Reliable, high-performance processing with left-fold enumerators Maintained by:haskell@FreeBSD.org Port Added: 08 May 2011 19:08:36 Also Listed In:haskell License: MIT
Typical buffer-based incremental I/O is based around a single loop,
which reads data from some source (such as a socket or file), transforms
it, and generates one or more outputs (such as a line count, HTTP
responses, or modified file). Although efficient and safe, these loops are
all single-purpose; it is difficult or impossible to compose
buffer-based processing loops.
Haskell's concept of "lazy I/O" allows pure code to operate on data from an
external source. However, lazy I/O has several shortcomings. Most notably,
resources such as memory and file handles can be retained for arbitrarily
long periods of time, causing unpredictable performance and error conditions.
Enumerators are an efficient, predictable, and safe alternative to lazy
I/O. Discovered by Oleg Kiselyov, they allow large datasets to be processed
in near constant space by pure code. Although somewhat more complex
to write, using enumerators instead of lazy I/O produces more correct
programs.
This library contains an enumerator implementation for Haskell, designed to
be both simple and efficient.
WWW: https://john-millikin.com/software/enumerator/
To install the port:cd /usr/ports/devel/hs-enumerator/ && make install clean To add the package:pkg_add -r hs-enumerator
Configuration Options
===> The following configuration options are available for hs-enumerator-0.4.19_3:
DOCS=on: Build and/or install documentation
DYNAMIC=on: Add support for dynamic linking
HSCOLOUR=off: Colorize generated documentation by HsColour
PROFILE=off: Add support for profiling
===> Use 'make config' to modify these settings
Reason:
Due to some unexpected dynamic linking problems, Haskell Cabal ports with
binaries that link to their own libraries may not work. With default
configuration, the following ports are known to have this problem:
Agda, BNFC, pandoc, and uuagc. (Their port revision are now bumped.)
In general, it is recommended to rebuild the port if you are
experiencing that the corresponding binary will not start, e.g.:
% agda
Shared object "libHSAgda-2.3.2-ghc7.4.2.so" not found, required by "agda"
2013-02-05
Affects: users of lang/ghc and */hs-*
Author: haskell@FreeBSD.org
Reason:
Note that the recent devel/libffi update caused some breakage in the Haskell
ports with the DYNAMIC option enabled. The problem has been identified and
fixed since then. All Haskell ports have been updated to their latest stable
versions or bumped as DYNAMIC is enabled by default.
Hence it is recommended to rebuild or reinstall all ports depending on GHC
by one of the following commands:
# portmaster -w -r ghc
or
# portupgrade -fr lang/ghc
or
# pkg install -fR lang/ghc
2012-12-20
Affects: users of lang/ghc and */hs-*
Author: haskell@FreeBSD.org
Reason:
Note that the Glorious Glasgow Haskell Compiler has been updated to
version 7.4.2.
Please rebuild or reinstall all dependent ports by issuing one of the
following commands, depending on the tool used:
# portmaster -w -r ghc
or
# portupgrade -fr lang/ghc
or
# pkg install -fR lang/ghc
2012-06-03
Affects: users of lang/ghc and */hs-*
Author: haskell@FreeBSD.org
Reason:
Note that The Glorious Glasgow Haskell Compiler and the Haskell Platform
have been updated to versions 7.4.1 and 2012.2.0.0, respectively. At the
same time, all Haskell ports have been updated to their latest working
versions.
To follow the changes, please issue one of the following commands
(depending on the tool used):
# portmaster -r ghc
or
# portupgrade -fr lang/ghc
2012-02-13
Affects: users of lang/ghc and */hs-*
Author: pgj@FreeBSD.org
Reason:
GHC has been updated to version 7.0.4, and Haskell Platform to version
2011.4.0.0, and other Haskell ports are also updated to their Haskell
Platform versions or latest versions.
To update all affected ports:
# portmaster -r lang/ghc
or
# portupgrade -r lang/ghc
2011-05-09
Affects: users of lang/ghc and */hs-*
Author: ashish@FreeBSD.org
Reason:
GHC has been updated to version 7.0.3 and other Haskell ports are also
updated to their Haskell Platform versions or latest versions.
To update all affected ports:
# portmaster -r lang/ghc
or
# portupgrade -r lang/ghc
Number of commits found: 9
Commit History - (may be incomplete: see SVNWeb link above for full details)
- Fix breakage in the DYNAMIC-enabled ports triggered by the recent
devel/libffi update
- Enable multithreaded build for lang/ghc (i.e. mark MAKE_JOBS_SAFE)
Please note that port revision for all the Haskell ports without version
changes are bumped.
New ports (20):
devel/hs-MonadRandom 0.1.8
devel/hs-base64-conduit 0.5.1
devel/hs-bifunctors 3.2
devel/hs-either 3.1
devel/hs-errors 1.3.1
devel/hs-generic-deriving 1.4.0
(Only the first 15 lines of the commit message are shown above )
- Update The Glorious Glasgow Haskell Compiler to version 7.4.2
- Update Haskell Platform to version 2012.4.0.0
- Update Gtk2Hs to 0.12.4
- Transfer maintainership of math/hs-math-functions to haskell@ [1]
Please note that port revisions for all the Haskell ports without version
changes are bumped.
Some further highlights of the update:
- Trim Makefile headers
- Enable dynamic libraries and dynamic linking by default
- Enable bootstrapping by versions of GHC and HsColour already installed
- Use GCC and binutils from ports
New ports (32):
(Only the first 15 lines of the commit message are shown above )
Bump PORTREVISION of all ports dependent on lang/ghc as during
upgrade, lang/ghc cabal package cache gets invalidated causing all
dependent ports to be reinstalled.
Obtained from: FreeBSD Haskell
Typical buffer-based incremental I/O is based around a single loop,
which reads data from some source (such as a socket or file), transforms
it, and generates one or more outputs (such as a line count, HTTP
responses, or modified file). Although efficient and safe, these loops are
all single-purpose; it is difficult or impossible to compose
buffer-based processing loops.
Haskell's concept of "lazy I/O" allows pure code to operate on data from an
external source. However, lazy I/O has several shortcomings. Most notably,
resources such as memory and file handles can be retained for arbitrarily
long periods of time, causing unpredictable performance and error conditions.
Enumerators are an efficient, predictable, and safe alternative to lazy
I/O. Discovered by Oleg Kiselyov, they allow large datasets to be processed
in near constant space by pure code. Although somewhat more complex
to write, using enumerators instead of lazy I/O produces more correct
programs.
This library contains an enumerator implementation for Haskell, designed to
be both simple and efficient.
WWW: http://john-millikin.com/software/enumerator/
Approved by: pgj (mentor)
Obtained from: FreeBSD Haskell
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