view mercurial/minifileset.py @ 38456:1cac2e8c7624

scmutil: move construction of instability count message to separate fn

When the commad we are running, introduces new instabilities, we show a message
like `5 new orphan changesets`, `2 new content-divergent changesets`, `1 new
phase-divergent changesets` etc which is very nice.

Now taking a step ahead, we want users to show how to fix them too. Something
like:

`5 new orphan changesets (run 'hg evolve' to resolve/stabilize them)`
`2 new content-divergent changesets (run 'hg evolve --content-divergent' to
resolve them)`

and maybe telling user a way to understand more about those new instabilities
like `hg evolve --list` or `hg log -r 'orphan()'` something like that.

The idea came from issue5855 which I want to fix because fixing that will result
in a nice UI.

Taking the construction logic out will allow extensions like evolve (maybe
rebase too) to wrap that and add information about how to resolve and how to
understand the instability more.

Differential Revision: https://phab.mercurial-scm.org/D3734

# minifileset.py - a simple language to select files
#
# Copyright 2017 Facebook, Inc.
#
# 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

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

def _compile(tree):
    if not tree:
        raise error.ParseError(_("missing argument"))
    op = tree[0]
    if op in {'symbol', 'string', 'kindpat'}:
        name = fileset.getpattern(tree, {'path'}, _('invalid file pattern'))
        if name.startswith('**'): # file extension test, ex. "**.tar.gz"
            ext = name[2:]
            for c in pycompat.bytestr(ext):
                if c in '*{}[]?/\\':
                    raise error.ParseError(_('reserved character: %s') % c)
            return lambda n, s: n.endswith(ext)
        elif name.startswith('path:'): # directory or full path test
            p = name[5:] # prefix
            pl = len(p)
            f = lambda n, s: n.startswith(p) and (len(n) == pl
                                                  or n[pl:pl + 1] == '/')
            return f
        raise error.ParseError(_("unsupported file pattern: %s") % name,
                               hint=_('paths must be prefixed with "path:"'))
    elif op == 'or':
        func1 = _compile(tree[1])
        func2 = _compile(tree[2])
        return lambda n, s: func1(n, s) or func2(n, s)
    elif op == 'and':
        func1 = _compile(tree[1])
        func2 = _compile(tree[2])
        return lambda n, s: func1(n, s) and func2(n, s)
    elif op == 'not':
        return lambda n, s: not _compile(tree[1])(n, s)
    elif op == 'group':
        return _compile(tree[1])
    elif op == 'func':
        symbols = {
            'all': lambda n, s: True,
            'none': lambda n, s: False,
            'size': lambda n, s: fileset.sizematcher(tree[2])(s),
        }

        name = fileset.getsymbol(tree[1])
        if name in symbols:
            return symbols[name]

        raise error.UnknownIdentifier(name, symbols.keys())
    elif op == 'minus':     # equivalent to 'x and not y'
        func1 = _compile(tree[1])
        func2 = _compile(tree[2])
        return lambda n, s: func1(n, s) and not func2(n, s)
    elif op == 'negate':
        raise error.ParseError(_("can't use negate operator in this context"))
    elif op == 'list':
        raise error.ParseError(_("can't use a list in this context"),
                               hint=_('see hg help "filesets.x or y"'))
    raise error.ProgrammingError('illegal tree: %r' % (tree,))

def compile(text):
    """generate a function (path, size) -> bool from filter specification.

    "text" could contain the operators defined by the fileset language for
    common logic operations, and parenthesis for grouping.  The supported path
    tests are '**.extname' for file extension test, and '"path:dir/subdir"'
    for prefix test.  The ``size()`` predicate is borrowed from filesets to test
    file size.  The predicates ``all()`` and ``none()`` are also supported.

    '(**.php & size(">10MB")) | **.zip | (path:bin & !path:bin/README)' for
    example, will catch all php files whose size is greater than 10 MB, all
    files whose name ends with ".zip", and all files under "bin" in the repo
    root except for "bin/README".
    """
    tree = fileset.parse(text)
    return _compile(tree)