Writing a calculator in C# using SableCC

Writing a calculator is a simple task - just add nine buttons labeled 1-9 and add a plus and minus button and we're almost good to go. In this entry I'm going to write a calculator called SimpleCalc that does not have a GUI, instead it'll take in an arbitrary expression and calculate the results of it. The input I'll use as my immediate goal is: 25-37+2*(1.22+cos(5))*sin(5)*2+5%2*3*sqrt(5+2)