Re: [Caml-list] We need a rich standard library distributed with OCaml, really

[Francois Berenger <francois.berenger@inria.fr>]

On 08/27/2015 04:52 AM, Hongbo Zhang wrote:
> Dear OCaml developers,
>      I would like to spend one hour in writing down my experience that
> why I had to write some small utilities again and again, since this
> happened so many times that I believe you might come across such issues
> before.
>      I am doing some compiler hacking tonight, I needed a utility
> function “String.split” which split a string into a list of strings by
> whitespace, it is just one liner if you use str library. However, since
> I am doing some low level stuff, I would try to avoid such big
> dependency, and I am pretty sure that I have ever written it  for at
> least three times, I just hoped that I could get it done quickly, so I
> am looking into batteries that if I can steal some code, I have to copy
> some code instead of depend on batteries, batteries is too big for my
> projects. `BatString.nsplit` seems to fit for what I needed, I copied
> the definition of `BatString.nsplit` into REPL, no luck, it depends on
> some previously defined functions, then I copied the whole module
> `BatString` into REPL, still no luck, it depended on another module
> `BatReturn`, then I stopped here, it’s time to write my own ad-hoc
> thrown-away `String.split` function again.
>     OCaml is my favorite programming language, and I am very productive
> at it, however, I was annoyed by such things from time to time. We do
> have four *standard libraries* alternatives: batteries, core, extlib and
> ocaml-containers. In my opinion, none of them matches the beauty of the
> OCaml language itself and probably will never catch up if we don’t do
> anything.
>      Note that I don’t want to be offensive to any of these libraries,
> just my personal feedback that why I think it is not a good standard
> library, */I appreciated a lot to people who contribute their precious
> time in maintaining these libraries, better than nothing/* : )
>      - Batteries(extlib)
>        It’s big with dependencies between different modules

For batteries, there is a very interesting proposal from Simon Cruanes 
(a batteries contributor and also the author of ocaml-containers)
about cutting batteries into small pieces.

https://github.com/ocaml-batteries-team/batteries-included/pull/554

 > (OCaml does
> not have a good story in dead code elimination), some of its modules are
> of low quality, for example, batEnum is used everywhere while its
> implementation is buggy.

If we cut into small pieces, maybe we should adopt list and arrays as 
the "glue" to interchange data between modules.
So you can really depend on a single module, if you want to.

 > batIO makes things even worse since it is not
> compatible with standard library, some type signatures mismatched IIRC.

batIO even introduce a performance regression bug compared to the stdlib.
But, it is also easy to avoid; you can always tap into Legacy.*
to access the stdlib things and avoid the batIO layer (when you have
a 'open Batteries' at the top of your file).

>      - ocaml-containers
>        Mostly one man’s project
>      - core
>        I believe core has high quality, however, it suffers the same
> problem as batteries, a big dependency. There is a blocking issue, its
> development process is opaque, for an open source community, I would
> prefer a standard library developed in an open environment.
>      I am not expecting that we could have a  standard library as rich
> as python, but for some utilities, I do believe that shipped with
> standard library or officially supported is the best solution.
>     Thanks — Hongbo

-- 
Regards,
Francois.
"When in doubt, use more types"