view mercurial/fancyopts.py @ 35616:706aa203b396

fileset: add a lightweight file filtering language

This patch was inspired by one that Jun Wu authored for the fb-experimental
repo, to avoid using matcher for efficiency[1].  We want a way to specify what
files will be converted to LFS at commit time.  And per discussion, we also want
to specify what files to skip, text diff, or merge in another config option.
The current `lfs.threshold` config option could not satisfy complex needs.  I'm
putting it in a core package because Augie floated the idea of also using it for
narrow and sparse.

Yuya suggested farming out to fileset.parse(), which added support for more
symbols.  The only fileset element not supported here is 'negate'.  (List isn't
supported by filesets either.)  I also changed the 'always' token to the 'all()'
predicate for consistency, and introduced 'none()' to improve readability in a
future tracked file based config.  The extension operator was changed from '.'
to '**', to match how recursive path globs are specified.  Finally, I changed
the path matcher from '/' to 'path:' at Yuya's suggestion, for consistency with
matcher.  Unfortunately, ':' is currently reserved in filesets, so this has to
be quoted to be processed as a string instead of a symbol[2].  We should
probably revisit that, because it's seriously ugly.  But it's only used by an
experimental extension, and I think using a file based config for LFS may drive
some more tweaks, so I'm settling for this for now.

I reserved all of the glob characters in fileset except '.' and '_' for the
extension test because those are likely valid extension characters.

Sample filter settings:

  all()                        # everything
  size(">20MB")                # larger than 20MB
  !**.txt                      # except for .txt files
  **.zip | **.tar.gz | **.7z   # some types of compressed files
  "path:bin"                   # files under "bin" in the project root

[1] https://www.mercurial-scm.org/pipermail/mercurial-devel/2017-December/109387.html
[2] https://www.mercurial-scm.org/pipermail/mercurial-devel/2018-January/109729.html

# fancyopts.py - better command line parsing
#
#  Copyright 2005-2009 Matt Mackall <[e-mail]> and others
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import absolute_import

import functools

from .i18n import _
from . import (
    error,
    pycompat,
)

# Set of flags to not apply boolean negation logic on
nevernegate = {
    # avoid --no-noninteractive
    'noninteractive',
    # These two flags are special because they cause hg to do one
    # thing and then exit, and so aren't suitable for use in things
    # like aliases anyway.
    'help',
    'version',
}

def _earlyoptarg(arg, shortlist, namelist):
    """Check if the given arg is a valid unabbreviated option

    Returns (flag_str, has_embedded_value?, embedded_value, takes_value?)

    >>> def opt(arg):
    ...     return _earlyoptarg(arg, b'R:q', [b'cwd=', b'debugger'])

    long form:

    >>> opt(b'--cwd')
    ('--cwd', False, '', True)
    >>> opt(b'--cwd=')
    ('--cwd', True, '', True)
    >>> opt(b'--cwd=foo')
    ('--cwd', True, 'foo', True)
    >>> opt(b'--debugger')
    ('--debugger', False, '', False)
    >>> opt(b'--debugger=')  # invalid but parsable
    ('--debugger', True, '', False)

    short form:

    >>> opt(b'-R')
    ('-R', False, '', True)
    >>> opt(b'-Rfoo')
    ('-R', True, 'foo', True)
    >>> opt(b'-q')
    ('-q', False, '', False)
    >>> opt(b'-qfoo')  # invalid but parsable
    ('-q', True, 'foo', False)

    unknown or invalid:

