static void Main(string[] args)
{
const string prompt = ">> ";
WriteLine($"Hello {Environment.UserName}! This is the Monkey programming language!");
WriteLine("Feel free to type in commands");
// The environment must survive across inputs and remain for as long
// as the REPL is running. Otherwise it wouldn't be possible for
// variables and functions to survive across inputs.
var env = new MonkeyEnvironment();
while (true)
{
Write(prompt);
var line = ReadLine();
var lexer = new Lexer(line);
var parser = new Parser(lexer, false);
var program = parser.ParseProgram();
if (parser.Errors.Count > 0)
{
PrintParserErrors(parser.Errors);
continue;
}
var evaluated = Evaluator.Eval(program, env);
if (evaluated != null)
{
WriteLine(evaluated.Inspect());
}
}
}
private static IMonkeyObject TestEval(string source)
{
var lexer = new Lexer(source);
var parser = new Parser(lexer, false);
var program = parser.ParseProgram();
var env = new MonkeyEnvironment();
return(Evaluator.Eval(program, env));
}
