Differences from Arch
=====================

This page will describe key differences between darcs and
`Arch <http://wiki.gnuarch.org>`_.

[[`TableOfContents <TableOfContents>`_([2])]]

darcs makes it easier to send patches by e-mail
-----------------------------------------------

Arch lacks an equivalent to ``darcs send``to send an official Arch
'changeset' via e-mail. Its
`been discussed <http://lists.gnu.org/archive/html/gnu-arch-users/2004-04/msg00650.html>`_
as a desired feature for Arch, but hasn't shown up yet. Darcs has
it now. :)
*As a new user and contributor, this has been my favorite feature of darcs to discover. -- `MarkStosberg <MarkStosberg>`_*

Arch is more complex and difficult to learn
-------------------------------------------

Arch has more commands, more steps to setup a new project, and even
longer more complex file and directory names. :) There are number
of active projects now to make a simpler and easier to use
interface to Arch, but none claim to be stable or mature yet.

darcs preserves individual patches when merging
-----------------------------------------------

As Martin Pool describes in
`what's wrong with Arch <http://sourcefrog.net/weblog/software/vc/arch/whats-wrong.html>`_,
merging from one branch to another can produce a single big patch.
In darcs, each individual patch is preserved, allowing you to merge
5 patches from another repository all at once, and later
``"unpull"``just one of the patches.

You can also read
`more discussion of how darcs patch merging works versus arch <http://article.gmane.org/gmane.comp.version-control.arch.user/30675>`_.

Arch has no command to find the changesets that touched a particular file
-------------------------------------------------------------------------

With darcs this is easy: ``darcs changes file.txt``

darcs stores all the metadata for a repo in one place
-----------------------------------------------------

With Arch, you can have ``.arch-ids``directories littered
throughout the source tree. With darcs, all metadata is stored in

::

    _darcs

in the top level directory. This has the benefit that ordinary Unix
utilities which traverse source directories do not stumble into
metadata directories.

darcs has better Win32 support
------------------------------

Darcs builds directly on win32 systems with all of its features.
Win32 support for Arch is present, but currently being maintained
on a branch with a
`number of open TODO items <http://wiki.gnuarch.org/moin.cgi/tla_20win32_20todo>`_.
Both darcs and Arch have slower performance on win32.

Arch tracks changes in file permissions, darcs does not
-------------------------------------------------------

Arch keeps file system meta information it's repository, notably
file permissions. Darcs does not.

There is probably a way to use
`mtree <http://www.openbsd.org/cgi-bin/man.cgi?query=mtree&sektion=8>`_
to hack in support for filesystem metadata tracking.

Arch supports nested repositories, darcs does not
-------------------------------------------------

Arch makes it possible to build a repository that contains other,
unrelated, repositories. This is useful when performing integration
tasks from separate sources.

Related Pages
=============

Blog Entries on Arch vs. Darcs
------------------------------


-  `Hynek's scribbles, August 02, 2004 <http://blog.ox.cx/2004/08/02/gnu_arch_vs_darcs/>`_
-  `Finding Lisp, January 28, 2005 <http://www.findinglisp.com/blog/2005/01/moving-to-darcs-side.html>`_

Arch vs. Darcs Mailing List Discussions
---------------------------------------


-  `David Roundy describes a case where Arch would silently fail <http://www.red-bean.com/pipermail/changesets/2003-April/000279.html>`_
   while patching, when darcs does the right thing. Tom Lord and
   others respond, discussing various trade-offs between the designs
   of Arch and darcs.

Credit
======

The original items here were inspired by Martin Pool's
`What's wrong with Arch <http://sourcefrog.net/weblog/software/vc/arch/whats-wrong.html>`_