    >>> opt(b'--unknown')
    ('', False, '', False)
    >>> opt(b'-u')
    ('', False, '', False)
    >>> opt(b'-ufoo')
    ('', False, '', False)
    >>> opt(b'--')
    ('', False, '', False)
    >>> opt(b'-')
    ('', False, '', False)
    >>> opt(b'-:')
    ('', False, '', False)
    >>> opt(b'-:foo')
    ('', False, '', False)
    """
    if arg.startswith('--'):
        flag, eq, val = arg.partition('=')
        if flag[2:] in namelist:
            return flag, bool(eq), val, False
        if flag[2:] + '=' in namelist:
            return flag, bool(eq), val, True
    elif arg.startswith('-') and arg != '-' and not arg.startswith('-:'):
        flag, val = arg[:2], arg[2:]
        i = shortlist.find(flag[1:])
        if i >= 0:
            return flag, bool(val), val, shortlist.startswith(':', i + 1)
    return '', False, '', False

def earlygetopt(args, shortlist, namelist, gnu=False, keepsep=False):
    """Parse options like getopt, but ignores unknown options and abbreviated
    forms

    If gnu=False, this stops processing options as soon as a non/unknown-option
    argument is encountered. Otherwise, option and non-option arguments may be
    intermixed, and unknown-option arguments are taken as non-option.

    If keepsep=True, '--' won't be removed from the list of arguments left.
    This is useful for stripping early options from a full command arguments.

    >>> def get(args, gnu=False, keepsep=False):
    ...     return earlygetopt(args, b'R:q', [b'cwd=', b'debugger'],
    ...                        gnu=gnu, keepsep=keepsep)

    default parsing rules for early options:

    >>> get([b'x', b'--cwd', b'foo', b'-Rbar', b'-q', b'y'], gnu=True)
    ([('--cwd', 'foo'), ('-R', 'bar'), ('-q', '')], ['x', 'y'])
    >>> get([b'x', b'--cwd=foo', b'y', b'-R', b'bar', b'--debugger'], gnu=True)
    ([('--cwd', 'foo'), ('-R', 'bar'), ('--debugger', '')], ['x', 'y'])
    >>> get([b'--unknown', b'--cwd=foo', b'--', '--debugger'], gnu=True)
    ([('--cwd', 'foo')], ['--unknown', '--debugger'])

    restricted parsing rules (early options must come first):

    >>> get([b'--cwd', b'foo', b'-Rbar', b'x', b'-q', b'y'], gnu=False)
    ([('--cwd', 'foo'), ('-R', 'bar')], ['x', '-q', 'y'])
    >>> get([b'--cwd=foo', b'x', b'y', b'-R', b'bar', b'--debugger'], gnu=False)
    ([('--cwd', 'foo')], ['x', 'y', '-R', 'bar', '--debugger'])
    >>> get([b'--unknown', b'--cwd=foo', b'--', '--debugger'], gnu=False)
    ([], ['--unknown', '--cwd=foo', '--', '--debugger'])

    stripping early options (without loosing '--'):

    >>> get([b'x', b'-Rbar', b'--', '--debugger'], gnu=True, keepsep=True)[1]
    ['x', '--', '--debugger']

    last argument:

    >>> get([b'--cwd'])
    ([], ['--cwd'])
    >>> get([b'--cwd=foo'])
    ([('--cwd', 'foo')], [])
    >>> get([b'-R'])
    ([], ['-R'])
    >>> get([b'-Rbar'])
    ([('-R', 'bar')], [])
    >>> get([b'-q'])
    ([('-q', '')], [])
    >>> get([b'-q', b'--'])
    ([('-q', '')], [])

    '--' may be a value:

    >>> get([b'-R', b'--', b'x'])
    ([('-R', '--')], ['x'])
    >>> get([b'--cwd', b'--', b'x'])
    ([('--cwd', '--')], ['x'])

    value passed to bool options:

    >>> get([b'--debugger=foo', b'x'])
    ([], ['--debugger=foo', 'x'])
    >>> get([b'-qfoo', b'x'])
    ([], ['-qfoo', 'x'])

    short option isn't separated with '=':

    >>> get([b'-R=bar'])
    ([('-R', '=bar')], [])

    ':' may be in shortlist, but shouldn't be taken as an option letter:

    >>> get([b'-:', b'y'])
    ([], ['-:', 'y'])

