Specifying Revisions
""""""""""""""""""""

    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:
    
    ``adds(pattern)``
      Changesets that add a file matching pattern.
      
      The pattern without explicit kind like ``glob:`` is expected to be
      relative to the current directory and match against a file or a
      directory.
    
    ``all()``
      All changesets, the same as ``0:tip``.
    
    ``ancestor(*changeset)``
      A greatest common ancestor of the changesets.
      
      Accepts 0 or more changesets.
      Will return empty list when passed no args.
      Greatest common ancestor of a single changeset is that changeset.
    
    ``ancestors(set[, depth])``
      Changesets that are ancestors of changesets in set, including the
      given changesets themselves.
      
      If depth is specified, the result only includes changesets up to
      the specified generation.
    
    ``author(string)``
      Alias for ``user(string)``.
    
    ``bisect(string)``
      Changesets marked in the specified bisect status:
      
      - ``good``, ``bad``, ``skip``: csets explicitly marked as good/bad/skip
      - ``goods``, ``bads``      : csets topologically good/bad
      - ``range``              : csets taking part in the bisection
      - ``pruned``             : csets that are goods, bads or skipped
      - ``untested``           : csets whose fate is yet unknown
      - ``ignored``            : csets ignored due to DAG topology
      - ``current``            : the cset currently being bisected
    
    ``bookmark([name])``
      The named bookmark or all bookmarks.
      
      Pattern matching is supported for `name`. See :hg:`help revisions.patterns`.
    
    ``branch(string or set)``
      All changesets belonging to the given branch or the branches of the given
      changesets.
      
      Pattern matching is supported for `string`. See
      :hg:`help revisions.patterns`.
    
    ``branchpoint()``
      Changesets with more than one child.
    
    ``bundle()``
      Changesets in the bundle.
      
      Bundle must be specified by the -R option.
    
    ``children(set)``
      Child changesets of changesets in set.
    
    ``closed()``
      Changeset is closed.
    
    ``contains(pattern)``
      The revision's manifest contains a file matching pattern (but might not
      modify it). See :hg:`help patterns` for information about file patterns.
      
      The pattern without explicit kind like ``glob:`` is expected to be
      relative to the current directory and match against a file exactly
      for efficiency.
    
    ``contentdivergent()``
      Final successors of changesets with an alternative set of final
      successors. (EXPERIMENTAL)
    
    ``converted([id])``
      Changesets converted from the given identifier in the old repository if
      present, or all converted changesets if no identifier is specified.
    
    ``date(interval)``
      Changesets within the interval, see :hg:`help dates`.
    
    ``desc(string)``
      Search commit message for string. The match is case-insensitive.
      
      Pattern matching is supported for `string`. See
      :hg:`help revisions.patterns`.
    
    ``descendants(set[, depth])``
      Changesets which are descendants of changesets in set, including the
      given changesets themselves.
      
      If depth is specified, the result only includes changesets up to
      the specified generation.
    
    ``destination([set])``
      Changesets that were created by a graft, transplant or rebase operation,
      with the given revisions specified as the source.  Omitting the optional set
      is the same as passing all().
    
    ``draft()``
      Changeset in draft phase.
    
    ``extdata(source)``
      Changesets in the specified extdata source. (EXPERIMENTAL)
    
    ``extinct()``
      Obsolete changesets with obsolete descendants only.
    
    ``extra(label, [value])``
      Changesets with the given label in the extra metadata, with the given
      optional value.
      
      Pattern matching is supported for `value`. See
      :hg:`help revisions.patterns`.
    
    ``file(pattern)``
      Changesets affecting files matched by pattern.
      
      For a faster but less accurate result, consider using ``filelog()``
      instead.
      
      This predicate uses ``glob:`` as the default kind of pattern.
    
    ``filelog(pattern)``
      Changesets connected to the specified filelog.
      
      For performance reasons, visits only revisions mentioned in the file-level
      filelog, rather than filtering through all changesets (much faster, but
      doesn't include deletes or duplicate changes). For a slower, more accurate
      result, use ``file()``.
      
      The pattern without explicit kind like ``glob:`` is expected to be
      relative to the current directory and match against a file exactly
      for efficiency.
      
      If some linkrev points to revisions filtered by the current repoview, we'll
      work around it to return a non-filtered value.
    
    ``first(set, [n])``
      An alias for limit().
    
    ``follow([pattern[, startrev]])``
      An alias for ``::.`` (ancestors of the working directory's first parent).
      If pattern is specified, the histories of files matching given
      pattern in the revision given by startrev are followed, including copies.
    
    ``followlines(file, fromline:toline[, startrev=., descend=False])``
      Changesets modifying `file` in line range ('fromline', 'toline').
      
      Line range corresponds to 'file' content at 'startrev' and should hence be
      consistent with file size. If startrev is not specified, working directory's
      parent is used.
      
      By default, ancestors of 'startrev' are returned. If 'descend' is True,
      descendants of 'startrev' are returned though renames are (currently) not
      followed in this direction.
    
    ``grep(regex)``
      Like ``keyword(string)`` but accepts a regex. Use ``grep(r'...')``
      to ensure special escape characters are handled correctly. Unlike
      ``keyword(string)``, the match is case-sensitive.
    
    ``head()``
      Changeset is a named branch head.
    
    ``heads(set)``
      Members of set with no children in set.
    
    ``hidden()``
      Hidden changesets.
    
