public object VisitClassStmt(Stmt.Class stmt)
{
ClassType enclosingClass = _currentClass;
_currentClass = ClassType.CLASS;
Declare(stmt.Name);
Define(stmt.Name);
if (stmt.Superclass != null && stmt.Name.Lexeme.Equals(stmt.Superclass.Name.Lexeme))
{
Lox.Error(stmt.Superclass.Name, "A class cannot inherit from itself.");
}
if (stmt.Superclass != null)
{
_currentClass = ClassType.SUBCLASS;
Resolve(stmt.Superclass);
}
if (stmt.Superclass != null)
{
BeginScope();
_scopes.Peek().Add("super", true);
}
BeginScope();
_scopes.Peek().Add("this", true);
foreach (Stmt.Function method in stmt.Methods)
{
FunctionType declaration = FunctionType.METHOD;
if (method.Name.Lexeme.Equals("init"))
{
declaration = FunctionType.INITIALIZER;
}
ResolveFunction(method, declaration);
}
EndScope();
if (stmt.Superclass != null)
{
EndScope();
}
_currentClass = enclosingClass;
return(null);
}
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);
}
IDictionary <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 @class = new LoxClass(stmt.Name.Lexeme, (LoxClass)superclass, methods);
if (superclass != null)
{
_environment = _environment.Enclosing;
}
_environment.Assign(stmt.Name, @class);
return(null);
}