    '-' is a valid non-option argument:

    >>> get([b'-', b'y'])
    ([], ['-', 'y'])
    """
    parsedopts = []
    parsedargs = []
    pos = 0
    while pos < len(args):
        arg = args[pos]
        if arg == '--':
            pos += not keepsep
            break
        flag, hasval, val, takeval = _earlyoptarg(arg, shortlist, namelist)
        if not hasval and takeval and pos + 1 >= len(args):
            # missing last argument
            break
        if not flag or hasval and not takeval:
            # non-option argument or -b/--bool=INVALID_VALUE
            if gnu:
                parsedargs.append(arg)
                pos += 1
            else:
                break
        elif hasval == takeval:
            # -b/--bool or -s/--str=VALUE
            parsedopts.append((flag, val))
            pos += 1
        else:
            # -s/--str VALUE
            parsedopts.append((flag, args[pos + 1]))
            pos += 2

    parsedargs.extend(args[pos:])
    return parsedopts, parsedargs

def fancyopts(args, options, state, gnu=False, early=False, optaliases=None):
    """
    read args, parse options, and store options in state

    each option is a tuple of:

      short option or ''
      long option
      default value
      description
      option value label(optional)

    option types include:

      boolean or none - option sets variable in state to true
      string - parameter string is stored in state
      list - parameter string is added to a list
      integer - parameter strings is stored as int
      function - call function with parameter

    optaliases is a mapping from a canonical option name to a list of
    additional long options. This exists for preserving backward compatibility
    of early options. If we want to use it extensively, please consider moving
    the functionality to the options table (e.g separate long options by '|'.)

    non-option args are returned
    """
    if optaliases is None:
        optaliases = {}
    namelist = []
    shortlist = ''
    argmap = {}
    defmap = {}
    negations = {}
    alllong = set(o[1] for o in options)

    for option in options:
        if len(option) == 5:
            short, name, default, comment, dummy = option
        else:
            short, name, default, comment = option
        # convert opts to getopt format
        onames = [name]
        onames.extend(optaliases.get(name, []))
        name = name.replace('-', '_')

        argmap['-' + short] = name
        for n in onames:
            argmap['--' + n] = name
        defmap[name] = default

        # copy defaults to state
        if isinstance(default, list):
            state[name] = default[:]
        elif callable(default):
            state[name] = None
        else:
            state[name] = default

        # does it take a parameter?
        if not (default is None or default is True or default is False):
            if short:
                short += ':'
            onames = [n + '=' for n in onames]
        elif name not in nevernegate:
            for n in onames:
                if n.startswith('no-'):
                    insert = n[3:]
                else:
                    insert = 'no-' + n
                # backout (as a practical example) has both --commit and
                # --no-commit options, so we don't want to allow the
                # negations of those flags.
                if insert not in alllong:
                    assert ('--' + n) not in negations
                    negations['--' + insert] = '--' + n
                    namelist.append(insert)
        if short:
            shortlist += short
        if name:
            namelist.extend(onames)

    # parse arguments
    if early:
        parse = functools.partial(earlygetopt, gnu=gnu)
    elif gnu:
        parse = pycompat.gnugetoptb
    else:
        parse = pycompat.getoptb
    opts, args = parse(args, shortlist, namelist)

    # transfer result to state
    for opt, val in opts:
        boolval = True
        negation = negations.get(opt, False)
        if negation:
            opt = negation
            boolval = False
        name = argmap[opt]
        obj = defmap[name]
        t = type(obj)
        if callable(obj):
            state[name] = defmap[name](val)
        elif t is type(1):
            try:
                state[name] = int(val)
            except ValueError:
                raise error.Abort(_('invalid value %r for option %s, '
                                   'expected int') % (val, opt))
        elif t is type(''):
            state[name] = val
        elif t is type([]):
            state[name].append(val)
        elif t is type(None) or t is type(False):
            state[name] = boolval

    # return unparsed args
    return args