comparison mercurial/match.py @ 33379:7ddb2aa2b7af

match: express anypats(), not prefix(), in terms of the others

When I added prefix() in 9789b4a7c595 (match: introduce boolean
prefix() method, 2014-10-28), we already had always(), isexact(), and
anypats(), so it made sense to write it in terms of them (a prefix
matcher is one that isn't any of the other types). It's only now that
I realize that it's much more natural to define prefix() explicitly
(it's one that uses path: patterns, roughly speaking) and let
anypats() be defined in terms of the others. Remember that these
methods are all used for determining which fast paths are
possible. anypats() simply means that no fast paths are possible (it
could be called complex() instead). Further evidence is that
rootfilesin:some/dir does not have any patterns, but it's still
considered to be an anypats() matcher. That's because anypats() really
just means that it's not a prefix() matcher (and not always() and not
isexact()).

This patch thus changes prefix() to return False by default and
anypats() to return True only if the other three are False. Having
anypats() be True by default also seems like a good thing, because it
means forgetting to override it will lead only to performance bugs,
not correctness bugs.

Since the base class's implementation changes, we're also forced to
update the subclasses. That change exposed and fixed a bug in the
differencematcher: for example when both its two input matchers were
prefix matchers, we would say that the result was also a prefix
matcher, which is incorrect, because e.g "path:dir - path:dir/foo" no
longer matches everything under "dir" (which is what prefix() means).

33378:adf95bfb423a

        This function's behavior is undefined if it has returned False for
        one of the dir's parent directories.
        '''
        return False

    def anypats(self):
        '''Matcher uses patterns or include/exclude.'''
        return False

    def always(self):
        '''Matcher will match everything and .files() will be empty
        - optimization might be possible and necessary.'''
        return False

    def isexact(self):
        return False

    def prefix(self):
        return not self.always() and not self.isexact() and not self.anypats()

class alwaysmatcher(basematcher):
    '''Matches everything.'''

    def __init__(self, root, cwd, badfn=None, relativeuipath=False):

                dir in self._fileset or
                dir in self._dirs or
                any(parentdir in self._fileset
                    for parentdir in util.finddirs(dir)))

    def anypats(self):
        return self._anypats

    def __repr__(self):
        return ('<patternmatcher patterns=%r>' % self._pats)

class includematcher(basematcher):

        return ('.' in self._roots or
                dir in self._roots or
                dir in self._dirs or
                any(parentdir in self._roots
                    for parentdir in util.finddirs(dir)))

    def anypats(self):
        return True

    def __repr__(self):
        return ('<includematcher includes=%r>' % self._pats)

class exactmatcher(basematcher):

            return False
        return bool(self._m1.visitdir(dir))

    def isexact(self):
        return self._m1.isexact()

    def anypats(self):
        return self._m1.anypats() or self._m2.anypats()

    def __repr__(self):
        return ('<differencematcher m1=%r, m2=%r>' % (self._m1, self._m2))

def intersectmatchers(m1, m2):

    def always(self):
        return self._m1.always() and self._m2.always()

    def isexact(self):
        return self._m1.isexact() or self._m2.isexact()

    def anypats(self):
        return self._m1.anypats() or self._m2.anypats()

    def __repr__(self):
        return ('<intersectionmatcher m1=%r, m2=%r>' % (self._m1, self._m2))

class subdirmatcher(basematcher):

        return self._matcher.visitdir(dir)

    def always(self):
        return self._always

    def anypats(self):
        return self._matcher.anypats()

    def __repr__(self):
        return ('<subdirmatcher path=%r, matcher=%r>' %
                (self._path, self._matcher))

        self._includes = includes

    def __call__(self, value):
        return value in self._includes or self._matcher(value)

    def anypats(self):
        return True

    def prefix(self):
        return False

    def __repr__(self):
        return ('<forceincludematcher matcher=%r, includes=%r>' %
                (self._matcher, sorted(self._includes)))

class unionmatcher(basematcher):

        for match in self._matchers:
            if match(value):
                return True
        return False

    def anypats(self):
        return True

    def prefix(self):
        return False

    def __repr__(self):
        return ('<unionmatcher matchers=%r>' % self._matchers)

class negatematcher(basematcher):
    def __init__(self, matcher):
        self._matcher = matcher

    def __call__(self, value):
        return not self._matcher(value)

    def anypats(self):
        return True

    def __repr__(self):
        return ('<negatematcher matcher=%r>' % self._matcher)

def patkind(pattern, default=None):

33379:7ddb2aa2b7af

        This function's behavior is undefined if it has returned False for
        one of the dir's parent directories.
        '''
        return False

    def always(self):
        '''Matcher will match everything and .files() will be empty --
        optimization might be possible.'''
        return False

    def isexact(self):
        '''Matcher will match exactly the list of files in .files() --
        optimization might be possible.'''
        return False

    def prefix(self):
        '''Matcher will match the paths in .files() recursively --
        optimization might be possible.'''
        return False

    def anypats(self):
        '''None of .always(), .isexact(), and .prefix() is true --
        optimizations will be difficult.'''
        return not self.always() and not self.isexact() and not self.prefix()

class alwaysmatcher(basematcher):
    '''Matches everything.'''

    def __init__(self, root, cwd, badfn=None, relativeuipath=False):

                dir in self._fileset or
                dir in self._dirs or
                any(parentdir in self._fileset
                    for parentdir in util.finddirs(dir)))

    def prefix(self):
        return not self._anypats

    def __repr__(self):
        return ('<patternmatcher patterns=%r>' % self._pats)

class includematcher(basematcher):

        return ('.' in self._roots or
                dir in self._roots or
                dir in self._dirs or
                any(parentdir in self._roots
                    for parentdir in util.finddirs(dir)))

    def __repr__(self):
        return ('<includematcher includes=%r>' % self._pats)

class exactmatcher(basematcher):

            return False
        return bool(self._m1.visitdir(dir))

    def isexact(self):
        return self._m1.isexact()

    def __repr__(self):
        return ('<differencematcher m1=%r, m2=%r>' % (self._m1, self._m2))

def intersectmatchers(m1, m2):

    def always(self):
        return self._m1.always() and self._m2.always()

    def isexact(self):
        return self._m1.isexact() or self._m2.isexact()

    def __repr__(self):
        return ('<intersectionmatcher m1=%r, m2=%r>' % (self._m1, self._m2))

class subdirmatcher(basematcher):

        return self._matcher.visitdir(dir)

    def always(self):
        return self._always

    def prefix(self):
        return self._matcher.prefix() and not self._always

    def __repr__(self):
        return ('<subdirmatcher path=%r, matcher=%r>' %
                (self._path, self._matcher))

        self._includes = includes

    def __call__(self, value):
        return value in self._includes or self._matcher(value)

    def __repr__(self):
        return ('<forceincludematcher matcher=%r, includes=%r>' %
                (self._matcher, sorted(self._includes)))

class unionmatcher(basematcher):

        for match in self._matchers:
            if match(value):
                return True
        return False

    def __repr__(self):
        return ('<unionmatcher matchers=%r>' % self._matchers)

class negatematcher(basematcher):
    def __init__(self, matcher):
        self._matcher = matcher

    def __call__(self, value):
        return not self._matcher(value)

    def __repr__(self):
        return ('<negatematcher matcher=%r>' % self._matcher)

def patkind(pattern, default=None):