Class CCode

fem/code_generation.cpp:238–308

This class behaves like a numeric type, but 'records' all computations in expression strings

        // This class behaves like a numeric type, but 'records' all computations in expression strings
        struct CCode {
            static std::vector<string> expressions;
            static int find( std::vector<string> &v, string val ){
                int i = 0;
                for(auto &s : v) {
                    if(s==val)
                        return i;
                    i++;
                }
                return -1;
            }

            static string strip(string s) {
                int n = s.size();
                if(n<=1) return s;
                if(s[0] == '(' && s[n-1] == ')') return strip(s.substr(1,n-2));
                return s;
            }
            mutable string s;

            static CCode Par(const CCode &c) {
                return c.s;
            }

            void Check() {
                static string int_num = "var[0-9]*";
                static regex pattern(int_num);
                if(s=="") return;
                int index = find( expressions, strip(s));
                if(index>=0) {
                    s = "var"+ToString(index);
                }
                else {
                    if(!regex_match(strip(s), pattern)) {
                        expressions.push_back(strip(s));
                        s = "var"+ToString(expressions.size()-1);
                    }
                }
            }

            CCode() : s("") { } 
          
            CCode(const CCode &c) :
              s(c.s)
            {
                Check();
            }

            CCode(string as) : s(as) {
                Check();
            }

            CCode(double val) {
                std::stringstream str;
                str << fixed << setprecision( 15 ) << val;
                s = str.str();
                Check();
            }