public object VisitGetExpr(Expr.Get expr)
{
object objekt = Evaluate(expr.Objekt);
if (objekt is BasilInstance)
{
return(((BasilInstance)objekt).Get(expr.Name));
}
throw new RuntimeError(expr.Name, "Only instances have properties.");
}
private Expr Call()
{
Expr expr = Primary();
while (true)
{
if (Match(Token.TokenType.LeftParenthesis))
{
expr = FinishCall(expr);
}
else if (Match(Token.TokenType.Dot))
{
Token name = Consume(Token.TokenType.Identifier, "Expect property name after '.'.");
expr = new Expr.Get(expr, name);
}
else
{
break;
}
}
return(expr);
}
public string VisitGetExpr(Expr.Get expr)
{
throw new System.NotImplementedException();
}
public object VisitGetExpr(Expr.Get expr)
{
Resolve(expr.Objekt);
return(null);
}
private Expr Assignment()
{
Expr expr = Or();
if (Match(Token.TokenType.PlusPlus))
{
Token variable = Previous();
if (expr is Expr.Variable v)
{
Token name = v.name;
return(new Expr.Assign(name,
new Expr.Binary(expr, new Token(Token.TokenType.Plus, "+", null, variable.line), new Expr.Literal(1.0))));
}
else if (expr is Expr.Get)
{
Expr.Get get = (Expr.Get)expr;
return(new Expr.Set(get.Objekt, get.Name, new Expr.Binary(expr, new Token(Token.TokenType.Plus, "+", null, variable.line), new Expr.Literal(1.0))));
}
Error(variable, "Invalid assignment target.");
}
if (Match(Token.TokenType.MinusMinus))
{
Token variable = Previous();
if (expr is Expr.Variable v)
{
Token name = v.name;
return(new Expr.Assign(name,
new Expr.Binary(expr, new Token(Token.TokenType.Plus, "+", null, variable.line), new Expr.Literal(-1.0))));
}
else if (expr is Expr.Get)
{
Expr.Get get = (Expr.Get)expr;
return(new Expr.Set(get.Objekt, get.Name, new Expr.Binary(expr, new Token(Token.TokenType.Plus, "+", null, variable.line), new Expr.Literal(-1.0))));
}
Error(variable, "Invalid assignment target.");
}
if (Match(Token.TokenType.Equal, Token.TokenType.MinusEqual, Token.TokenType.PlusEqual,
Token.TokenType.StarEqual, Token.TokenType.SlashEqual, Token.TokenType.PercentEqual,
Token.TokenType.PlusPlus))
{
Token equals = Previous();
Expr tempValue = Assignment();
Expr assignedValue = tempValue;
switch (equals.type)
{
case Token.TokenType.Equal: break;
case Token.TokenType.MinusEqual:
assignedValue = new Expr.Binary(expr, new Token(Token.TokenType.Minus, "-", null, equals.line), tempValue);
break;
case Token.TokenType.PlusEqual:
assignedValue = new Expr.Binary(expr, new Token(Token.TokenType.Plus, "+", null, equals.line), tempValue);
break;
case Token.TokenType.StarEqual:
assignedValue = new Expr.Binary(expr, new Token(Token.TokenType.Star, "*", null, equals.line), tempValue);
break;
case Token.TokenType.SlashEqual:
assignedValue = new Expr.Binary(expr, new Token(Token.TokenType.Slash, "/", null, equals.line), tempValue);
break;
case Token.TokenType.PercentEqual:
assignedValue = new Expr.Binary(expr, new Token(Token.TokenType.Percent, "%", null, equals.line), tempValue);
break;
default: Basil.Error(Previous().line, "Tried to create assignment statement but tokens were invalid.");
break;
}
if (expr is Expr.Variable v)
{
Token name = v.name;
return(new Expr.Assign(name, assignedValue));
}
else if (expr is Expr.Get)
{
Expr.Get get = (Expr.Get)expr;
return(new Expr.Set(get.Objekt, get.Name, assignedValue));
}
Error(equals, "Invalid assignment target.");
}
//else if (Match(Token.TokenType.MinusEqual))
//{
// Token equals = Previous();
// Expr value = Assignment();
// // replace assignment expression with (expr - value)
// Expr minusEquals = new Expr.Binary(expr, new Token(Token.TokenType.Minus, "-", null, equals.line), value);
// if (expr is Expr.Variable v)
// {
// Token name = v.name;
// return new Expr.Assign(name, minusEquals);
// }
// else if (expr is Expr.Get)
// {
// Expr.Get get = (Expr.Get)expr;
// return new Expr.Set(get.Objekt, get.Name, minusEquals);
// }
// Error(equals, "Invalid assignment target.");
//}
return(expr);
}