"""
    pygments.plugin
    ~~~~~~~~~~~~~~~

    Pygments setuptools plugin interface. The methods defined
    here also work if setuptools isn't installed but they just
    return nothing.

    lexer plugins::

        [pygments.lexers]
        yourlexer = yourmodule:YourLexer

    formatter plugins::

        [pygments.formatters]
        yourformatter = yourformatter:YourFormatter
        /.ext = yourformatter:YourFormatter

    As you can see, you can define extensions for the formatter
    with a leading slash.

    syntax plugins::

        [pygments.styles]
        yourstyle = yourstyle:YourStyle

    filter plugin::

        [pygments.filter]
        yourfilter = yourfilter:YourFilter


    :copyright: Copyright 2006-2021 by the Pygments team, see AUTHORS.
    :license: BSD, see LICENSE for details.
"""
LEXER_ENTRY_POINT = 'pygments.lexers'
FORMATTER_ENTRY_POINT = 'pygments.formatters'
STYLE_ENTRY_POINT = 'pygments.styles'
FILTER_ENTRY_POINT = 'pygments.filters'


def iter_entry_points(group_name):
    try:
        from pip._vendor import pkg_resources
    except (ImportError, OSError):
        return []

    return pkg_resources.iter_entry_points(group_name)


def find_plugin_lexers():
    for entrypoint in iter_entry_points(LEXER_ENTRY_POINT):
        yield entrypoint.load()


def find_plugin_formatters():
    for entrypoint in iter_entry_points(FORMATTER_ENTRY_POINT):
        yield entrypoint.name, entrypoint.load()


def find_plugin_styles():
    for entrypoint in iter_entry_points(STYLE_ENTRY_POINT):
        yield entrypoint.name, entrypoint.load()


def find_plugin_filters():
    for entrypoint in iter_entry_points(FILTER_ENTRY_POINT):
        yield entrypoint.name, entrypoint.load()