public int arity()
{
LoxFunction initializer = findMethod("init");
if (initializer == null)
{
return(0);
}
return(initializer.arity());
}
public object call(Interpreter interpreter, List <object> arguments)
{
LoxInstance instance = new LoxInstance(this);
LoxFunction initializer = findMethod("init");
if (initializer != null)
{
initializer.bind(instance).call(interpreter, arguments);
}
return(instance);
}
public object get(Token name)
{
if (fields.ContainsKey(name.lexeme))
{
return(fields[name.lexeme]);
}
LoxFunction method = klass.findMethod(name.lexeme);
if (method != null)
{
return(method.bind(this));// method;
}
throw new RuntimeError(name, "Undefined property '" + name.lexeme + "'.");
}
public object visitSuperExpr(Expr.Super expr)
{
int distance = locals[expr];
LoxClass superclass = (LoxClass)environment.getAt(distance, "super");
// "this" is always one level nearer than "super"'s environment
LoxInstance object_ = (LoxInstance)environment.getAt(distance - 1, "this");
LoxFunction method = superclass.findMethod(expr.method.lexeme);
if (method == null)
{
throw new RuntimeError(expr.method, "Undefined property '" + expr.method.lexeme + "'.");
}
return(method.bind(object_));
}
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.");
}
}
environment.define(stmt.name.lexeme, null);
if (stmt.superclass != null)
{
environment = new Environment(environment);
environment.define("super", superclass);
}
Dictionary <string, LoxFunction> methods = new Dictionary <string, LoxFunction>();
foreach (Stmt.Function method in stmt.methods)
{
LoxFunction function = new LoxFunction(method, environment, method.name.lexeme.Equals("init"));
methods.Add(method.name.lexeme, function);
}
LoxClass klass = new LoxClass(stmt.name.lexeme, (LoxClass)superclass, methods);
if (superclass != null)
{
environment = environment.enclosing;
}
environment.assign(stmt.name, klass);
return(null);
}
