public static void Start()
{
Object.Environment env = Object.Environment.NewEnvironment();
Object.Environment macroEnv = Object.Environment.NewEnvironment();
for (;;)
{
System.Console.Write(PROMPT);
string line = System.Console.ReadLine();
lexer.Lexer l = lexer.Lexer.New(line);
parser.Parser p = parser.Parser.New(l);
ast.Program program = p.ParseProgram();
if (parser.Parser.Errors().Count != 0)
{
printParserErrors(parser.Parser.Errors());
continue;
}
evaluator.macro_expansion.DefineMacros(program, macroEnv);
ast.Node expanded = evaluator.macro_expansion.ExpandMacros(program, macroEnv);
Object.Object evaluated = evaluator.evaluator.Eval(expanded, env);
if (evaluated != null)
{
System.Console.Write(evaluated.Inspect());
System.Console.WriteLine();
}
}
}
public ast.Program ParseProgram()
{
ast.Program program = new ast.Program {
};
program.Statements = new List <ast.Statement>();
while (!curTokenIs(token.EOF))
{
ast.Statement stmt = parseStatement();
if (stmt != null)
{
program.Statements.Add(stmt);
}
nextToken();
}
return(program);
}
static Object.Object evalProgram(ast.Program program, Object.Environment env)
{
Object.Object result = null;
foreach (ast.Statement statement in program.Statements)
{
result = Eval(statement, env);
if (result is Object.ReturnValue)
{
return(((Object.ReturnValue)result).Value);
}
if (result is Object.Error)
{
return(result);
}
}
return(result);
}