Hello
Here is the latest OCaml Weekly News, for the week of May 27 to June 03, 2014.
Archive: https://sympa.inria.fr/sympa/arc/caml-list/2014-05/msg00174.html
Dario Teixeira announced:
I'm happy to announce version 2.0 of PG'OCaml, a library offering type-safe
access to PostgreSQL databases for OCaml applications.
This version no longer depends on Batteries, which hopefully will entice more
Core users to give it a spin. Below is the list of the remaining changes,
straight from the changelog:
* Dario Teixeira and Jacques-Pascal Deplaix: fixing issues with arrays.
This requires all array types to change from 'a array to 'a option array,
which breaks backward compatibility.
* Dario Teixeira's patch making PostgreSQL's NUMERIC type be converted
to/from OCaml strings. This change is not backward's compatible,
requiring a bump in the major version number (though there seems
to be no actual code in the wild relying on the previous behaviour).
* Dario Teixeira's patch adding function 'uuid', which exposes the
unique connection handle identifier.
* Jacques-Pascal Deplaix's patches adding 'catch', 'transact', 'alive',
'inject', and 'alter' functions.
Note that a couple of changes break backward compatibility, hence the new
major version number. These changes were required to fix some long-standing
issues, so I trust you'll be understanding.
This new release should be hitting OPAM soon. Alternatively,
you can grab the source from the project's homepage:
http://pgocaml.forge.ocamlcore.org/
Archive: https://sympa.inria.fr/sympa/arc/caml-list/2014-06/msg00010.html
Yoriyuki Yamagata asked and Xavier Leroy replied:
> Just from the curiosity, why balanced binary trees used in Set and
> Map are AVL-trees, not their alternative, say, red-black trees? Is
> there a deep reason for it, or just a historical one?
At the time Set was written, no efficient algorithms for whole-set
operations (union, intersection, difference, etc) were known for
red-black trees. I'm not sure they are known today.
As for performance of insert/lookup operations, Jean-Christophe
Filliâtre has measurements showing that OCaml's 2-imbalance AVL trees
perform better than red-black trees. It all depends on your ratio of
insertions to lookups, of course. But the 2-imbalance trick makes a
big difference with textbook AVL trees.
Thanks to Alp Mestan, we now include in the OCaml Weekly News the links to the
recent posts from the ocamlcore planet blog at http://planet.ocaml.org/.
OCaml 4.02.0-beta:
http://wodi.forge.ocamlcore.org/2014/05/31/ocaml-4.02beta.html
PG'OCaml 2.0 released:
https://forge.ocamlcore.org/forum/forum.php?forum_id=901
PG'OCaml 2.0 has been released:
http://rwmj.wordpress.com/2014/05/28/pgocaml-2-0-has-been-released/
Announcing PG'OCaml 2.0:
http://nleyten.com/post/2014/05/28/Announcing-PG-OCaml-2.0
Full Time: Software Developer (Functional Programming) at Jane Street in New York, NY; London, UK; Hong Kong:
http://jobs.github.com/positions/0a9333c4-71da-11e0-9ac7-692793c00b45
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