mercurial_path_pattern 0.9.0

Mercurial Path Pattern Extension

Don’t repeat yourself defining [paths] over many repositories, specify the general rule once in ~/.hgrc.

path_pattern is a Mercurial extension used to define default remote path aliases. You may find it helpful if you maintain consistently layed out repository trees on a few machines.

It also provides shortcut hg cloneto «path-alias» (clone to address to which given path alias resolves).

Using path patterns

Install the extension (sudo pip install mercurial_path_pattern or manually in the way described below).

Write in your ~/.hgrc:

[extensions]
path_pattern =

[path_pattern]
lagrange.local = ~/devel/{repo}
lagrange.remote =  ssh://[e-mail]/sources/{repo}
bbssh.local = ~/devel/public/{below}
bbssh.remote = ssh://[e-mail]/Johny/{below:/=-}

Imagine ~/devel/personal/blog/drafts and ~/devel/public/pymods/acme are both some mercurial repositories. Then:

cd ~/devel/personal/blog/drafts
hg push lagrange
# Works, pushes to ssh://[e-mail]/sources/personal/blog/drafts

cd ~/devel/public/pymods/acme
hg pull lagrange
# Works, pulls from ssh://[e-mail]/sources/public/pymods/acme
hg pull bbssh
# Works too, pulls from ssh://[e-mail]/Johny/pymods-acme

Note: paths lagrange and bbssh need not be defined in any of those repositories (those repos may even lack .hg/hgrc at all).

For two repositories that’s not very useful, but once you have hundred of them, managing individual .hg/hgrc becomes a hassle (imagine changing lagrange.mekk.net to lagrange.mekk.com everywhere, or maybe adding second remote alias for the new development machine).

By default path patterns have lower priority than per-repository paths, so in case you define lagrange path on repository level, it won’t be overwritten. You can augment it by adding .enforce:

[path_pattern]
lagrange.local = ~/devel/{repo}
lagrange.remote =  ssh://[e-mail]/sources/{repo}
lagrange.enforce = true

With such config pattern wins against any path from .hg/hgrc (usually it is not recommended but can be handy if you have some broken paths scattered around repositories).

Using cloneto

There is also:

hg cloneto lagrange
# Equivalent to
#   hg clone . ssh://[e-mail]/sources/pymodules/acme
# but noticeably shorter

which works both for normal paths and paths derived from patterns, but is especially handy with patterns. In particular, it makes it possible to push newly created repository, for example:

cd ~/devel/libs
hg init xyz
cd xyz
hg cloneto lagrange
# Works, creates soures/libs/xyz on [e-mail]

Commands

Extension mostly works behind the courtains, making standard commands like hg pull, hg push, and hg incoming aware of extra paths. In particular, hg paths includes generated paths and can be used to check whether they are correct.

You may also use:

hg list_path_patterns

to check which patterns you configured.

The:

hg cloneto «alias»

command looks up alias among paths (both pattern-based, and normal) and issues clone to this path. It is equivalent to hg clone . «alias expansion»). In case alias is not defined, it fails.

Pattern syntax

Patterns are defined in [path_pattern] section of mercurial configuration file (typically they are kept in ~/.hgrc, but feel free to define them system-wide).

You may have as many patterns as you like. Example:

[path_pattern]
lagrange.local = ~/devel/{repo}
lagrange.remote =  ssh://[e-mail]/sources/{repo}
euler.local = ~/devel/{repo}
euler.remote =  ssh://[e-mail]/devel/{repo:/=.}/hg
wrk.local = ~/work/{what}
wrk.remote =  https://[e-mail]/{what:/=__:\=__}
ugly.local = ~/(topic)/sources/{subpath}/repo
ugly.remote = ssh://hg{topic}@devel.local/{topic}/{subpath}
cfg.local = ~/.config/upstart
cfg.remote = ssh://[e-mail]/configs/riemann/upstart

Every pattern is defined by the pair of keys - «alias».local and «alias».remote.

While processing patterns, the extension matches current repository root path against local pattern, and if it matches, extracts parts marked with markers and fills remote part with them to calculate proper path to use.

Local part specifies the format some repository path must have to match the rule. It should be absolute, but ~ and ~user are allowed. Some part(s) of the path may be replaced with {brace} or (paren) markers (both serve the same purpose, but {brace} matches everything aggressively while (paren) is limited to single path item and does not cross / or \\ characters). Those parts will be extracted from local repository path and available for use in alias being defined. Typically there will be single {marker} on the end, but more obscure patterns are possible (as ugly above illustrates). Markers are optional, if not used, rule applies to exactly one repository (see cfg above).

Remote part defines appropriate remote address. This is typical Mercurial remote path, where {marker}’s can be used to refer to values extracted from local path ({sth} is replaced with whatever matched {sth} or (sth) used in local path). Simple substitutions are allowed – {sth:x=y} means take whatever was extracted as sth and replace any x with y – and can be chained if necessary – {sth:x=y,v=z} means take whatever was extracted as sth, replace any x with y, then replace any v with z, then use the final result.

For example, with definitions above, if you happen to issue hg paths in repository ~/devel/python/libs/webby, the extension will:

1. Find that lagrange.local matches and that {repo} is python/libs/webby. Filling lagrange.remote with that value generates ssh://[e-mail]/sources/python/libs/webby, so finally it will create path alias lagrange=ssh://[e-mail]/sources/python/libs/webby;

2. Discover that euler.local also matches, and {repo} is again python/libs/webby. After replacing /-s with .-s, that brings alias euler=ssh://[e-mail]/devel/python.libs.webby/hg;

3. Ignore remaining patterns as they do not match.

Installation

Recommended way:

pip install mercurial_path_pattern

(prepend with sudo if necessary).

Manual way:

• install mercurial_extension_utils

• download path_pattern.py from this repository and save it somewhere

• activate extension by:

  path_pattern = /path/to/path_pattern.py

History

See HISTORY.txt

Development, bug reports, enhancement suggestions

Development is tracked on BitBucket, see http://bitbucket.org/Mekk/mercurial-path_pattern/

Use BitBucket issue tracker for bug reports and enhancement suggestions.

Additional notes

Information about this extension is also available on Mercurial Wiki: http://mercurial.selenic.com/wiki/PathPatternExtension