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I've never encountered a real OCaml project or anyone who uses it in my career (same is true for Haskell). I have assumed these languages are a hobby for CS aca

I've never encountered a real OCaml project or anyone who uses it in my career (same is true for Haskell). I have assumed these languages are a hobby for CS academics and get used for pet projects by their devotees. Not that that's bad - they're interesting and the ideas are cool. I would just be afraid of locking myself into an isolated ecosystem that it's hard to hire experienced people for. Is anyone on HN actually using these languages for scientific computing, or other large production projects? Curious to know what the pros / cons are in practice and how common that is.

non-entity 6y ago
I've talked to at least one persons who works on production Haskell applications, and Jane Street, a company that was discussed on HN just yesterday makes heavy use of OCaml, but yeah they're pretty rare and I suppose the people working with them are just lucky. I've heard particularly about the Haskell market that if you want a chance of competing for the few jobs available you have to be among the top-haskellers, but I'm not sure.
- Tarq0n 6y ago
  Jane Street being the only company that anyone ever mentions when discussing OCaml is even worse in my opinion. It means the ecosystem is going to be heavily driven by their needs, not to mention that banks tend to have idiosyncratic development cultures.
  - mseri 6y ago
    It is not the only one though. There are Ahrefs, Tarides, Tezos, Citrix (XenServer and a part of Xen are in OCaml), Inria, Facebook (for compilers, typecheckers and ReasonML), Bloomberg (was Bucklescript/ReScript, now at facebook though I believe). There are also some academic projects with industrial uses. Directly to mind come Coq, Frama-C, Mirage and the Zélus compiler. EDIT: added Inria and Frama-C
  - brmgb 6y ago
    JaneStreet is not the only user of OCaml. Both INRIA and the CEA uses OCaml heavily (Coq, CompCert, Frama-C). Cambridge uses it for MirageOS, Facebook to write software analysers and now web applications (the web version of Facebook Messenger), Citrix in XenServer. Bloomberg developed a compiler from OCaml to Javascript.
  - logarhythmic 6y ago
    Facebook also uses it and will probably have more of an emphasis on it now with their ReasonML project
  - Shoreleave 6y ago
    Jane Street only gets mentioned so often because it is one of the highest paying and selective companies in the world. They are not in control of the ecosystem. And they have nothing to do with banks.
  - yawaramin 6y ago
    Docker for Mac uses OCaml for a critical virtualization layer. So does every cloud compute provider that runs on Xen virtualization: https://twitter.com/yawaramin/status/1284976603454492674 https://twitter.com/yawaramin/status/1284976603454492674
- x87678r 6y ago
  Jane Street has 900 employees, I'm guessing 600 in US and maybe 200 devs at most.
7thaccount 6y ago
I'm not very familiar with the scientific landscape of Haskell or OCaml, but if you would allow an educated guess... Languages like R, Python, Matlab, and Mathematica have a LOT of built-in capability in this area to do symbolic and numerical methods and data analysis kind of stuff (large sparse matrices... etc). You can do a ton in the high level language without ever dropping down to C or Fortran. So a scientist can just do their job without having to worry about how the plumbing works as others (open source community for Python and R) or vendors (Matlab and Mathematica) take care of that, which is a huge win. Back when I thought about doing scientific work in Ada, Rust, OCaml, and Haskell, I was dissapointed to see that either there were many libraries missing that I would need, or the existing ones were incomplete. The solution is usually just to FFI to Python or C, but at that point, I think you lose a lot of the magic of sticking to 1 high level language. Just my 2 cents. If you're comfortable in doing all the scientific bits in C and just calling from OCaml, then you should be fine. On the data analysis side though, R or Python + Pandas just have sooo much inertia. I'll add that this book's table of contents seems to have some really neat topics, but a lot are just a single page long and I still think a lot of areas (Ex: linear algebra) are going to be a lot less complete than what Python has to offer. With that being said, the scientific scene I'm seeing in this book is much farther along than I would've guessed, so that is a good sign.
- mseri 6y ago
  I am part of Owl contributors/maintainers. You are right that the ecosystem is small, and will likely be always behind Python, R and Julia. But considering how small the community around numerical methods in OCaml is, I think the work that went into owl and this book is incredible and may help raising awareness and growing the userbase. I think one of our current limitations is the lack of a high quality, full-featured plotting library. There are some which are used for publication level plots, but they are nowhere near the experience of plotly, matplotlib, ggplot2 or julia's plots. In any case, the community seems to be slowly growing already, so there is some hope. I think the best would be if we can start integrating it with SciML and similar projects.
  - 7thaccount 6y ago
chalst 6y ago
OCaml is the strongly-typed functional language that sees most serious use. It's harder to do generic polymorphism in OCaml since the language has nothing like C++'s parametric templates or Haskell's type classes. It does have a very nice module system that has the required flexibility, but compared to these languages, I think it is clunky for the kind of genericity seen in scientific computing. I think Julia has shown us that strong typing is not really needed for scientific computing.
- brmgb 6y ago
  > It's harder to do generic polymorphism in OCaml since the language has nothing like C++'s parametric templates or Haskell's type classes. It does have a very nice module system that has the required flexibility, but compared to these languages, I think it is clunky for the kind of genericity seen in scientific computing. Are parametrized modules really clunkier than parametric templates ?
  - steev 6y ago
    At least for beginners, they absolutely are. I have found undergrads generally get the idea behind something like HashMap<Integer, String> but getting them to reason about OCaml modules takes quite a bit of effort.
    - gopiandcode 6y ago
      (int, string) Map.t doesn't seem to be too many steps away from your example. When I was learning OCaml, I found that much of the module and module type system can just be seen as a more beefed up version of interfaces in OOP languages, so it didn't take long to see its benefits.
- ziotom78 6y ago
  > I think Julia has shown us that strong typing is not really needed for scientific computing. I think you meant static typing, in opposition to dynamic. Julia is strongly typed like OCaml.
philzook 6y ago
I use OCaml at work. We work with the Binary Analysis Platform https://github.com/BinaryAnalysisPlatform/bap https://github.com/BinaryAnalysisPlatform/bap which is a pretty essential part of what we do. In general, OCaml seems somewhat popular in the area of compilers and program analysis. Facebook Infer is written in OCaml for example https://fbinfer.com/ https://fbinfer.com/. This may be as you said because of these areas sometimes more academic flavor. There are companies out there using OCaml for all sorts of things, although of course it is a small fraction of those using python or C++.
Ixiaus 6y ago
Haskell and OCaml are definitely not just hobbies. I've used Haskell full-time for the last five years of my career. The company I work for uses Haskell for a network packet parsing engine, web api servers, CLI executables, build infrastructure (alongside Nix and NixOS), an interpreter for a custom programming language, a gateway/proxy service for AWS services, etc.
deleted 6y ago
[deleted]
agumonkey 6y ago
Bad statistics sorry.
rwmj 6y ago
We've written a bunch of virt tools in OCaml, used by hundreds of customers. eg: https://github.com/libguestfs/virt-v2v https://github.com/libguestfs/virt-v2v
gnufx 6y ago
An example of OCaml use in scientific computing is to derive the framework for the FFTW library, which is rather important. (No, the library isn't written in OCaml, as I've seen claimed.)

