Primitive streams and optional (original) (raw)

Remi Forax forax at univ-mlv.fr
Sun Nov 25 10:06:06 PST 2012

On 11/25/2012 07:02 PM, Tim Peierls wrote:

On Sun, Nov 25, 2012 at 12:25 PM, Remi Forax <forax at univ-mlv.fr_ _<mailto:forax at univ-mlv.fr>> wrote:

This would be more appealing with OptionalXxx, moving the Supplier argument away from the stream and onto the Optional object itself: return s.least().or(() -> computeDefaultValue());

sorry, but why do you want to create an Optional if there is no option. When you provide a supplier, if there is no result, the supplier is called to provide one so at the end there is always a value. I like intermediary state in a builder only when necessary. When I use "Optional" I mean specifically the Guava semantics. I think it's worth the extra object creation to be able to simplify the stream API. I understand that Doug and others disagree violently with me. :-) Optional is interesting only if it's a pseudo class recognized by the language that let you call any methods you want on it, i.e. if Optional acts as a reified null object. We are far from that. Straw man argument.

ask yourself why Guava's Optional declares a method transform() by example.

--tim

Rémi

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