I am kind of easing into boost and finding cool things i can do with it, as well as uses for a couple of projects. Eventually I would like to write a small scripting language using boost::spirit, just to do it and get the practice using it. As a starting point, I wrote a quick calculator (that just does small single operations like x+x, x*x, etc). Now i have two questions. 1) My rule seems to be off. the first number comes through clearly, but no matter what I put in, I always get the first number and then a 42. 2) How would I go about extending this to implement order of operations, parenthases, and longer operations (like 3+3*3)? I'm going to try to implement a small function table so I can do tan(3), so I assume I will need nultiple rules, how might that be accomplished? Any comments and suggestions would be welcome. I have pasted the code below. I was working from a tutorial, so early appologies if it feels messy; I plan to clean up the namespace aliases and the using keywords.
Spirit used to have a calculator example, but I can't seem to find it in the new docs.
Check out the "compiler_tutorial" directory. It's a progression from the simplest calculator to a mini-c compiler and a virtual machine. I intend to write a series of articles using these examples. Regards, -- Joel de Guzman http://www.boostpro.com http://boost-spirit.com