Initial check in of big integer library, v2010.04.30
[pdfium.git] / third_party / bigint / BigIntegerUtils.cc
1 #include "BigIntegerUtils.hh"
2 #include "BigUnsignedInABase.hh"
3
4 std::string bigUnsignedToString(const BigUnsigned &x) {
5         return std::string(BigUnsignedInABase(x, 10));
6 }
7
8 std::string bigIntegerToString(const BigInteger &x) {
9         return (x.getSign() == BigInteger::negative)
10                 ? (std::string("-") + bigUnsignedToString(x.getMagnitude()))
11                 : (bigUnsignedToString(x.getMagnitude()));
12 }
13
14 BigUnsigned stringToBigUnsigned(const std::string &s) {
15         return BigUnsigned(BigUnsignedInABase(s, 10));
16 }
17
18 BigInteger stringToBigInteger(const std::string &s) {
19         // Recognize a sign followed by a BigUnsigned.
20         return (s[0] == '-') ? BigInteger(stringToBigUnsigned(s.substr(1, s.length() - 1)), BigInteger::negative)
21                 : (s[0] == '+') ? BigInteger(stringToBigUnsigned(s.substr(1, s.length() - 1)))
22                 : BigInteger(stringToBigUnsigned(s));
23 }
24
25 std::ostream &operator <<(std::ostream &os, const BigUnsigned &x) {
26         BigUnsignedInABase::Base base;
27         long osFlags = os.flags();
28         if (osFlags & os.dec)
29                 base = 10;
30         else if (osFlags & os.hex) {
31                 base = 16;
32                 if (osFlags & os.showbase)
33                         os << "0x";
34         } else if (osFlags & os.oct) {
35                 base = 8;
36                 if (osFlags & os.showbase)
37                         os << '0';
38         } else
39                 throw "std::ostream << BigUnsigned: Could not determine the desired base from output-stream flags";
40         std::string s = std::string(BigUnsignedInABase(x, base));
41         os << s;
42         return os;
43 }
44
45 std::ostream &operator <<(std::ostream &os, const BigInteger &x) {
46         if (x.getSign() == BigInteger::negative)
47                 os << '-';
48         os << x.getMagnitude();
49         return os;
50 }