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Functional programming and reliability: ADTs, safety, critical infrastructure

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Re: Functional programming and reliability: ADTs, safety, critical infrastructure

#2
This article seems to conflate strong type systems with functional programming, except in point 8. It makes sense why- OCaml and Haskell are functional and were early proponents of these type systems. But, languages like Racket don’t have these type systems and the article doesn’t do anything to explain why they are _also_ better for reliability.

Re: Functional programming and reliability: ADTs, safety, critical infrastructure

#3
>In banking, telecom, and payments, reliability is not a nice to have. It is table stakes.

This reliability isn't done by being perfect 100% of the time. Things like being able to handle states where transactions don't line up allowing for payments to eventually be settled. Or for telecom allowing for single parts of the system to not take down the whole thing or adding redundancy. Essentially these types of businesses require fault tolerance to be supported. The real world is messy, there is always going to be faults, so investing heavily into correctness may not be worth it compared to investing into fault tollerance.

Re: Functional programming and reliability: ADTs, safety, critical infrastructure

#4
post #2

This article seems to conflate strong type systems with functional programming, except in point 8. It makes sense why- OCaml and Haskell are functional and were early proponents of these type systems. But, languages like Racket don’t have these type systems and the article doesn’t do anything to explain why they are _also_ better for reliability.

You don't need a strong type system or even really ANY compile-time type system for this strategy to work! I use all these techniques in plain JS and I can still get the benefits of correct-by-construction code style just by freezing objects and failing fast.

Re: Functional programming and reliability: ADTs, safety, critical infrastructure

#6
post #2

This article seems to conflate strong type systems with functional programming, except in point 8. It makes sense why- OCaml and Haskell are functional and were early proponents of these type systems. But, languages like Racket don’t have these type systems and the article doesn’t do anything to explain why they are _also_ better for reliability.

Thank you for saying that. I regularly attend the International Conference on Functional Programming, which grew out of the LISP and Functional Programming conference. Except for the Scheme Workshop, which is the reason I attend, it might as well be called the International Conference on Static Types. Almost all of the benefits of functional programming come from functional programming itself, not from static types, but one would never get that impression from the papers presented there. The types are all that anyone talks about.

Re: Functional programming and reliability: ADTs, safety, critical infrastructure

#8
post #2

This article seems to conflate strong type systems with functional programming, except in point 8. It makes sense why- OCaml and Haskell are functional and were early proponents of these type systems. But, languages like Racket don’t have these type systems and the article doesn’t do anything to explain why they are _also_ better for reliability.

Yeah, I know Rust isn’t everyone’s favorite but I’d expect at least some awareness that we’ve seen a lot of reliability improvements due to many of these ideas in a language which isn’t focused on FP. I ended up closing the tab when they had the example in TypeScript pretending the fix was result types rather than validation: that idea could be expressed as preferring that style, an argument that it makes oversights less likely, etc. but simply ignoring decades and decades of prior art suggests the author either isn’t very experienced or is mostly motivated by evangelism (e.g. COBOL didn’t suffer from the example problem before the first FP language existed so a far more interesting discussion would be demonstrating awareness of alternatives and explaining why this one is better).

Re: Functional programming and reliability: ADTs, safety, critical infrastructure

#9

I'm wary of absolute statements about programming.

I want to be a contrarian and argue with this, but my daily praxis is generally to take a betteridges law approach to most argumentative absolutes and also false dichotomous headlines and question them. Reading the other comments to the effect that the conferences are now strong typing gabfests and insufficiently about FP per se reinforced this feeling.

Reliability should be simpler with FP but so much depends on correctness of the runtime and IO.

Erlang and the "run correctly or die" comes to mind as well. The system is either working or is off. When being off is fatal, Erlang seems to shrug and say "maybe next karmic cycle" maybe this too is a better approach?

Re: Functional programming and reliability: ADTs, safety, critical infrastructure

#10

>In banking, telecom, and payments, reliability is not a nice to have. It is table stakes. This reliability isn't done by being perfect 100% of the time. Things like being able to handle states where transactions don't line up allowing for payments to eventually be settled. Or for telecom allowing for single parts of the system to not take down the whole thing or adding redundancy. Essentially these types of business…

You'd like to know your fault tolerance is reliable and possibly even correct.
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