Hello
Here is the latest OCaml Weekly News, for the week of March 18 to 25, 2014.
Archive: https://sympa.inria.fr/sympa/arc/caml-list/2014-03/msg00069.html
David Allsopp announced:
Firstly, many thanks for the various replies to my earlier request for
pointers and guidance on packaging earlier this month.
I'm pleased to announce the release of BitMasks 1.0.0. This library is
designed primarily with C bindings in mind and is yet another solution to
the "how do we manipulate integer bitmask flags functionally" problem. So,
given an integer where bit 0 means something, bit 1 means something else and
bit 2 yet something further, this library allows that to be exposed as type
t = Foo | Bar | Baz and have the integer be constructed as though it were a
set.
This implementation has three key features:
* Underlying type is provided through a functor (so int or int64 or indeed
an arbitrary precision integer can be used)
* There's no copying, so the original integer can still be used (either
internally or, at the whim of the programmer, the integer can be exposed).
This has significant advantages over, for example, returning the a list of
the bits which are set.
* The resulting signature is compatible with Set.S in the standard library
Project home: http://forge.ocamlcore.org/projects/bitmasks/
Repository: https://github.com/meta-stack/bitmasks
OPAM package: bitmasks
The source includes a full example. I believe having looked at other code
out there that Core follows a similar philosophy.
The original motivation for this library was to provide a sane handling for
the myriad masks of information returned by ODBC's SQLGetInfo function, but
I've found it be useful in other bindings as well (particularly for bindings
for some Raspberry Pi components which I hope to release soon) and hope
others may do too.
Happy functional bit set manipulating!
Yaron Minsky then suggested:
You might be interested also in the Flags module in Core_kernel, which
aims to serve a similar purpose.
https://ocaml.janestreet.com/ocaml-core/111.03.00/doc/core_kernel/#Flags
https://github.com/janestreet/core_kernel/blob/master/lib/flags.ml
https://github.com/janestreet/core_kernel/blob/master/lib/flags.mli
https://github.com/janestreet/core_kernel/blob/master/lib/flags_intf.ml
Archive: https://sympa.inria.fr/sympa/arc/caml-list/2014-03/msg00086.html
Jeremie Dimino announced:
I am pleased to announce the 111.06.00 release of the Core suite.
A new package appears with this release: async_ssl. It is an
Async-pipe-based interface with OpenSSL. Bindings to OpenSSL are
written with ctypes.
The following packages were upgraded:
- async_extra
- async_kernel
- async_unix
- core
- core_extended
- core_kernel
- jenga
- re2
- textutils
- typerep
Files and documentation for this release are available on our
website and all packages are in opam:
https://ocaml.janestreet.com/ocaml-core/111.06.00/individual/
https://ocaml.janestreet.com/ocaml-core/111.06.00/doc/
Here is list of changes for this version:
# 111.06.00
## async_extra
- Added `?on_wouldblock:(unit -> unit)` callback to
`Udp.recvmmsg_loop` and `recvmmsg_no_sources_loop`.
- For functions that create `Rpc` connections, added optional
arguments: `?max_message_size:int` and
`?handshake_timeout:Time.Span.t`.
These arguments were already available to `Connection.create`, but
are now uniformly available to all functions that create
connections.
## async_kernel
- Improved the performance of `Pipe.filter_map` by using batching.
## async_ssl
Initial release
## async_unix
- In the `Busy_pollers.t` record, made the `kernel_scheduler` field be
`sexp_opaque`.
Did this so that one doesn't get two copies of the kernel scheduler
in sexps of the scheduler, which already has its own
`kernel_scheduler` field.
## core
- Added inline benchmarks for =Iobuf= and =Time=.
