Source code for logalpha.level

# This program is free software: you can redistribute it and/or modify it under the
# terms of the Apache License (v2.0) as published by the Apache Software Foundation.
#
# This program is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
# PARTICULAR PURPOSE. See the Apache License for more details.
#
# You should have received a copy of the Apache License along with this program.
# If not, see <https://www.apache.org/licenses/LICENSE-2.0>.

"""Level implementations."""


# type annotations
from __future__ import annotations
from typing import List

# standard libs
from dataclasses import dataclass


@dataclass
class Level:
    """
    A level associates a name and a value.

    Example:
        >>> level = Level(name='INFO', value=1)
        >>> level
        Level(name='INFO', value=1)
    """

    name: str
    value: int

    def __lt__(self, other: Level) -> bool:
        """
        Returns ``self.value < other.value``.

        Example:
            >>> a, b = Level.from_names(['A', 'B'])
            >>> assert a < b
            >>> assert b > a
        """
        return self.value < other.value

    def __gt__(self, other: Level) -> bool:
        """Similar to :meth:`Level.__lt__`."""
        return self.value > other.value

    def __le__(self, other: Level) -> bool:
        """Similar to :meth:`Level.__lt__`."""
        return self.value <= other.value

    def __ge__(self, other: Level) -> bool:
        """Similar to :meth:`Level.__lt__`."""
        return self.value >= other.value

    @classmethod
    def from_names(cls, names: List[str]) -> List[Level]:
        """
        Construct a set of contiguous Levels.

        Example:
            >>> levels = Level.from_names(['Ok', 'Err'])
            >>> levels
            [Level(name='Ok', value=0),
             Level(name='Err', value=1)]
        """
        return [cls(name, value) for value, name in enumerate(names)]


# List of canonical logging levels
LEVELS   = Level.from_names(['DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL'])  #:
DEBUG    = LEVELS[0]  #:
INFO     = LEVELS[1]  #:
WARNING  = LEVELS[2]  #:
ERROR    = LEVELS[3]  #:
CRITICAL = LEVELS[4]  #: