This is my first post on this forum, hopefully It'll be according to the posting rules.
For the small (school) project I'm currently working on I am trying to implement an infix-to-postfix translator (Reverse Polish Notation: RPN). T
he reason behind this is that I want to be able to execute expressions on a CUDA-capable GPU (CUDA) which doesn't have support for recursion (so no expression trees etc).
So for example I have an expression like: 3 + 4 * 2 / (1 - 5) ^ 2 ^ 3 and I want to translate that to the postfix notation like: 3 4 2 * 1 5 - 2 3 ^ ^ / +.
The expression will come from a different program and these will include variable names as well, so something like 3 + (2 / x) ^ y ^ z but that is not what I am having problems with now (or, not yet..).
Currently my program can deal with expressions like the ones above, but only because each element in the string literal is a token, so I can walk through the string doing something on each element. However, this does not work when values are floats or negative values. The expression 3.14 / -.2 + (2.5 * x) needs to be split into tokens in a whole different way.
I am not experienced enough to find a method that can split such an expression in the way I would like, namely: '3.14', '/', '-.2', '+', '(', '2.5', '*', 'x', ')'.
This data would then be stored in a struct holding both values and operators. I thought about using a simple Perl regex, but since I plan on distributing the program (later on) I don't feel much about asking people to also install Perl just to run it.
I tried using strtok() for this, but since I can't just split on, say, spaces since I can't be sure that all elements are separated by spaces, especially when there are brackets in the expression. My question is really more about a direction I should go instead of complete working code examples, but if someone knows about an existing infix->postfix translator in plain C (couldn't find one!) that would be very great indeed!
Thanks for your time,