<!DOCTYPE html><html><head><title></title><style type="text/css">p.MsoNormal,p.MsoNoSpacing{margin:0}</style></head><body><div>I assume if one did not have a null sentinel available they could use `Optional<Principal>` ? <br></div><div><br></div><div>This would be the case of something can be bound but missing correct? Using `Optional` for many might even be more desirable for some that prefer that over dealing with `null` or sentinel. <br></div><div><br></div><div>Part of what makes me concerned with ScopedValue taking `null` is the confusion with existing methods named `ScopedValue.orElse` (I promise I won't go into poly null): <br></div><div><br></div><div>See even if you give `orElse` a nonnull as its second parameter you could still get a `null` in the case that null is bound! <br></div><div><br></div><div>I think that is confusing for folks that have used orElse on `Optional` where if the input is null it will never be null.</div><div><br></div><div>On Thu, Jan 30, 2025, at 11:29 AM, Pedro Lamarão wrote:<br></div><blockquote type="cite" id="qt" style=""><div dir="ltr"><div dir="ltr">Em qui., 30 de jan. de 2025 às 13:21, Adam Gent <<a href="mailto:me@adamgent.com">me@adamgent.com</a>> escreveu:<br></div><div class="qt-gmail_quote qt-gmail_quote_container"><blockquote class="qt-gmail_quote" style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204, 204, 204);padding-left:1ex;"><div>I had assumed for an embarrassing amount of time that ScopedValue would not allow null. So much so that I could not understand why its API looked like Optional.<br></div><div> <br></div><div> Given that ScopedValue goals are to make things easier it seems that not allowing null might be helpful.<br></div><div> <br></div><div> Thoughts?<br></div><div> <br></div><div> (Alan had mentioned on reddit that this topic was OK and I assume I'm posting in the right place. If not advance apologies.)<br></div></blockquote></div><div><br></div><div>Hi Adam!<br></div><div>One of the "classic" examples for ScopedValues is communicating the Principal associated with a session in some framework.<br></div><div>Should we require that frameworks must, for anonymous sessions, set the Principal to some NoPrincipal object instead of null?<br></div><div><br></div><div><span class="qt-gmail_signature_prefix">--</span><br></div><div dir="ltr" class="qt-gmail_signature"><div dir="ltr"><div>Pedro Lamarão<br></div></div></div></div></blockquote><div><br></div></body></html>