Clean up JSON utils in a few ways#14351
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| /** | ||
| * Prevents bugs; see `get` for the same trick. | ||
| */ | ||
| const nlohmann::json * optionalValueAt(const nlohmann::json::object_t && value, const std::string & key) = delete; |
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Ah, it is the same problem as before. This allowed me to fix it.
(Really, this whole function is just an alias for get, and could be deleted.)
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| const nlohmann::json & valueAt(const nlohmann::json::object_t && map, std::string_view key) = delete; | ||
| const nlohmann::json * optionalValueAt(const nlohmann::json::object_t && value, std::string_view key) = delete; |
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Did the delete trick for both of them now
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| const nlohmann::json & valueAt(const nlohmann::json::object_t & map, std::string_view key); | ||
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| std::optional<nlohmann::json> optionalValueAt(const nlohmann::json::object_t & value, const std::string & key); | ||
| std::optional<nlohmann::json> nullableValueAt(const nlohmann::json::object_t & value, const std::string & key); | ||
| /** | ||
| * @return A pointer to the value assiocated with `key` if `value` | ||
| * contains `key`, otherwise return `nullptr` (not JSON `null`!). | ||
| */ | ||
| const nlohmann::json * optionalValueAt(const nlohmann::json::object_t & value, std::string_view key); |
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Using std::string_view is just better, and made GCC happy
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In particular - Remove `get`, it is redundant with `valueAt` and the `get` in `util.hh`. - Remove `nullableValueAt`. It is morally just the function composition `getNullable . valueAt`, not an orthogonal combinator like the others. - `optionalValueAt` return a pointer, not `std::optional`. This also expresses optionality, but without creating a needless copy. This brings it in line with the other combinators which also return references. - Delete `valueAt` and `optionalValueAt` taking the map by value, as we did for `get` in 408c09a, which prevents bugs / unnecessary copies. `adl_serializer<DerivationOptions::OutputChecks>::from_json` was the one use of `getNullable`. I give it a little static function for the ultimate creation of a `std::optional` it does need to do (after switching it to using `getNullable . valueAt`. That could go in `json-utils.hh` eventually, but I didn't bother for now since only one things needs it. Co-authored-by: Sergei Zimmerman <sergei@zimmerman.foo>
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Motivation
In particular
Remove
get, it is redundant withvalueAtand thegetinutil.hh.Remove
nullableValueAt. It is morally just the function compositiongetNullable . valueAt, not an orthogonal combinator like the others.optionalValueAtreturn a pointer, notstd::optional. This also expresses optionality, but without creating a needless copy. This brings it in line with the other combinators which also return references.Delete
valueAtandoptionalValueAttaking the map by value, as we did forgetin 408c09a, which prevents bugs / unnecessary copies.Context
adl_serializer<DerivationOptions::OutputChecks>::from_jsonwas the one use ofgetNullable. I give it a little static function for the ultimate creation of astd::optionalit does need to do (after switching it to usinggetNullable . valueAt. That could go injson-utils.hheventually, but I didn't bother for now since only one things needs it.Add 👍 to pull requests you find important.
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