public object visitClassStmt(Stmt.Class stmt)
{
object superClass = null;
if (stmt.SuperClass != null)
{
superClass = evaluate(stmt.SuperClass);
if (!(superClass is LoxClass))
{
throw new RuntimeError(stmt.SuperClass.Name,
"Superclass must be a class.");
}
}
env.define(stmt.Name.Lexeme, null);
if (stmt.SuperClass != null)
{
env = new Envir(env);
env.define("super", superClass);
}
Dictionary <string, LoxFunction> methods = new Dictionary <string, LoxFunction>();
foreach (Stmt.Function method in stmt.Methods)
{
LoxFunction function = new LoxFunction(method, env,
method.Name.Lexeme == "init");
methods[method.Name.Lexeme] = function;
}
LoxClass klass = new LoxClass(stmt.Name.Lexeme,
(LoxClass)superClass, methods);
if (stmt.SuperClass != null)
{
env = env.Enclosing;
}
env.assign(stmt.Name, klass);
return(null);
}
public void assign(Token name, object value)
{
if (Values.ContainsKey(name.Lexeme))
{
Values[name.Lexeme] = value;
return;
}
if (Enclosing != null)
{
Enclosing.assign(name, value);
return;
}
throw new RuntimeError(name,
$"Undefined variable '{name.Lexeme}'.");
}
