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When you send a message in Erlang, nothing the recipient does with the message impacts anything on the sender side. That's good! In principle, they could have
by eru 24d ago
When you send a message in Erlang, nothing the recipient does with the message impacts anything on the sender side. That's good!
In principle, they could have used something like copy-on-write for this, but in practice they really just make a copy of the bytes.
Alas in Go, when you mutate what you received on a channel, you mutate the object the sender might still be holding. That's pretty annoying. It gets worse, because Golang has no way to declare something as `const` (like in C) nor that you are holding an immutable borrow (like in Rust). So you need to rely on conventions and perhaps a linter.
Slighty less of a tangent: task and channels and software transactional memory (STM) are all great. I see mutexes as more of an implementation detail that you can use to implement these higher level abstractions (but they aren't the only way).
- saghm 24d agoI honestly stopped taking Go channels seriously when I found out that reading from a closed channel is indistinguishable from reading the zero value, but writing to a closed channel will panic. I don't want to have to use booleans and write `true` in order to ping another task and have it tell the difference between getting pinged or being hung up on, and I really don't want to have to architect things so that I need to have my tasks know when the other side of a channel is closed before writing to it (or catch panics instead of using regular error handling) because that feels like it defeats the whole purpose of not needing direct knowledge of the state of the other side. It genuinely seems like those design decisions basically came from a desire to use special operators on channels rather than just having `send` and `receive` methods (or worse, to intentionally avoid "tedious" error handling/optional checks), which is mind-boggling. I hadn't even considered the implications of sending a reference over a channel, but I'll add that to the existing reasons I have to never want to touch Go again.
- eru 23d agoHistorically, Go was also really weird in having a very arrogant design: the language designers allowed themselves a lot of generic operators and structures (like arrays, map, channel, the 'make' function etc), but they were considered taboo for the hoi polloi which had to make do with the equivalent of void* pointers and runtime casting (the empty interface shenanigans). I say historically, because they got generics a while ago.
- saghm 23d agoYeah, I honestly was surprised they did end up eventually getting generics. My brief stint with it ended a while before then, but my impression at the time was that they were bizarrely insistent on trying to come up with a design from first principles rather than taking the time to understand the literal decades of designs that came before. It was impossible for me to tell the difference between their position and "we don't like Java generics and are either not aware of languages like ML or are too arrogant to read about them".