How Much Determinism Should Be Pursued?

[hostilefork]

@hostilefork

We can pick many examples... like whether a MAP! will always enumerate in the same order on different platforms, or with the same contents. Using a deterministically sorted implementation of map would seem to have a number of advantages.

Especially since there's a growing push in software for giving deterministic outputs by default.

I happened across an article discussing what someone felt was lacking in Go:

https://kokada.capivaras.dev/blog/an-unordered-list-of-things-i-miss-in-go/

The title is a joke about how the only option for enumerating maps was to use one with a randomized hash. They felt there should be an option without a third party library where you can explicitly ask for an ordered map.

It also links through to mention that as of Python 3.7, the standard "Dict" dictionary preserves the insertion order:

[Python-Dev] Guarantee ordered dict literals in v3.7?

My historical biases coming from C++ would likely to have been for Go's choice: to actually force randomization in order to prevent people from depending on something they don't care about. This helps fuzz test and make sure the default doesn't overspecify to prevent optimizations of the structure.

But for a higher-level interpreted language in the space of something like Python (or Rebol), that tradeoff may not be the right one for modern concerns.