Implement C++ pretty-printer

luprex/core/cpp/util.cpp

@@ -35,6 +35,38 @@ bool is_identifier(const std::string &str) {
     return true;
 }
 
+void quote_string(const std::string &s, std::ostream *os) {
+    bool usesinglequote = false;
+    for (char c : s) {
+        if (c == '"') {
+            usesinglequote = true;
+            break;
+        }
+    }
+    (*os) << (usesinglequote ? '\'' : '"');
+    for (char c : s) {
+        if (c >= 32) {
+            if (c == '"') {
+                (*os) << (usesinglequote ? "\"" : "\\\"");
+            } else if (c == '\'') {
+                (*os) << (usesinglequote ? "\\'" : "'");
+            } else {
+                (*os) << c;
+            }
+        } else {
+            switch (c) {
+            case '\n': (*os) << "\\n"; break;
+            case '\t': (*os) << "\\t"; break;
+            case '\r': (*os) << "\\r"; break;
+            default:
+                (*os) << "\\" << std::setw(3) << int(c);
+                break;
+            }
+        }
+    }
+    (*os) << (usesinglequote ? '\'' : '"');
+}
+
 IdVector id_vector_create(int64_t id1, int64_t id2, int64_t id3, int64_t id4) {
     IdVector result;
     if (id1 >= 0) result.push_back(id1);