6 ms·

Just out of curiosity, what domain were you working in where "0.0" and "no opinion" were _always_ the same thing? The lack of optionals has infuriated me for ye

Just out of curiosity, what domain were you working in where "0.0" and "no opinion" were _always_ the same thing? The lack of optionals has infuriated me for years and I just can't form a mental model of how anybody ever found this acceptable to work with.

hot_gril 2y ago
Not really one domain in particular, just internal services in general. In many cases, the field is intended to be required in the first place. If not, surprisingly 0 isn't a real answer a lot of the time, so it means none or default: any kind of numeric ID that starts at 1 (like ticket numbers), TTLs, error codes, enums (0 is always UNKNOWN). Similarly with empty strings. I have a hard time thinking of places I really need both 0 and none. The only example that comes to mind is building room numbers, in some room search message where we wanted null to mean wildcard. In those cases, it's not hard to wrap it in a message. Probably the best argument for optionals is when you have a lot of boolean request options where null means default, but even then I prefer instead naming them such that the defaults are all false, since that's clearer anyway. It did take some getting used to and caused some downstream changes to how we design APIs. I think we're better for it because the whole null vs 0 thing can be tedious and error-prone, but it's very opinionated.
- jakjak123 2y ago
  I had the same experience. It was a bit awkward for 6 months, but down the line we learned to design better apis, and dealing with nullable values are tedious at best. Its just easier knowing that a string or integer will _never_ cause a nullpointer.
- kortex 2y ago
  Any time you have a scalar/measurement number, basically any value with physical units, counts, percentages, anything which could be in the denominator of a ratio, those are all strong indicators of a "semantic zero" and you really want to tell the difference between None and 0. They are usually floats, but could be ints (maybe you have number_of_widgets_online, 0 means 0 units, None means "idk".)
  - hot_gril 2y ago
    What's the difference between none inches and 0 inches? Might need a concrete example. We deal with space a fair amount and haven't needed many optionals there.
    - TwentyPosts 2y ago
      They just gave a concrete example: The difference between "we don't know" and "we know that it's zero". Here's another fun one: I've seen APIs where "0.0" was treated as "no value, so take the default value". The default value happened to be 0.2.
- sebastos 2y ago
  Huh, yeah I see. I guess I work more on the robotics side where messages often contain physical or geometric quantities, and that colors my thinking a bit. So "distance to that thing = 0" is a very possible situation, and yet you also want to allow it to say "I didn't measure distance to that thing". And those are very distinct concepts you never want to conflate.
  - hot_gril 2y ago
    I can see that. Or the rare situations where I needed 0 vs null, if for some reason that situation was multiplied times 100, I'd start wanting an optional keyword.
jakjak123 2y ago
Like nearly every time, empty string and 0 for integers can be treated the same as "no value" if you think about it. Are you sending data or sending opinions? Usually to force a choice, you would make a enum or a one-of where the zero-value means the client has forgotten to set it and it can be modelled as a api error. Whether the value was actually on the wire or not is not really that important.
- hot_gril 2y ago
  Yeah, I think it's best to first rethink of null as just, not 0 and not any other number. What that means depends on the context. Tangent: I've seen an antipattern of using enums to describe the "type" of some polymorphic object instead of just using a oneof with type-specific fields. Which gets even worse if you later decide something fits multiple types.
  - jakjak123 2y ago
    I love oneofs in the language with good support, but they are woeful in Golang and the "official" grpc-web message types.
- kortex 2y ago
  0 as a default for "no int" is tolerable, 0.0 as a default for "no float" is an absolute nightmare in any domain remotely related to math, machine learning, or data science. We dealt with a bug that for weeks was silently corrupting the results of trials pitting the performance of various algos against each other. Because a valid response was "no reply/opt out", combined with a bug in processing the "opt out" enum, also combined with a bug in score aggregation, functions were treated like they replied "0.0" instead of "confidence = None". It really should have defaulted NaN for missing floats.
  - hot_gril 2y ago
    What about floats made this a problem? We're treating 0.0 specially in some places.
  - 2y ago

hot_gril 2y ago

Not really one domain in particular, just internal services in general. In many cases, the field is intended to be required in the first place. If not, surprisingly 0 isn't a real answer a lot of the time, so it means none or default: any kind of numeric ID that starts at 1 (like ticket numbers), TTLs, error codes, enums (0 is always UNKNOWN). Similarly with empty strings. I have a hard time thinking of places I really need both 0 and none. The only example that comes to mind is building room numbers, in some room search message where we wanted null to mean wildcard. In those cases, it's not hard to wrap it in a message. Probably the best argument for optionals is when you have a lot of boolean request options where null means default, but even then I prefer instead naming them such that the defaults are all false, since that's clearer anyway. It did take some getting used to and caused some downstream changes to how we design APIs. I think we're better for it because the whole null vs 0 thing can be tedious and error-prone, but it's very opinionated.

jakjak123 2y ago
I had the same experience. It was a bit awkward for 6 months, but down the line we learned to design better apis, and dealing with nullable values are tedious at best. Its just easier knowing that a string or integer will _never_ cause a nullpointer.
kortex 2y ago
Any time you have a scalar/measurement number, basically any value with physical units, counts, percentages, anything which could be in the denominator of a ratio, those are all strong indicators of a "semantic zero" and you really want to tell the difference between None and 0. They are usually floats, but could be ints (maybe you have number_of_widgets_online, 0 means 0 units, None means "idk".)
- hot_gril 2y ago
  What's the difference between none inches and 0 inches? Might need a concrete example. We deal with space a fair amount and haven't needed many optionals there.
  - TwentyPosts 2y ago
    They just gave a concrete example: The difference between "we don't know" and "we know that it's zero". Here's another fun one: I've seen APIs where "0.0" was treated as "no value, so take the default value". The default value happened to be 0.2.
sebastos 2y ago
Huh, yeah I see. I guess I work more on the robotics side where messages often contain physical or geometric quantities, and that colors my thinking a bit. So "distance to that thing = 0" is a very possible situation, and yet you also want to allow it to say "I didn't measure distance to that thing". And those are very distinct concepts you never want to conflate.
- hot_gril 2y ago
  I can see that. Or the rare situations where I needed 0 vs null, if for some reason that situation was multiplied times 100, I'd start wanting an optional keyword.

jakjak123 2y ago

Like nearly every time, empty string and 0 for integers can be treated the same as "no value" if you think about it. Are you sending data or sending opinions? Usually to force a choice, you would make a enum or a one-of where the zero-value means the client has forgotten to set it and it can be modelled as a api error. Whether the value was actually on the wire or not is not really that important.

hot_gril 2y ago
Yeah, I think it's best to first rethink of null as just, not 0 and not any other number. What that means depends on the context. Tangent: I've seen an antipattern of using enums to describe the "type" of some polymorphic object instead of just using a oneof with type-specific fields. Which gets even worse if you later decide something fits multiple types.
- jakjak123 2y ago
  I love oneofs in the language with good support, but they are woeful in Golang and the "official" grpc-web message types.
kortex 2y ago
0 as a default for "no int" is tolerable, 0.0 as a default for "no float" is an absolute nightmare in any domain remotely related to math, machine learning, or data science. We dealt with a bug that for weeks was silently corrupting the results of trials pitting the performance of various algos against each other. Because a valid response was "no reply/opt out", combined with a bug in processing the "opt out" enum, also combined with a bug in score aggregation, functions were treated like they replied "0.0" instead of "confidence = None". It really should have defaulted NaN for missing floats.
- hot_gril 2y ago
  What about floats made this a problem? We're treating 0.0 specially in some places.
- 2y ago