Readit NewsThe discussion part where you are not allowed (from Terraform lang) to create behavior dependent on the actual values of "Unknown" values (to prevent an ambiguous / non-deterministic plan), reminds of Applicatives vs Monads a bit.
(Sketchy potentially non-100% true illustration ahead)
For example, if you write a command-line parsing library using a Monad, then the set of command-line options is not an upfront fixed set easy to list with --help, but can change depending on previous command line options (here the command line parsing can peek into the upfront "Unknown" values, the options used and their values, to generate even more options).
While if you write it using Applicative, then peeking into the actual values is not possible, you can't create branching behaviour.
The discussion part where you are not allowed (from Terraform lang) to create behavior dependent on the actual values of "Unknown" values (to prevent an ambiguous / non-deterministic plan), reminds of Applicatives vs Monads a bit.
(Sketchy potentially non-100% true illustration ahead)
For example, if you write a command-line parsing library using a Monad, then the set of command-line options is not an upfront fixed set easy to list with --help, but can change depending on previous command line options (here the command line parsing can peek into the upfront "Unknown" values, the options used and their values, to generate even more options).
While if you write it using Applicative, then peeking into the actual values is not possible, you can't create branching behaviour.
Do you have a code example? It would be interesting to see what this kind of code looks like.
Personally, I find complaining about a ”fold over a monad” to be equivalent to complaining about an ”integer indexed loop over an array”. It’s a pretty straightforward implementation detail that have very little to do with your business logic.
And business logic is far, far easier to model using ADTs (it’s literally just AND and OR, applied to data structures) than confounding object inheritance hierarchies.
In fact, I’ve seen a lot more unnecessarily abstracted garbage (usually “design pattern” workarounds to limitations in the object model) in just about every oop based web framework I’ve worked with.
> As more operations are demanded, it is more likely that the existing partitioning of the world into the nice distinct cases won’t suit that operation anymore. Then, as a fix, we can introduce more specific cases, or make existing ones more general - leading to ambiguity, bloat and mental load for the existing operations.
Just an aspect.
Now the question is, investing those few days total saves you more worries. And doesn't derail you. That's hard to evaluate, and I don't attempt to. But for information, $40 is cheap.
[0]: https://treetide.com/book/programming-without-anxiety.html