Hera are some of the results from the new benchmarks, with some
indexed tests dropped.
| Name | Time/Run | mWd/Run | Percentage |
|--------------------------------------|----------|---------|------------
|
| [time.ml:Time] Time.to_string | 848.74ns | 249.98w | 100.00% |
| [time.ml:Time] Time.to_ofday | 59.66ns | 38.00w | 7.03% |
| [time.ml:Time] Time.now | 39.78ns | 2.00w | 4.69% |
| [time.ml:Time] Time.Zone.find_office | 83.64ns | 4.00w | 9.85% |
| [time.ml:Time] Time.Span.of_hr | 3.71ns | 2.00w | 0.44% |
| [time.ml:Time] Time.Span.of_min | 3.69ns | 2.00w | 0.44% |
| [time.ml:Time] Time.Span.of_sec | 2.72ns | | 0.32% |
| [time.ml:Time] Time.Span.of_ms | 6.02ns | 2.00w | 0.71% |
| [time.ml:Time] Time.Span.of_ns | 5.98ns | 2.00w | 0.71% |
| Name | Time/Run | Percentage |
|------------------------------------------|----------|------------|
| [iobuf.ml:Blit tests] functor blit:5 | 15.53ns | 7.66% |
| [iobuf.ml:Poke tests] char:0 | 4.11ns | 2.03% |
| [iobuf.ml:Poke tests] uint8:0 | 5.35ns | 2.64% |
| [iobuf.ml:Poke tests] int8:0 | 4.59ns | 2.26% |
| [iobuf.ml:Poke tests] int16_be:0 | 5.19ns | 2.56% |
| [iobuf.ml:Poke tests] int16_le:0 | 5.14ns | 2.53% |
| [iobuf.ml:Poke tests] uint16_be:0 | 5.11ns | 2.52% |
| [iobuf.ml:Poke tests] uint16_le:0 | 5.12ns | 2.53% |
| [iobuf.ml:Poke tests] int32_be:0 | 5.17ns | 2.55% |
| [iobuf.ml:Poke tests] int32_le:0 | 4.91ns | 2.42% |
| [iobuf.ml:Poke tests] uint32_be:0 | 5.73ns | 2.83% |
| [iobuf.ml:Poke tests] uint32_le:0 | 5.74ns | 2.83% |
| [iobuf.ml:Poke tests] int64_be:0 | 5.33ns | 2.63% |
| [iobuf.ml:Poke tests] int64_le:0 | 4.93ns | 2.43% |
| [iobuf.ml:Peek tests] char:0 | 5.50ns | 2.71% |
| [iobuf.ml:Peek tests] uint8:0 | 4.68ns | 2.31% |
| [iobuf.ml:Peek tests] int8:0 | 4.91ns | 2.42% |
| [iobuf.ml:Peek tests] int16_be:0 | 5.19ns | 2.56% |
| [iobuf.ml:Peek tests] int16_le:0 | 4.90ns | 2.42% |
| [iobuf.ml:Peek tests] uint16_be:0 | 5.17ns | 2.55% |
| [iobuf.ml:Peek tests] uint16_le:0 | 5.10ns | 2.51% |
| [iobuf.ml:Peek tests] int32_be:0 | 5.17ns | 2.55% |
| [iobuf.ml:Peek tests] int32_le:0 | 4.92ns | 2.42% |
| [iobuf.ml:Peek tests] uint32_be:0 | 5.45ns | 2.69% |
| [iobuf.ml:Peek tests] uint32_le:0 | 5.46ns | 2.69% |
| [iobuf.ml:Peek tests] int64_be:0 | 6.61ns | 3.26% |
| [iobuf.ml:Peek tests] int64_le:0 | 6.31ns | 3.11% |
- Re-implemented `Thread_safe_queue` to improve performance and reduce
allocation.
The new implementation requires 3 words per element, down from the 7
words required by the old implementation.
The new implementation pools elements so that they can be reused, so
there is no allocation in steady-state use.
The new implementation has `dequeue_exn` rather than `dequeue`, so
that one can dequeue without allocating 2 words.
Eliminated `create'`. One should just use `create` and explicit calls
to `enqueue` and `dequeue_exn`.
Eliminated `dequeue_until_empty`. One should use an explicit while
loop guarded by `length` and using `dequeue_exn`.
Moved `Thread_safe_queue` from `Core_kernel` to `Core`, since it's
thread related.
