view mercurial/help/patterns.txt @ 27279:40eb385f798f

tests: add test for Python 3 compatibility

Python 3 is inevitable. There have been incremental movements towards
converting the code base to be Python 3 compatible. Unfortunately, we
don't have any tests that look for Python 3 compatibility. This patch
changes that.

We introduce a check-py3-compat.py script whose role is to verify
Python 3 compatibility of the files passed in. We add a test that
calls this script with all .py files from the source checkout.

The script currently only verifies that absolute_import and
print_function are used. These are the low hanging fruits for Python
compatbility. Over time, we can include more checks, including
verifying we're able to load each Python file with Python 3. You
have to start somewhere.

Accepting this patch means that all new .py files must have
absolute_import and print_function (if "print" is used) to avoid
a new warning about Python 3 incompatibility. We've already
converted several files to use absolute_import and print_function
is in the same boat, so I don't think this is such a radical
proposition.

Mercurial accepts several notations for identifying one or more files
at a time.

By default, Mercurial treats filenames as shell-style extended glob
patterns.

Alternate pattern notations must be specified explicitly.

.. note::

  Patterns specified in ``.hgignore`` are not rooted.
  Please see :hg:`help hgignore` for details.

To use a plain path name without any pattern matching, start it with
``path:``. These path names must completely match starting at the
current repository root.

To use an extended glob, start a name with ``glob:``. Globs are rooted
at the current directory; a glob such as ``*.c`` will only match files
in the current directory ending with ``.c``.

The supported glob syntax extensions are ``**`` to match any string
across path separators and ``{a,b}`` to mean "a or b".

To use a Perl/Python regular expression, start a name with ``re:``.
Regexp pattern matching is anchored at the root of the repository.

To read name patterns from a file, use ``listfile:`` or ``listfile0:``.
The latter expects null delimited patterns while the former expects line
feeds. Each string read from the file is itself treated as a file
pattern.

To read a set of patterns from a file, use ``include:`` or ``subinclude:``.
``include:`` will use all the patterns from the given file and treat them as if
they had been passed in manually.  ``subinclude:`` will only apply the patterns
against files that are under the subinclude file's directory. See :hg:`help
hgignore` for details on the format of these files.

All patterns, except for ``glob:`` specified in command line (not for
``-I`` or ``-X`` options), can match also against directories: files
under matched directories are treated as matched.

Plain examples::

  path:foo/bar   a name bar in a directory named foo in the root
                 of the repository
  path:path:name a file or directory named "path:name"

Glob examples::

  glob:*.c       any name ending in ".c" in the current directory
  *.c            any name ending in ".c" in the current directory
  **.c           any name ending in ".c" in any subdirectory of the
                 current directory including itself.
  foo/*.c        any name ending in ".c" in the directory foo
  foo/**.c       any name ending in ".c" in any subdirectory of foo
                 including itself.

Regexp examples::

  re:.*\.c$      any name ending in ".c", anywhere in the repository

File examples::

  listfile:list.txt  read list from list.txt with one file pattern per line
  listfile0:list.txt read list from list.txt with null byte delimiters

See also :hg:`help filesets`.

Include examples::

  include:path/to/mypatternfile    reads patterns to be applied to all paths
  subinclude:path/to/subignorefile reads patterns specifically for paths in the
                                   subdirectory