private Expr assignment()
{
Expr expr = or();
if (match(TokenType.EQUAL))
{
Token equals = previous();
Expr value = assignment();
if (expr is Expr.Variable)
{
Token name = ((Expr.Variable)expr).name;
return(new Expr.Assign(name, value));
}
else if (expr is Expr.Get)
{
Expr.Get get = (Expr.Get)expr;
return(new Expr.Set(get.object_, get.name, value));
}
error(equals, "Invalid assignment target.");
}
return(expr);
}
public object visitGetExpr(Expr.Get expr)
{
object object_ = evaluate(expr.object_);
if (object_ is LoxInstance)
{
return(((LoxInstance)object_).get(expr.name));
}
throw new RuntimeError(expr.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);
}
public string visitGetExpr(Expr.Get expr)
{
return("");
}
public object visitGetExpr(Expr.Get expr)
{
resolve(expr.object_);
return(null);
}