Coerce a `None` value to the default about msgspec HOT 4 OPEN

I don't disagree - big fan of immutable data structures, and the explicit > implicit is true for sure. However - that's the json i got! msgspec is so much faster than pydantic that i gotta ask, at least.

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One thing you could do now is to have a "private" field with optional list and a property that isn't optional.

from msgspec.

That's actually the direction i went, but the setters and append was all a little bit beyond the level of hackery I was willing to commit. If it was a read-only field, the private optional field and non-optional @property would work great. I was going to try to write some sort of helper class that would act like a list and support append, but eh. A bridge too far. Thanks for taking the time to reply though, I appreciate it!

from msgspec.

no prob. I am a big "immutables" fan, so wasn't thinking about the need for mutable fields.

another idea for you then - you can have phantom types, just for deserialization, which will have optional fields and post_init logic. Then you'll just convert from them to the final type to be used in the code. This can be easily automated, either via code generation (explicit approach), or you could even play around with generating the phantom types from the "true" types on the fly

on the topic, I think all the implicit logic, like treating nulls as missing value, is more headache then gain in the long run. pydantic was (or maybe still is) is so confusing with None/Optional handling. As PEP20 says - Explicit is better than implicit.

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