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jb55 2mo ago 💬 8

i love unions in C. they allow you to pack different types of data into the same memory address.

here's an example of an 64-bit string type that you can pass around as a native word on 64-bit systems. it can either be a binmoji or a 6-character null-terminated string.

this enabes the nostrdb metadata table to be super smol. caching reaction counts for any emoji or 6-length string can now be done inplace, only requiring two 64-bit integers worth of storage for each metadata entry, no string tables!

succinct, cache efficient data structures are my happy place

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Adam Soltys 2mo ago

Pretty cool!

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Laser 2mo ago

Python sort of exposes these through their tuple structure?

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jb55 2mo ago 💬 1

python data types are pretty far detached from the hardware. they are all dynamic objects. I don't think python has memory unions.

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Laser 2mo ago

I must have been thinking of Golang's structs w/ unsafe pointers.

Although Python 3 is getting closer:

https://docs.python.org/3/library/struct.html

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Hector E. 2mo ago

Wait until you hear about tagged unions / algebraic data types

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BITKARROT 2mo ago

🎯

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Daniel Wigton 2mo ago

Yes!! One of the first C things I did was make a dll to allow me to do all kinds of unholy reinterpretations of the same data in c#. I can't for the life of me remember why though.

Probably something to do with wanting a single data column in a database that could be used by arbitrary types defined after the fact.

The terrible sins I have committed trying to make a relational database that could handle future types without creating ad hoc tables or columns every time a product was added or changed.

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BITKARROT 2mo ago

moar posts like these !