non-entity 6y ago

I've talked to at least one persons who works on production Haskell applications, and Jane Street, a company that was discussed on HN just yesterday makes heavy use of OCaml, but yeah they're pretty rare and I suppose the people working with them are just lucky. I've heard particularly about the Haskell market that if you want a chance of competing for the few jobs available you have to be among the top-haskellers, but I'm not sure.

Tarq0n 6y ago
Jane Street being the only company that anyone ever mentions when discussing OCaml is even worse in my opinion. It means the ecosystem is going to be heavily driven by their needs, not to mention that banks tend to have idiosyncratic development cultures.
- mseri 6y ago
  It is not the only one though. There are Ahrefs, Tarides, Tezos, Citrix (XenServer and a part of Xen are in OCaml), Inria, Facebook (for compilers, typecheckers and ReasonML), Bloomberg (was Bucklescript/ReScript, now at facebook though I believe). There are also some academic projects with industrial uses. Directly to mind come Coq, Frama-C, Mirage and the Zélus compiler. EDIT: added Inria and Frama-C
- brmgb 6y ago
  JaneStreet is not the only user of OCaml. Both INRIA and the CEA uses OCaml heavily (Coq, CompCert, Frama-C). Cambridge uses it for MirageOS, Facebook to write software analysers and now web applications (the web version of Facebook Messenger), Citrix in XenServer. Bloomberg developed a compiler from OCaml to Javascript.
- logarhythmic 6y ago
  Facebook also uses it and will probably have more of an emphasis on it now with their ReasonML project
- Shoreleave 6y ago
  Jane Street only gets mentioned so often because it is one of the highest paying and selective companies in the world. They are not in control of the ecosystem. And they have nothing to do with banks.
- yawaramin 6y ago
  Docker for Mac uses OCaml for a critical virtualization layer. So does every cloud compute provider that runs on Xen virtualization: https://twitter.com/yawaramin/status/1284976603454492674 https://twitter.com/yawaramin/status/1284976603454492674
x87678r 6y ago
Jane Street has 900 employees, I'm guessing 600 in US and maybe 200 devs at most.

