#include <cppscript>

void clear_history(var history) { history["list"].clear(); }
enable_pickle(clear_history);

void add_history(var history, var line) { history["list"].push_back(line); }
enable_pickle(add_history);

void print_history(var history)
{
	if(history["list"])
		foreach( line, history["list"] ) writeln(line);
	else
		writeln("(history is empty)");
}
enable_pickle(print_history);

var command_history()
{
	return object("command_history").extend
		("clear", clear_history)
		("add", add_history)
		("print", print_history)
		("list", array());
}

var script_main(var lines)
{
	var history;

	try 
	{ 
		history=unpickle_file("history.dat"); 
	}
	catch(var) 
	{ 
		history = command_history(); 
	} 

	if(lines[0] == "clear") 
		history["clear"]();
	else 
		foreach(line, lines) history["add"](line);

	history["print"]();
	pickle_file("history.dat", history);
	return 0;
}