public void Start(TextReader reader, TextWriter writer)
{
var env = new Environment();
var macroEnv = new Environment();
while (true)
{
writer.Write(Prompt);
var line = reader.ReadLine();
if (string.IsNullOrEmpty(line))
{
return;
}
var l = new Lexer.Lexer(line);
var p = new Parser.Parser(l);
var program = p.ParseProgram();
if (p.Errors.Any())
{
PrintParserErrors(writer, p.Errors);
continue;
}
var evaluator = new Evaluator.Evaluator();
evaluator.DefineMacros(program, macroEnv);
var expanded = evaluator.ExpandMacros(program, macroEnv);
var evaluated = evaluator.Eval(expanded, env);
if (evaluated != null)
{
writer.WriteLine(evaluated.Inspect());
}
}
}