    ``id(string)``
      Revision non-ambiguously specified by the given hex string prefix.
    
    ``keyword(string)``
      Search commit message, user name, and names of changed files for
      string. The match is case-insensitive.
      
      For a regular expression or case sensitive search of these fields, use
      ``grep(regex)``.
    
    ``last(set, [n])``
      Last n members of set, defaulting to 1.
    
    ``limit(set[, n[, offset]])``
      First n members of set, defaulting to 1, starting from offset.
    
    ``matching(revision [, field])``
      Changesets in which a given set of fields match the set of fields in the
      selected revision or set.
      
      To match more than one field pass the list of fields to match separated
      by spaces (e.g. ``author description``).
      
      Valid fields are most regular revision fields and some special fields.
      
      Regular revision fields are ``description``, ``author``, ``branch``,
      ``date``, ``files``, ``phase``, ``parents``, ``substate``, ``user``
      and ``diff``.
      Note that ``author`` and ``user`` are synonyms. ``diff`` refers to the
      contents of the revision. Two revisions matching their ``diff`` will
      also match their ``files``.
      
      Special fields are ``summary`` and ``metadata``:
      ``summary`` matches the first line of the description.
      ``metadata`` is equivalent to matching ``description user date``
      (i.e. it matches the main metadata fields).
      
      ``metadata`` is the default field which is used when no fields are
      specified. You can match more than one field at a time.
    
    ``max(set)``
      Changeset with highest revision number in set.
    
    ``merge()``
      Changeset is a merge changeset.
    
    ``min(set)``
      Changeset with lowest revision number in set.
    
    ``modifies(pattern)``
      Changesets modifying files matched by pattern.
      
      The pattern without explicit kind like ``glob:`` is expected to be
      relative to the current directory and match against a file or a
      directory.
    
    ``named(namespace)``
      The changesets in a given namespace.
      
      Pattern matching is supported for `namespace`. See
      :hg:`help revisions.patterns`.
    
    ``obsolete()``
      Mutable changeset with a newer version.
    
    ``only(set, [set])``
      Changesets that are ancestors of the first set that are not ancestors
      of any other head in the repo. If a second set is specified, the result
      is ancestors of the first set that are not ancestors of the second set
      (i.e. ::<set1> - ::<set2>).
    
    ``origin([set])``
      Changesets that were specified as a source for the grafts, transplants or
      rebases that created the given revisions.  Omitting the optional set is the
      same as passing all().  If a changeset created by these operations is itself
      specified as a source for one of these operations, only the source changeset
      for the first operation is selected.
    
    ``orphan()``
      Non-obsolete changesets with obsolete ancestors. (EXPERIMENTAL)
    
    ``outgoing([path])``
      Changesets not found in the specified destination repository, or the
      default push location.
    
    ``p1([set])``
      First parent of changesets in set, or the working directory.
    
    ``p2([set])``
      Second parent of changesets in set, or the working directory.
    
    ``parents([set])``
      The set of all parents for all changesets in set, or the working directory.
    
    ``phasedivergent()``
      Mutable changesets marked as successors of public changesets.
      
      Only non-public and non-obsolete changesets can be `phasedivergent`.
      (EXPERIMENTAL)
    
    ``present(set)``
      An empty set, if any revision in set isn't found; otherwise,
      all revisions in set.
      
      If any of specified revisions is not present in the local repository,
      the query is normally aborted. But this predicate allows the query
      to continue even in such cases.
    
    ``public()``
      Changeset in public phase.
    
    ``remote([id [,path]])``
      Local revision that corresponds to the given identifier in a
      remote repository, if present. Here, the '.' identifier is a
      synonym for the current local branch.
    
    ``removes(pattern)``
      Changesets which remove files matching pattern.
      
      The pattern without explicit kind like ``glob:`` is expected to be
      relative to the current directory and match against a file or a
      directory.
    
    ``rev(number)``
      Revision with the given numeric identifier.
    
    ``reverse(set)``
      Reverse order of set.
    
    ``roots(set)``
      Changesets in set with no parent changeset in set.
    
    ``secret()``
      Changeset in secret phase.
    
    ``sort(set[, [-]key... [, ...]])``
      Sort set by keys. The default sort order is ascending, specify a key
      as ``-key`` to sort in descending order.
      
      The keys can be:
      
      - ``rev`` for the revision number,
      - ``branch`` for the branch name,
      - ``desc`` for the commit message (description),
      - ``user`` for user name (``author`` can be used as an alias),
      - ``date`` for the commit date
      - ``topo`` for a reverse topographical sort
      
      The ``topo`` sort order cannot be combined with other sort keys. This sort
      takes one optional argument, ``topo.firstbranch``, which takes a revset that
      specifies what topographical branches to prioritize in the sort.
    
    ``subrepo([pattern])``
      Changesets that add, modify or remove the given subrepo.  If no subrepo
      pattern is named, any subrepo changes are returned.
    
    ``successors(set)``
      All successors for set, including the given set themselves
    
    ``tag([name])``
      The specified tag by name, or all tagged revisions if no name is given.
      
      Pattern matching is supported for `name`. See
      :hg:`help revisions.patterns`.
    
    ``user(string)``
      User name contains string. The match is case-insensitive.
      
      Pattern matching is supported for `string`. See
      :hg:`help revisions.patterns`.
    
    ``wdir()``
      Working directory. (EXPERIMENTAL)
    
    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