utils: Introduce catv()

utils.cpp

@@ -214,3 +214,27 @@ std::string utils::trim(std::string_view view)
 	}
 	return std::string{view};
 }
+
+std::string utils::catv(std::string_view view)
+{
+	std::string result;
+	result.reserve(view.length());
+	for(auto c : view)
+	{
+		if (!isascii(c))
+		{
+			result += "M-";
+			result += toascii(c);
+		}
+		else if(iscntrl(c))
+		{
+			result += '^';
+			result += c == '\177' ? '?': c | 0100;
+		}
+		else
+		{
+			result += c;
+		}
+	}
+	return result;
+}