[cwn] Attn: Development Editor, Latest OCaml Weekly News

[Alan Schmitt]

Hello

Here is the latest OCaml Weekly News, for the week of May 24 to 31,
2022.

Table of Contents
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carray.0.0.1
OCaml Users and Developers Workshop 2022
Old CWN


carray.0.0.1
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  Archive: <https://discuss.ocaml.org/t/ann-carray-0-0-1/9938/1>


Danny Willems announced
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  I'm glad to announce the first (experimental) release of ocaml-carray,
  a library mocking the Array interface to work with contiguous C array.
  *Disclaimer*: this first version is experimental and must be used with
  caution. A restricted set of values are supported at the moment
  (custom block with no out-of-heap values). Depending on the demand,
  more values might be supported.  Feel free to use this thread to
  suggest ideas, make opinions, etc.

  Repository
        <https://gitlab.com/dannywillems/ocaml-carray>
  License
        [MIT]
  Release
        [0.0.1]
  Documentation
        <https://dannywillems.gitlab.io/ocaml-carray/carray/index.html>
  Nomadic Labs website
        <https://nomadic-labs.com>
  Tezos ZK-rollups repository
        <https://gitlab.com/nomadic-labs/privacy-team>


[MIT]
<https://gitlab.com/dannywillems/ocaml-carray/-/blob/0.0.1/LICENSE>

[0.0.1] <https://gitlab.com/dannywillems/ocaml-carray/-/tags/0.0.1>

Motivation
╌╌╌╌╌╌╌╌╌╌

  OCaml arrays are not always contiguous piece of memory, requiring
  accessing different chunks of memory when accessing individual
  elements. When requiring a value in memory, the CPU will fetch the RAM
  and load not only the particular value but a memory page (a contiguous
  piece of memory) and add it to its cache. The CPU will use its cache
  to load the values in its registers. It is not efficient with large
  OCaml arrays as the CPU will constantly fetch the RAM to load
  different memory pages in its cache.  Also, when using the C FFI, the
  user must know the memory representation of an array and use the non
  user-friendly low-level interface macro `Field'.


This work
╌╌╌╌╌╌╌╌╌

  This library provides a polymorphic interface mocking a subset of the
  `Array' interface to work with contiguous piece of memory. Using the
  library should be as easy as adding `module Array = Carray'.  A C
  macro `Carray_val' is also provided for developers writing bindings
  and requires to simply cast in the underlying C type.  It has also
  been observed sub arrays are sometimes used for read-only
  operations. However, `Array.sub' allocates a fresh copy of the
  requested sub part. `Carray' leverages this memory cost by providing
  noalloc variants, like `sub_noalloc'.


Performances
╌╌╌╌╌╌╌╌╌╌╌╌

  The concept has been tested and used in real world applications like
  the polynomial library used by Nomadic Labs to implement zk-rollups. A
  speed up of around 50% has been observed when using contiguous arrays
  compared to OCaml arrays to compute NTT/FFT.


Usage
╌╌╌╌╌

  This library is *experimental*. Use this library with caution. The
  interface might change in the future.

  ┌────
  │ opam install carray.0.0.1
  └────


OCaml Users and Developers Workshop 2022
════════════════════════════════════════

  Archive:
  <https://discuss.ocaml.org/t/ocaml-users-and-developers-workshop-2022/9726/2>


Continuing this thread, Matija Pretnar announced
────────────────────────────────────────────────

  This is a reminder for anyone interested in contributing to OCaml
  Workshop 2022. The deadline has been slightly extended to Friday, June
  3 (anywhere on Earth), which means you have roughly *four days left*
  to prepare your submissions.


Old CWN
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  [Alan Schmitt]


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