public object VisitClassStmt(Stmt.Class stmt)
{
_environment.Define(stmt.Name.Lexeme, null);
object superclass = null;
if (stmt.Superclass != null)
{
superclass = Evaluate(stmt.Superclass);
if (!(superclass is LoxClass))
{
throw new RuntimeError(stmt.Name, "Superclass must be a class.");
}
_environment = new EnvironmentScope(_environment);
_environment.Define("super", superclass);
}
var methods = new Dictionary <string, LoxFunction>();
foreach (var method in stmt.Methods)
{
var function = new LoxFunction(method, _environment, method.Name.Lexeme == "init");
methods[method.Name.Lexeme] = function;
}
var klass = new LoxClass(stmt.Name.Lexeme, (LoxClass)superclass, methods);
if (superclass != null)
{
_environment = _environment.Enclosing;
}
_environment.Assign(stmt.Name, klass);
return(null);
}
public object VisitAssignExpr(Expr.Assign expr)
{
var value = Evaluate(expr.Value);
if (_locals.TryGetValue(expr, out var distance))
{
_environment.AssignAt(distance, expr.Name, value);
}
else
{
_globals.Assign(expr.Name, value);
}
return(value);
}
