Mercurial supports several ways to specify revisions.

Specifying single revisions

===========================

A plain integer is treated as a revision number. Negative integers are

treated as sequential offsets from the tip, with -1 denoting the tip,

-2 denoting the revision prior to the tip, and so forth.

A 40-digit hexadecimal string is treated as a unique revision identifier.

A hexadecimal string less than 40 characters long is treated as a

unique revision identifier and is referred to as a short-form

identifier. A short-form identifier is only valid if it is the prefix

of exactly one full-length identifier.

Any other string is treated as a bookmark, tag, or branch name. A

bookmark is a movable pointer to a revision. A tag is a permanent name

associated with a revision. A branch name denotes the tipmost open branch head

of that branch - or if they are all closed, the tipmost closed head of the

branch. Bookmark, tag, and branch names must not contain the ":" character.

The reserved name "tip" always identifies the most recent revision.

The reserved name "null" indicates the null revision. This is the

revision of an empty repository, and the parent of revision 0.

The reserved name "." indicates the working directory parent. If no

working directory is checked out, it is equivalent to null. If an

uncommitted merge is in progress, "." is the revision of the first

parent.

Finally, commands that expect a single revision (like ``hg update``) also

accept revsets (see below for details). When given a revset, they use the

last revision of the revset. A few commands accept two single revisions

(like ``hg diff``). When given a revset, they use the first and the last

revisions of the revset.

Specifying multiple revisions

=============================

Mercurial supports a functional language for selecting a set of

revisions. Expressions in this language are called revsets.

The language supports a number of predicates which are joined by infix

operators. Parenthesis can be used for grouping.

Identifiers such as branch names may need quoting with single or

double quotes if they contain characters like ``-`` or if they match

one of the predefined predicates.

Special characters can be used in quoted identifiers by escaping them,

e.g., ``\n`` is interpreted as a newline. To prevent them from being

interpreted, strings can be prefixed with ``r``, e.g. ``r'...'``.

Operators

=========

There is a single prefix operator:

``not x``

  Changesets not in x. Short form is ``! x``.

These are the supported infix operators:

``x::y``

  A DAG range, meaning all changesets that are descendants of x and

  ancestors of y, including x and y themselves. If the first endpoint

  is left out, this is equivalent to ``ancestors(y)``, if the second

  is left out it is equivalent to ``descendants(x)``.

  An alternative syntax is ``x..y``.

``x:y``

  All changesets with revision numbers between x and y, both

  inclusive. Either endpoint can be left out, they default to 0 and

  tip.

``x and y``

  The intersection of changesets in x and y. Short form is ``x & y``.

``x or y``

  The union of changesets in x and y. There are two alternative short

  forms: ``x | y`` and ``x + y``.

``x - y``

  Changesets in x but not in y.

``x % y``

  Changesets that are ancestors of x but not ancestors of y (i.e. ::x - ::y).

  This is shorthand notation for ``only(x, y)`` (see below). The second

  argument is optional and, if left out, is equivalent to ``only(x)``.

``x^n``

  The nth parent of x, n == 0, 1, or 2.

  For n == 0, x; for n == 1, the first parent of each changeset in x;

  for n == 2, the second parent of changeset in x.

``x~n``

  The nth first ancestor of x; ``x~0`` is x; ``x~3`` is ``x^^^``.

  For n < 0, the nth unambiguous descendent of x.

``x ## y``

  Concatenate strings and identifiers into one string.

  All other prefix, infix and postfix operators have lower priority than

  ``##``. For example, ``a1 ## a2~2`` is equivalent to ``(a1 ## a2)~2``.

  For example::

    [revsetalias]

    issue(a1) = grep(r'\bissue[ :]?' ## a1 ## r'\b|\bbug\(' ## a1 ## r'\)')

  ``issue(1234)`` is equivalent to

  ``grep(r'\bissue[ :]?1234\b|\bbug\(1234\)')``

  in this case. This matches against all of "issue 1234", "issue:1234",

  "issue1234" and "bug(1234)".

There is a single postfix operator:

``x^``

  Equivalent to ``x^1``, the first parent of each changeset in x.

Patterns

========

Where noted, predicates that perform string matching can accept a pattern

string. The pattern may be either a literal, or a regular expression. If the

pattern starts with ``re:``, the remainder of the pattern is treated as a

regular expression. Otherwise, it is treated as a literal. To match a pattern

that actually starts with ``re:``, use the prefix ``literal:``.

Matching is case-sensitive, unless otherwise noted.  To perform a case-

insensitive match on a case-sensitive predicate, use a regular expression,

prefixed with ``(?i)``.

For example, ``tag(r're:(?i)release')`` matches "release" or "RELEASE"

or "Release", etc.

Predicates

==========

The following predicates are supported:

.. predicatesmarker

Aliases

=======

New predicates (known as "aliases") can be defined, using any combination of

existing predicates or other aliases. An alias definition looks like::

  <alias> = <definition>

in the ``revsetalias`` section of a Mercurial configuration file. Arguments

of the form `a1`, `a2`, etc. are substituted from the alias into the

definition.

For example,

::

  [revsetalias]

  h = heads()

  d(s) = sort(s, date)

  rs(s, k) = reverse(sort(s, k))

defines three aliases, ``h``, ``d``, and ``rs``. ``rs(0:tip, author)`` is

exactly equivalent to ``reverse(sort(0:tip, author))``.

Equivalents

===========

Command line equivalents for :hg:`log`::

  -f    ->  ::.

  -d x  ->  date(x)

  -k x  ->  keyword(x)

  -m    ->  merge()

  -u x  ->  user(x)

  -b x  ->  branch(x)

  -P x  ->  !::x

  -l x  ->  limit(expr, x)

Examples

========

Some sample queries:

- Changesets on the default branch::

    hg log -r "branch(default)"

- Changesets on the default branch since tag 1.5 (excluding merges)::

    hg log -r "branch(default) and 1.5:: and not merge()"

- Open branch heads::

    hg log -r "head() and not closed()"

- Changesets between tags 1.3 and 1.5 mentioning "bug" that affect

  ``hgext/*``::

    hg log -r "1.3::1.5 and keyword(bug) and file('hgext/*')"

- Changesets committed in May 2008, sorted by user::

    hg log -r "sort(date('May 2008'), user)"

- Changesets mentioning "bug" or "issue" that are not in a tagged

  release::

    hg log -r "(keyword(bug) or keyword(issue)) and not ancestors(tag())"

- Update to the commit that bookmark @ is pointing to, without activating the

  bookmark (this works because the last revision of the revset is used)::

    hg update :@

- Show diff between tags 1.3 and 1.5 (this works because the first and the

  last revisions of the revset are used)::

    hg diff -r 1.3::1.5