All in, there is now no allocation in a steady-state usage of
enqueueing and dequeueing elements, as opposed to 9 words per
`enqueue+dequeue` in the old implementation. This reduces the cost
from `enqueue+dequeue` taking 166-216ns to `enqueue+dequeue_exn`
taking 48-82ns (plus eliminating gc impacts). Here are some `BENCH`
results, the first table being the old implementation, and the
second table the new.
| Name | Time/Run | mWd/Run | mjWd/Run |
|------------------------------------------------------------|----------|-
--------|----------|
| [thread_safe_queue.ml] enqueue + dequeue of immediate | 183.89ns |
9.00w | 7.02w |
| [thread_safe_queue.ml] enqueue + dequeue of young object | 216.69ns |
11.00w | 9.01w |
| [thread_safe_queue.ml] enqueue + dequeue_exn of old object | 166.75ns
| 9.00w | 7.02w |
| Name | Time/Run | mWd/Run |
|--------------------------------------------------------------|---------
-|---------|
| [thread_safe_queue.ml] enqueue + dequeue_exn of immediate | 48.20ns |
|
| [thread_safe_queue.ml] enqueue + dequeue_exn of young object | 81.96ns
| 2.00w |
| [thread_safe_queue.ml] enqueue + dequeue_exn of old object | 48.30ns |
|
- Changed `{Bigstring,Iobuf}.recvmmsg_assume_fd_is_nonblocking`, when
no message is available, to return a negative number rather than
raise.
This was done for performance reasons, because raising an exception
is expensive, due to the stashing of the backtrace and the string
creation.
- Added `Iobuf.unsafe_resize`.
- Changed `Bigstring.blit` so that it doesn't release the OCaml lock
on `map_file` bigstrings.
The old behavior of releasing the lock for blits of (small)
bigstrings involving mmapped files was problematic and inconsistent.
Its cost is high, and fundamentally any access to a mapped bigstring
could cause some level of blocking.
- Added time-related `Arg_type.t` values to `Command.Spec`.
- Added module `Type_immediacy`, which has witnesses that express
whether a type's values are always, sometimes, or never immediate.
This code used to be in the `Typerep_immediate` library in typerep.
## core_kernel
- Added inline benchmarks for `Array`
Hera are some of the results from the new benchmarks, with some
indexed tests dropped.
| Name | Time/Run | mWd/Run | mjWd/Run |
|-----------------------------------------------------|-------------|----
-----|-----------|
| [core_array.ml:Alloc] create:0 | 13.65ns | | |
| [core_array.ml:Alloc] create:100 | 99.83ns | 101.00w | |
| [core_array.ml:Alloc] create:255 | 201.32ns | 256.00w | |
| [core_array.ml:Alloc] create:256 | 1_432.43ns | | 257.00w |
| [core_array.ml:Alloc] create:1000 | 5_605.58ns | | 1_001.01w |
| [core_array.ml:Blit.Poly] blit (tuple):10 | 87.10ns | | |
| [core_array.ml:Blit.Poly] blito (tuple):10 | 112.14ns | 2.00w | |
| [core_array.ml:Blit.Poly] blit (int):10 | 85.25ns | | |
| [core_array.ml:Blit.Poly] blito (int):10 | 107.23ns | 2.00w | |
| [core_array.ml:Blit.Poly] blit (float):10 | 84.71ns | | |
| [core_array.ml:Blit.Poly] blito (float):10 | 86.71ns | 2.00w | |
| [core_array.ml:Blit.Int] blit:10 | 19.77ns | | |
| [core_array.ml:Blit.Int] blito:10 | 23.54ns | 2.00w | |
| [core_array.ml:Blit.Float] blit:10 | 19.87ns | | |
| [core_array.ml:Blit.Float] blito:10 | 24.12ns | 2.00w | |
| [core_array.ml:Is empty] Polymorphic '=' | 18.21ns | | |
| [core_array.ml:Is empty] Array.equal | 8.08ns | 6.00w | |
| [core_array.ml:Is empty] phys_equal | 2.98ns | | |
| [core_array.ml:Is empty] Array.is_empty (empty) | 2.98ns | | |
| [core_array.ml:Is empty] Array.is_empty (non-empty) | 3.00ns | | |
- Moved `Thread_safe_queue` to core
- Generalized the type of `Exn.handle_uncaught_and_exit` to `(unit ->
'a) -> 'a`.
In the case where `handle_uncaught_and_exit` succeeds, it can return
the value of the supplied function.
It's type had been:
```ocaml
val handle_uncaught_and_exit : (unit -> never_returns) -> never_returns
```
- Added `Int.round*` functions for rounding to a multiple of another
int.