7thaccount 6y ago

I'm not very familiar with the scientific landscape of Haskell or OCaml, but if you would allow an educated guess... Languages like R, Python, Matlab, and Mathematica have a LOT of built-in capability in this area to do symbolic and numerical methods and data analysis kind of stuff (large sparse matrices... etc). You can do a ton in the high level language without ever dropping down to C or Fortran. So a scientist can just do their job without having to worry about how the plumbing works as others (open source community for Python and R) or vendors (Matlab and Mathematica) take care of that, which is a huge win. Back when I thought about doing scientific work in Ada, Rust, OCaml, and Haskell, I was dissapointed to see that either there were many libraries missing that I would need, or the existing ones were incomplete. The solution is usually just to FFI to Python or C, but at that point, I think you lose a lot of the magic of sticking to 1 high level language. Just my 2 cents. If you're comfortable in doing all the scientific bits in C and just calling from OCaml, then you should be fine. On the data analysis side though, R or Python + Pandas just have sooo much inertia. I'll add that this book's table of contents seems to have some really neat topics, but a lot are just a single page long and I still think a lot of areas (Ex: linear algebra) are going to be a lot less complete than what Python has to offer. With that being said, the scientific scene I'm seeing in this book is much farther along than I would've guessed, so that is a good sign.

mseri 6y ago
I am part of Owl contributors/maintainers. You are right that the ecosystem is small, and will likely be always behind Python, R and Julia. But considering how small the community around numerical methods in OCaml is, I think the work that went into owl and this book is incredible and may help raising awareness and growing the userbase. I think one of our current limitations is the lack of a high quality, full-featured plotting library. There are some which are used for publication level plots, but they are nowhere near the experience of plotly, matplotlib, ggplot2 or julia's plots. In any case, the community seems to be slowly growing already, so there is some hope. I think the best would be if we can start integrating it with SciML and similar projects.
- 7thaccount 6y ago

chalst 6y ago

OCaml is the strongly-typed functional language that sees most serious use. It's harder to do generic polymorphism in OCaml since the language has nothing like C++'s parametric templates or Haskell's type classes. It does have a very nice module system that has the required flexibility, but compared to these languages, I think it is clunky for the kind of genericity seen in scientific computing. I think Julia has shown us that strong typing is not really needed for scientific computing.

brmgb 6y ago
> It's harder to do generic polymorphism in OCaml since the language has nothing like C++'s parametric templates or Haskell's type classes. It does have a very nice module system that has the required flexibility, but compared to these languages, I think it is clunky for the kind of genericity seen in scientific computing. Are parametrized modules really clunkier than parametric templates ?
- steev 6y ago
  At least for beginners, they absolutely are. I have found undergrads generally get the idea behind something like HashMap<Integer, String> but getting them to reason about OCaml modules takes quite a bit of effort.
  - gopiandcode 6y ago
    (int, string) Map.t doesn't seem to be too many steps away from your example. When I was learning OCaml, I found that much of the module and module type system can just be seen as a more beefed up version of interfaces in OOP languages, so it didn't take long to see its benefits.
ziotom78 6y ago
> I think Julia has shown us that strong typing is not really needed for scientific computing. I think you meant static typing, in opposition to dynamic. Julia is strongly typed like OCaml.

philzook 6y ago

I use OCaml at work. We work with the Binary Analysis Platform https://github.com/BinaryAnalysisPlatform/bap https://github.com/BinaryAnalysisPlatform/bap which is a pretty essential part of what we do. In general, OCaml seems somewhat popular in the area of compilers and program analysis. Facebook Infer is written in OCaml for example https://fbinfer.com/ https://fbinfer.com/. This may be as you said because of these areas sometimes more academic flavor. There are companies out there using OCaml for all sorts of things, although of course it is a small fraction of those using python or C++.

Ixiaus 6y ago

Haskell and OCaml are definitely not just hobbies. I've used Haskell full-time for the last five years of my career. The company I work for uses Haskell for a network packet parsing engine, web api servers, CLI executables, build infrastructure (alongside Nix and NixOS), an interpreter for a custom programming language, a gateway/proxy service for AWS services, etc.

deleted 6y ago

[deleted]

agumonkey 6y ago

Bad statistics sorry.

rwmj 6y ago

We've written a bunch of virt tools in OCaml, used by hundreds of customers. eg: https://github.com/libguestfs/virt-v2v https://github.com/libguestfs/virt-v2v

gnufx 6y ago

An example of OCaml use in scientific computing is to derive the framework for the FFTW library, which is rather important. (No, the library isn't written in OCaml, as I've seen claimed.)