// parse complex numbers (functional but not completely safe, unfortunately
// std::string does not understand regexpese):
// ss should represent a simple sum like 2+5*I
- std::string ss(s);
- // make it safe by adding explicit sign
+ std::string ss = s;
+ std::string::size_type delim;
+
+ // make this implementation safe by adding explicit sign
if (ss.at(0) != '+' && ss.at(0) != '-' && ss.at(0) != '#')
ss = '+' + ss;
- std::string::size_type delim;
+
+ // We use 'E' as exponent marker in the output, but some people insist on
+ // writing 'e' at input, so let's substitute them right at the beginning:
+ while ((delim = ss.find('e'))!=std::string::npos)
+ ss = ss.replace(delim,1,'E');
+
+ // main parser loop:
do {
// chop ss into terms from left to right
std::string term;
bool imaginary = false;
delim = ss.find_first_of(std::string("+-"),1);
// Do we have an exponent marker like "31.415E-1"? If so, hop on!
- if ((delim != std::string::npos) && (ss.at(delim-1) == 'E'))
+ if (delim!=std::string::npos && ss.at(delim-1)=='E')
delim = ss.find_first_of(std::string("+-"),delim+1);
term = ss.substr(0,delim);
- if (delim != std::string::npos)
+ if (delim!=std::string::npos)
ss = ss.substr(delim);
// is the term imaginary?
- if (term.find("I") != std::string::npos) {
+ if (term.find('I')!=std::string::npos) {
// erase 'I':
- term = term.replace(term.find("I"),1,"");
+ term = term.replace(term.find('I'),1,"");
// erase '*':
- if (term.find("*") != std::string::npos)
- term = term.replace(term.find("*"),1,"");
+ if (term.find('*')!=std::string::npos)
+ term = term.replace(term.find('*'),1,"");
// correct for trivial +/-I without explicit factor on I:
- if (term.size() == 1)
- term += "1";
+ if (term.size()==1)
+ term += '1';
imaginary = true;
}
- if (term.find(".") != std::string::npos) {
+ if (term.find('.')!=std::string::npos || term.find('E')!=std::string::npos) {
// CLN's short type cl_SF is not very useful within the GiNaC
// framework where we are mainly interested in the arbitrary
// precision type cl_LF. Hence we go straight to the construction
// 31.4E-1 --> 31.4e-1_<Digits>
// and s on.
// No exponent marker? Let's add a trivial one.
- if (term.find("E") == std::string::npos)
+ if (term.find('E')==std::string::npos)
term += "E0";
// E to lower case
- term = term.replace(term.find("E"),1,"e");
+ term = term.replace(term.find('E'),1,'e');
// append _<Digits> to term
term += "_" + ToString((unsigned)Digits);
// construct float using cln::cl_F(const char *) ctor.
else
ctorval = ctorval + cln::cl_F(term.c_str());
} else {
- // not a floating point number...
+ // this is not a floating point number...
if (imaginary)
ctorval = ctorval + cln::complex(cln::cl_I(0),cln::cl_R(term.c_str()));
else
ctorval = ctorval + cln::cl_R(term.c_str());
}
- } while(delim != std::string::npos);
+ } while (delim != std::string::npos);
value = ctorval;
setflag(status_flags::evaluated | status_flags::expanded);
}