view mercurial/help/extensions.txt @ 18894:ed46c2b98b0d

dicthelpers.diff: compare against default for missing values

This is not only a bit faster, but also aligns with callers' expectations
better since we can legitimately have manifestdict's _flags set to '' instead
of unset.

hg perfmergecalculate -r .
before: ! wall 0.139582 comb 0.140000 user 0.140000 sys 0.000000 (best of 59)
after:  ! wall 0.126154 comb 0.120000 user 0.120000 sys 0.000000 (best of 74)

hg perfmergecalculate -r .^
before: ! wall 0.236333 comb 0.240000 user 0.240000 sys 0.000000 (best of 36)
after:  ! wall 0.212265 comb 0.210000 user 0.210000 sys 0.000000 (best of 45)

Mercurial has the ability to add new features through the use of
extensions. Extensions may add new commands, add options to
existing commands, change the default behavior of commands, or
implement hooks.

Extensions are not loaded by default for a variety of reasons:
they can increase startup overhead; they may be meant for advanced
usage only; they may provide potentially dangerous abilities (such
as letting you destroy or modify history); they might not be ready
for prime time; or they may alter some usual behaviors of stock
Mercurial. It is thus up to the user to activate extensions as
needed.

To enable the "foo" extension, either shipped with Mercurial or in the
Python search path, create an entry for it in your configuration file,
like this::

  [extensions]
  foo =

You may also specify the full path to an extension::

  [extensions]
  myfeature = ~/.hgext/myfeature.py

To explicitly disable an extension enabled in a configuration file of
broader scope, prepend its path with !::

  [extensions]
  # disabling extension bar residing in /path/to/extension/bar.py
  bar = !/path/to/extension/bar.py
  # ditto, but no path was supplied for extension baz
  baz = !