```ocaml
val round : ?dir:[ `Zero | `Nearest | `Up | `Down ] -> t ->
to_multiple_of:t -> t
val round_towards_zero : t -> to_multiple_of:t -> t
val round_down : t -> to_multiple_of:t -> t
val round_up : t -> to_multiple_of:t -> t
val round_nearest : t -> to_multiple_of:t -> t
```
These functions were added to `Int_intf.S`, implemented by `Int`,
`Nativeint`, `Int32`, and `Int64`.
Various int modules were also lightly refactored to make it easier
in the future to implement common operators available for all
modules implementing the int interface via a functor to share the
code.
## jenga
- Improved the error message when the same library is defined multiple
times.
- Fixed an issue where jenga sometimes would sometimes complain about
a self cycle when `foo.ml` uses a module `Foo`.
- With `-no-notifiers`, jenga doesn't use `inotify` to watch for file
changes. This is useful for linting `jengaroot.ml`.
- Allowed writing jenga rules which restrict dependencies from an
initial conservative approximation to a more accurate set discovered
after an action is run
## re2
- Added `Re2.Std`, so that one should now use `Re2` via `module Re2 =
Re2.Std.Re2`.
At some future date, we will rename the `Regex` module to
`Re2_internal` to force the stragglers to update to the new
convention.
## typerep
- Renamed `Typerep` libraries for more consistency with the rest of
the framework.
```ocaml
Typerep_kernel --> Typerep_lib
Typerep_core --> Typerep_extended
Typereplib --> Typerep_experimental
```
Archive: https://sympa.inria.fr/sympa/arc/caml-list/2014-03/msg00105.html
Francois Berenger announced:
Hopefully soon, itv-tree will be available in OPAM.
The project is here:
https://github.com/UnixJunkie/interval-tree
The interface here:
https://github.com/UnixJunkie/interval-tree/blob/master/lib/interval_tree.mli
An example/test here:
https://github.com/UnixJunkie/interval-tree/blob/master/lib_test/test.ml
I used it successfully to accelerate detection of sphere collisions in
a previous project.
I need it once again in another project to accelerate something else,
so I put it in OPAM this time.
Archive: https://sympa.inria.fr/sympa/arc/caml-list/2014-03/msg00116.html
Sylvain Le Gall announced:
I just released OASIS 0.4.3.
OASIS is a tool to help OCaml developers to integrate configure, build
and install systems in their projects. It should help to create standard
entry points in the source code build system, allowing external tools to
analyse projects easily.
Important changes:
* Added -remove switch to the setup-clean subcommand designed to remove
unaltered generated files completely, rather than simply emptying their
OASIS section.
* Translate path of ocamlfind on Windows to be bash/win32 friendly.
* Description is now parsed in a more structured text (para/verbatim).
New features:
* stdfiles_markdown (alpha): set default extension of StdFiles (AUTHORS,
INSTALL, README) tp be '.md'. Use markdown syntax for standard files.
Use comments that hides OASIS section and digest. This feature should
help direct publishing on GitHub.
* disable_oasis_section (alpha): it allows DisableOASISSection to be
specified in the package with a list of expandable filenames given. Any
generated file specified in this list doesn't get an OASIS section
digest or comment headers and footers and is therefore regenerated each
time `oasis setup` is run (and any changes made are lost). This feature
is mainly intended for use with StdFiles so that, for example,
INSTALL.txt and AUTHORS.txt (which often won't be modified) can have the
extra comment lines removed.
* compiled_setup_ml (alpha): allow to precompile setup.ml to speedup.
Full blog post here:
http://le-gall.net/sylvain+violaine/blog/index.php?post/2014/03/25/Release-of-OASIS-0.4.3
Download here:
https://forge.ocamlcore.org/frs/?group_id=54&release_id=1041
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/.
Release of OASIS 0.4.3:
http://le-gall.net/sylvain+violaine/blog/index.php?post/2014/03/25/Release-of-OASIS-0.4.3
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
Try Mezzo in your browser!:
http://gallium.inria.fr/blog/mezzo-in-the-browser
Statistics:
http://shayne-fletcher.blogspot.com/2014/03/statistics.html
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