mercurial/thirdparty/tomli/_re.py

thirdparty: vendor tomli

The next commit will introduce a .toml file to abstract configitems
away from Python. Python 3.11 has a toml read-only library (`tomllib`), which
gives us a way out of vendoring eventually.

For now, we vendor the backport, specifically version 1.2.3 which is still
compatible with Python 3.6.

from datetime import date, datetime, time, timedelta, timezone, tzinfo
from functools import lru_cache
import re
from typing import Any, Optional, Union

from ._types import ParseFloat

# E.g.
# - 00:32:00.999999
# - 00:32:00
_TIME_RE_STR = r"([01][0-9]|2[0-3]):([0-5][0-9]):([0-5][0-9])(?:\.([0-9]{1,6})[0-9]*)?"

RE_NUMBER = re.compile(
    r"""
0
(?:
    x[0-9A-Fa-f](?:_?[0-9A-Fa-f])*   # hex
    |
    b[01](?:_?[01])*                 # bin
    |
    o[0-7](?:_?[0-7])*               # oct
)
|
[+-]?(?:0|[1-9](?:_?[0-9])*)         # dec, integer part
(?P<floatpart>
    (?:\.[0-9](?:_?[0-9])*)?         # optional fractional part
    (?:[eE][+-]?[0-9](?:_?[0-9])*)?  # optional exponent part
)
""",
    flags=re.VERBOSE,
)
RE_LOCALTIME = re.compile(_TIME_RE_STR)
RE_DATETIME = re.compile(
    fr"""
([0-9]{{4}})-(0[1-9]|1[0-2])-(0[1-9]|[12][0-9]|3[01])  # date, e.g. 1988-10-27
(?:
    [Tt ]
    {_TIME_RE_STR}
    (?:([Zz])|([+-])([01][0-9]|2[0-3]):([0-5][0-9]))?  # optional time offset
)?
""",
    flags=re.VERBOSE,
)


def match_to_datetime(match: "re.Match") -> Union[datetime, date]:
    """Convert a `RE_DATETIME` match to `datetime.datetime` or `datetime.date`.

    Raises ValueError if the match does not correspond to a valid date
    or datetime.
    """
    (
        year_str,
        month_str,
        day_str,
        hour_str,
        minute_str,
        sec_str,
        micros_str,
        zulu_time,
        offset_sign_str,
        offset_hour_str,
        offset_minute_str,
    ) = match.groups()
    year, month, day = int(year_str), int(month_str), int(day_str)
    if hour_str is None:
        return date(year, month, day)
    hour, minute, sec = int(hour_str), int(minute_str), int(sec_str)
    micros = int(micros_str.ljust(6, "0")) if micros_str else 0
    if offset_sign_str:
        tz: Optional[tzinfo] = cached_tz(
            offset_hour_str, offset_minute_str, offset_sign_str
        )
    elif zulu_time:
        tz = timezone.utc
    else:  # local date-time
        tz = None
    return datetime(year, month, day, hour, minute, sec, micros, tzinfo=tz)


@lru_cache(maxsize=None)
def cached_tz(hour_str: str, minute_str: str, sign_str: str) -> timezone:
    sign = 1 if sign_str == "+" else -1
    return timezone(
        timedelta(
            hours=sign * int(hour_str),
            minutes=sign * int(minute_str),
        )
    )


def match_to_localtime(match: "re.Match") -> time:
    hour_str, minute_str, sec_str, micros_str = match.groups()
    micros = int(micros_str.ljust(6, "0")) if micros_str else 0
    return time(int(hour_str), int(minute_str), int(sec_str), micros)


def match_to_number(match: "re.Match", parse_float: "ParseFloat") -> Any:
    if match.group("floatpart"):
        return parse_float(match.group())
    return int(match.group(), 0)