4 ms·

I keep thinking there must be great potential for using the ML Module system to create high-performance, customize-at-compile-time libraries, like C++ template

I keep thinking there must be great potential for using the ML Module system to create high-performance, customize-at-compile-time libraries, like C++ template libraries but without the messiness and potentially even more expressive. But I've had a hard time finding SML or OCaml projects that advertise this as a benefit. Does anyone know of a project that's achieved this? Maybe many do, but don't state it that way explicitly?

Avshalom 10y ago
I think that's what fftw does
- jasperry 10y ago
  Interesting, however, it emits C code, and the paper makes no reference to the module system as what's being leveraged about ML. http://www.fftw.org/pldi99.pdf http://www.fftw.org/pldi99.pdf
jlouis 10y ago
This is what MLton essentially does as a system. It will expand away every module use such that they have no runtime overhead, but only exist in order to organize code. This allows you to build software consisting of many small functors which are composed together to form the final program. It is perhaps the reason to invest time in OCaml or Standard ML. But it requires a compiler which can reap the benefit as well. Newer versions of OCaml, with flambda as a backend, also help with this and gives you some of the advantages of full-module-expansion. In practice, any decently sized OCaml or Standard ML program written by someone fluent in the module system would be an example project. Unfortunately, most of these I know about doesn't live in the Open Source world where I can just point to them. (Disclaimer: I was involved somewhat with MLton)
- metafunctor 10y ago
  There's the MLton Library project: https://github.com/MLton/mltonlib https://github.com/MLton/mltonlib
dwenzek 10y ago
MirageOS arguments its choice of OCaml in these terms: "the module system is among the most powerful in a general-purpose programming language in terms of permitting flexible and safe code reuse and refactoring" https://mirage.io/wiki/technical-background https://mirage.io/wiki/technical-background
Drup 10y ago
I've wanted to write a blog post for a while, that would list the various advanced usage of the module system in OCaml. Mirage has already been cited, see also [1]. Another example is ocamlgraph [2]. I have an old reddit post that attempted to make a list [3]. [1]: https://mirage.io/blog/introducing-functoria https://mirage.io/blog/introducing-functoria [2]: http://ocamlgraph.lri.fr/index.en.html http://ocamlgraph.lri.fr/index.en.html [3]: https://dd.reddit.com/r/ocaml/comments/364vqg/examples_of_ocaml_modules_which_cant_be_done_in/craziqb https://dd.reddit.com/r/ocaml/comments/364vqg/examples_of_oc...
- jasperry 10y ago
  Thanks, these are great references, especially the last one. I would definitely read that blog post.

Avshalom 10y ago

I think that's what fftw does

jasperry 10y ago
Interesting, however, it emits C code, and the paper makes no reference to the module system as what's being leveraged about ML. http://www.fftw.org/pldi99.pdf http://www.fftw.org/pldi99.pdf

jlouis 10y ago

This is what MLton essentially does as a system. It will expand away every module use such that they have no runtime overhead, but only exist in order to organize code. This allows you to build software consisting of many small functors which are composed together to form the final program. It is perhaps the reason to invest time in OCaml or Standard ML. But it requires a compiler which can reap the benefit as well. Newer versions of OCaml, with flambda as a backend, also help with this and gives you some of the advantages of full-module-expansion. In practice, any decently sized OCaml or Standard ML program written by someone fluent in the module system would be an example project. Unfortunately, most of these I know about doesn't live in the Open Source world where I can just point to them. (Disclaimer: I was involved somewhat with MLton)

metafunctor 10y ago
There's the MLton Library project: https://github.com/MLton/mltonlib https://github.com/MLton/mltonlib

dwenzek 10y ago

MirageOS arguments its choice of OCaml in these terms: "the module system is among the most powerful in a general-purpose programming language in terms of permitting flexible and safe code reuse and refactoring" https://mirage.io/wiki/technical-background https://mirage.io/wiki/technical-background

Drup 10y ago

I've wanted to write a blog post for a while, that would list the various advanced usage of the module system in OCaml. Mirage has already been cited, see also [1]. Another example is ocamlgraph [2]. I have an old reddit post that attempted to make a list [3]. [1]: https://mirage.io/blog/introducing-functoria https://mirage.io/blog/introducing-functoria [2]: http://ocamlgraph.lri.fr/index.en.html http://ocamlgraph.lri.fr/index.en.html [3]: https://dd.reddit.com/r/ocaml/comments/364vqg/examples_of_ocaml_modules_which_cant_be_done_in/craziqb https://dd.reddit.com/r/ocaml/comments/364vqg/examples_of_oc...

jasperry 10y ago
Thanks, these are great references, especially the last one. I would definitely read that blog post.