Added stringutil module

src/util/stringutil.cpp

@@ -0,0 +1,69 @@
+#include "stringutil.h"
+
+#include <vector>
+#include <locale>
+#include <sstream>
+
+using std::vector;
+using std::string;
+using std::stringstream;
+using std::wstring;
+using std::wstringstream;
+
+wstring lfill(wstring s, int length, wchar_t c) {
+    if (s.length() >= length) {
+        return s;
+    }
+    wstringstream ss;
+    for (int i = 0; i < length-s.length(); i++) {
+        ss << c;
+    }
+    ss << s;
+    return ss.str();
+}
+
+wstring rfill(wstring s, int length, wchar_t c) {
+    if (s.length() >= length) {
+        return s;
+    }
+    wstringstream ss;
+    ss << s;
+    for (int i = 0; i < length-s.length(); i++) {
+        ss << c;
+    }
+    return ss.str();
+}
+
+uint encode_utf8(uint c, ubyte* bytes) {
+    if (c < 0x80) {
+        bytes[0] = c >> 0 & 0x7F | 0x00;
+        return 1;
+    } else if (c < 0x0800) {
+        bytes[0] = c >> 6 & 0x1F | 0xC0;
+        bytes[1] = c >> 0 & 0x3F | 0x80;
+        return 2;
+    } else if (c < 0x010000) {
+        bytes[0] = c >> 12 & 0x0F | 0xE0;
+        bytes[1] = c >> 6 & 0x3F | 0x80;
+        bytes[2] = c >> 0 & 0x3F | 0x80;
+        return 3;
+    } else {
+        bytes[0] = c >> 18 & 0x07 | 0xF0;
+        bytes[1] = c >> 12 & 0x3F | 0x80;
+        bytes[2] = c >> 6 & 0x3F | 0x80;
+        bytes[3] = c >> 0 & 0x3F | 0x80;
+        return 4;
+    }
+}
+
+string wstr2str_utf8(const wstring ws) {
+    vector<char> chars;
+    char buffer[4];
+    for (wchar_t wc : ws) {
+        uint size = encode_utf8((uint)wc, (ubyte*)buffer);
+        for (uint i = 0; i < size; i++) {
+            chars.push_back(buffer[i]);
+        }
+    }
+    return string(chars.data(), chars.size());
+}