public object VisitGetExpr(Expr.Get expr)
{
var obj = Evaluate(expr.Obj);
if (obj is LoxInstance li)
{
return(li.Get(expr.Name));
}
throw new RuntimeError(expr.Name, "Only instances have properties");
}
object Expr.IVisitor <object> .Visit(Expr.Get _get)
{
object target = Evaluate(_get.target);
if (target is LoxInstance)
{
return(((LoxInstance)target).Get(_get.name));
}
throw new RuntimeError(_get.name, "Only instances have properties.");
}
public object VisitGetExpr(Expr.Get expr)
{
if (Evaluate(expr.obj) is LoxInstance instance)
{
var value = instance[expr.name];
if (value is LoxFunction function && function.IsGetter)
{
value = function.Call(this, null);
}
return(value);
}
throw new RuntimeError(expr.name, "Only instances have properties");
}
public object visitGetExpr(Expr.Get get)
{
Object _object = evaluate(get._object);
if (_object is LoxInstance && !(_object is LoxClass))
{
object result = ((LoxInstance)_object).get(get.name);
if (result is LoxFunction)
{
if (((LoxFunction)result).isGetter())
{
result = ((LoxFunction)result).call(this, null);
}
}
return(result);
}
throw new Exceptions.RuntimeError(get.name, "Only instances have properties.");
}
private Expr Call()
{
Expr expr = Primary();
while (true)
{
if (Match(TokenType.LEFT_PAREN))
{
expr = FinishCall(expr);
}
else if (Match(TokenType.DOT))
{
Token name = Consume(TokenType.IDENTIFIER, "Expect property name after '.'.");
expr = new Expr.Get(expr, name);
}
else
{
break;
}
}
return(expr);
}
private Expr assignment()
{
Expr expr = ternaryExpression();
if (match(TokenType.EQUALS))
{
Token equals = previous();
Expr value = assignment();
if (expr is Expr.Variable)
{
Token name = ((Expr.Variable)expr).name;
return(new Expr.AssignExpr(name, value));
}
else if (expr is Expr.Get)
{
Expr.Get get = (Expr.Get)expr;
return(new Expr.Set(get._object, get.name, value, get.isCascading));
}
throw error(equals, "Invalid assignment target: " + expr.GetType());
}
return(expr);
}
private Expr Call()
{
Expr expr = Primary();
while (true)
{
if (Match(LEFT_PAREN))
{
// Trying to call previous expr as a function.
expr = FinishCall(expr);
}
else if (Match(DOT))
{
Token name = Consume(IDENTIFIER, "expect property name after '.'.");
expr = new Expr.Get(expr, name);
}
else
{
break;
}
}
return(expr);
}
private Expr call()
{
Expr expr = primary();
while (true)
{
if (match(TokenType.LEFT_PAREN))
{
expr = finishCall(expr);
}
else if (match(TokenType.DOT))
{
Token name = consume(TokenType.IDENTIFIER, "Expect property name after '.'.");
expr = new Expr.Get(expr, name, false);
}
else if (match(TokenType.QUESTION_DOT))
{
Token nil = new Token(TokenType.NIL, "nil", null, -1, -1);
Expr callIfNotNull = new Expr.Get(expr, consume(TokenType.IDENTIFIER, "Expect property after '?."), false);
if (match(TokenType.LEFT_PAREN))
{
callIfNotNull = finishCall(callIfNotNull);
}
expr = new Expr.TernaryExpr(
new Expr.BinaryExpr(expr, new Token(TokenType.EQUALS_EQUALS, "==", null, -1, -1), new Expr.Literal(null, nil)), // ?
new Expr.Literal(null, nil), // :
callIfNotNull); // new Expr.Get(expr, consume(TokenType.IDENTIFIER, "Expect property after '?."), false));
((Expr.TernaryExpr)expr).isNullAccessor = true;
}
else
{
break;
}
}
return(expr);
}
string Expr.IVisitor <string> .Visit(Expr.Get _get)
{
throw new NotImplementedException();
}
public object visitGetExpr(Expr.Get get)
{
resolve(get._object);
return(null);
}
public object VisitGetExpr(Expr.Get expr)
{
Resolve(expr.obj);
return(null);
}
public string visitGetExpr(Expr.Get get)
{
return("(" + get._object.accept(this) + "." + get.name.lexeme + ")");
}
public Void VisitGetExpr(Expr.Get expr)
{
Resolve(expr.Obj);
return(null);
}
public string VisitGetExpr(Expr.Get expr)
{
return($"(value of {expr.Accept(this)})");
}
public object Visit(Expr.Get _get)
{
Resolve(_get.target);
return(null);
}