def freeze(h, output_yaml, resolve, groups):
    """Output installed packages."""
    if not groups:
        groups = filter(lambda group: not group.lower().startswith("bower"),
                        h.requirements.keys())
    else:
        groups = [text_type.strip(group) for group in groups.split(",")]

    if output_yaml:
        for requirements in h.requirements.values():
            for requirement in requirements:
                if resolve and not requirement.version:
                    requirement.load_installed_version()
        click.echo(h.requirements.yaml)
    else:
        for group in groups:
            if not h.requirements[group]:
                continue
            click.echo("# {}".format(group))
            for requirement in h.requirements[group]:
                if resolve and not requirement.version:
                    requirement.load_installed_version()
                click.echo(str(requirement))
def visitdir(self, dir):
        m1dir = self.m1.visitdir(dir)
        m2dir = self.m2.visitdir(dir)

        # if both matchers return "all" then we know for sure we don't need
        # to visit this directory. Same if all matchers return False. In all
        # other case we have to visit a directory.
        if m1dir == "all" and m2dir == "all":
            return False
        if not m1dir and not m2dir:
            return False
        return True