Complexity does not equal language features. Sometimes simple is good, but sometimes simple just simply means more bugs in your code.
As a prime example, Go unwillingness to add even the most simple enum kind of type. Having enums (ADTs) with exhaustive pattern matching is NOT complex in any sense or form. It just takes away so, so many bugs you would normally see in production code.
One other low hanging fruit is the fact that zero values are in 90% of all cases not what the dev intended. Sure, the mantra goes "make them useful" but thats hard. How to you know if a value (int) was zero initialised, or if the user did in fact input zero as value. No matter, you will need to validate every one of these "zero values" if you want some sort of robustness.
Adding `null` to C was very simple to add. It added a lot of complexity that the language designer did not see coming (hence the billion dollar mistake he made on that).
`NULL` was originally added to ALGOL back in 1965. C was not even a thing back then. It was obviously a bad choice to port NULL to C, one that ADTs would have perfectly modeled, without the billion dollar cost.
In fact C was built sometime around the early 70s, and at the same time the first MLs where also being developed. One added null, while the other added a better mechanism for "nothingness".
Bottom line is you cant compare "adding null" and adding a feature that is over 50 years old, one that is battle-tested thru generations, and still holds up.
> Go unwillingness to add even the most simple enum kind of type.
Go has enums, under the iota keyword. But I imagine you are really thinking of sum types. Technically Go has those too, but must always have a nil case, which violates what one really wants out of sum types in practice.
Trouble is that nobody has figured out how to implement sum types without a nil/zero case. That is why you haven't seen a more well-rounded construct for the feature yet. This is not an unwillingness from the Go team, it is more of a lack of expertise. Granted, it is an unwillingness from those like yourself who do have the expertise. What stops you from contributing?
> It just takes away so, so many bugs you would normally see in production code.
What bugs do you imagine are making it to production? Each pattern matched case has a behaviour that needs to be tested anyway, so if you missed a case your tests are going to blow up. The construct is useful enough that you don't need to oversell it on imagined hypotheticals.
For example if a have a type with 3 constuctors, and later one new dev adds one more case and forgets to handle it in every call site. No test will catch this 100%, but something like ocaml will just by compiling the program.
I know fo is not (i dont want it to be) like ocaml, bit any modern language should have some of the basic safety features baked in.
> later one new dev adds one more case and forgets to handle it in every call site
Okay, so you are dreaming of a situation where you allow a new developer who doesn't know anything about how to engineer software unfettered access to your codebase and he goes in and starts mucking about to where he ends up doing things that no sensible human would ever consider acceptable?
I accept you like to live dangerously and have no real care for the product you are building. But, still, you've only covered a limited subset of all the similar things this new developer who doesn't know the first thing about building software can make a mess of. Ocaml just isn't going to cut it.
To reach the full gamut you need, say, a proper dependent type system. But are you really going to throw all your Ocaml code away and start writing Rocq just to deal with this guy you should have never let touch your code in the first place? Probably not. So, what now? Your only practical option is to fire him and find someone who actually understands how to write software. And at that point your tests will catch such forgetfulness just fine.
> No test will catch this 100%
Testing cannot exhaust all cases where the search space is infinite as that requires infinite time to evaluate. In this case, you have exactly 4 states. That is evaluated on the order of nanoseconds. If your tests are not capturing every one of those four permutations, it seems clear that you need to stop letting any random Joe who has never done more than some quick vibe coding anywhere near your code. These are solved problems.
And, hell, even if you did switch to a language with a proper type system, like Rocq, so you could mathematically guarantee all aspects of your program, the shitty programmer will still fail to write theorems that are free of holes. So don't think that even lets you of the hook in hiring those who live by the vibes. There is simply no escaping the need for solid engineering.
When you have that, exhaustiveness checking still remains a useful tool, but you aren't going to forget something and ship broken code to production if you don't have it. This isn't a realistic scenario outside of the contrived. Again, The construct is useful enough that you don't need to oversell it on imagined hypotheticals.
> Okay, so you are dreaming of a situation where you allow a new developer who doesn't know anything about how to engineer software unfettered access to your codebase and he goes in and starts mucking about to where he ends up doing things that no sensible human would ever consider acceptable?
Tell me without telling me you have never worked on a large scale business app.
I did long enough to know that in large teams you won't find many accepting of usable type systems. For the same reason the blub developer cannot write good tests, if they can figure out how to write tests at all, they equally fail with types. Which makes sense — testing and types try to solve the exact same problem. The mindset required to grasp and be productive with both is identical. So your imagined hypothetical doesn't even work there. These large scale apps of which you are speak are simply built around constant failure in production. If it is good enough for GitHub...
The only place where the your contrived idea is in any way plausible is where you have a solo developer who thinks he is able to write code without making mistakes or needing to document anything, using a half-assed type system not failing as some kind of proof to himself of that. But in reading this he, unless the hubris is completely off the charts, will be reevaluating that stance.
> you won't find many accepting of usable type systems
I think its not about the "typesystem" but the fear of using something the dev is unfamiliar with. I know people who has written the same code, in the same language for 20+ years. "It worked then, and it will work now" is tattooed on their forehead. Its basic human behaviour, you see this in politics, business and life in general.
> testing and types try to solve the exact same problem
Sure, they overlap.
Tests are just a poor mans types,
Types are just a poor mans tests
But in my mind tests cover the how, and types the what. With both you need less of both. Its a win-win.
> These large scale apps of which you are speak are simply built around constant failure in production.
This is true. But im going to my grave trying to change that. Its an uphill battle.
I gave Lisette a run today. I really like it, its a clear improvement to Go.
Here a few things that i noticed.
- Third party Go code support (like go-chi) is a absolute must have. This is THE feature that will possibly sky-rocket Lisette adoption. So something like stubs etc, maybe something like ReScript has for its JS interop (https://rescript-lang.org/docs/manual/external). The cli tool could probably infer and make these stubs semi-easily, as the go typesystem is kind of simple.
- The HM claim did confuse me. It does not infer when matching on an Enum, but i have to manually type the enum type to get the compiler to agree on what is being matched on. Note, this is a HARD problem (ocaml does this probably the best), and maybe outside the scope of Lisette, but maybe tweak the docs if this is the case. (eg. infers somethings, but not all things)
- Can this be adopted gradually? Meaning a part is Go code, and a part generated from Lisette. Something like Haxe perhaps. This ties to issue 1 (3rd party interop)
But so far this is the BEST compile to Go language, and you are onto something. This might get big if the main issues are resolved.
Variant qualification is a name resolution requirement - Lis follows Rust's scoping model where variants are namespaced under the enum. The implementation correctly infers the type, as shown e.g. in the hint `help: Use Shape.Circle to match this variant` My understanding is HM has nothing to say about this; it operates after names are resolved.
Re: Go third-party packages + incremental adoption, I'll do my best! Thanks for the encouragement.
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