public object visitFunctionStmt(Stmt.Function stmt)
{
JingleFunc function = new JingleFunc(stmt, environment, false);
environment.define(stmt.name.lexeme, function);
return(null);
}
public int arity()
{
JingleFunc initializer = findMethod("init");
if (initializer == null)
{
return(0);
}
return(initializer.arity());
}
public object call(Interpreter interpreter, List <object> arguments)
{
Instance instance = new Instance(this);
JingleFunc initializer = findMethod("init");
if (initializer != null)
{
initializer.bind(instance).call(interpreter, arguments);
}
return(instance);
}
public object visitSuperExpr(Expr.Super expr)
{
int distance = locals[expr];
JingleClass superclass = (JingleClass)environment.getAt(distance, "super");
Instance object_ = (Instance)environment.getAt(distance - 1, "this");
JingleFunc 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 JingleClass))
{
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, JingleFunc> methods = new Dictionary <string, JingleFunc>();
foreach (Stmt.Function method in stmt.methods)
{
JingleFunc function = new JingleFunc(method, environment, method.name.lexeme.Equals("init"));
methods.Add(method.name.lexeme, function);
}
JingleClass jnclass = new JingleClass(stmt.name.lexeme, (JingleClass)superclass, methods);
if (superclass != null)
{
environment = environment.enclosing;
}
environment.assign(stmt.name, jnclass);
return(null);
}