codekingpro/portable-devtools

1import codecs2import re3from typing import (4    IO,5    Iterator,6    Match,7    NamedTuple,8    Optional,9    Pattern,10    Sequence,11)12 13 14def make_regex(string: str, extra_flags: int = 0) -> Pattern[str]:15    return re.compile(string, re.UNICODE | extra_flags)16 17 18_newline = make_regex(r"(\r\n|\n|\r)")19_multiline_whitespace = make_regex(r"\s*", extra_flags=re.MULTILINE)20_whitespace = make_regex(r"[^\S\r\n]*")21_export = make_regex(r"(?:export[^\S\r\n]+)?")22_single_quoted_key = make_regex(r"'([^']+)'")23_unquoted_key = make_regex(r"([^=\#\s]+)")24_equal_sign = make_regex(r"(=[^\S\r\n]*)")25_single_quoted_value = make_regex(r"'((?:\\'|[^'])*)'")26_double_quoted_value = make_regex(r'"((?:\\"|[^"])*)"')27_unquoted_value = make_regex(r"([^\r\n]*)")28_comment = make_regex(r"(?:[^\S\r\n]*#[^\r\n]*)?")29_end_of_line = make_regex(r"[^\S\r\n]*(?:\r\n|\n|\r|$)")30_rest_of_line = make_regex(r"[^\r\n]*(?:\r|\n|\r\n)?")31_double_quote_escapes = make_regex(r"\\[\\'\"abfnrtv]")32_single_quote_escapes = make_regex(r"\\[\\']")33 34 35class Original(NamedTuple):36    string: str37    line: int38 39 40class Binding(NamedTuple):41    key: Optional[str]42    value: Optional[str]43    original: Original44    error: bool45 46 47class Position:48    def __init__(self, chars: int, line: int) -> None:49        self.chars = chars50        self.line = line51 52    @classmethod53    def start(cls) -> "Position":54        return cls(chars=0, line=1)55 56    def set(self, other: "Position") -> None:57        self.chars = other.chars58        self.line = other.line59 60    def advance(self, string: str) -> None:61        self.chars += len(string)62        self.line += len(re.findall(_newline, string))63 64 65class Error(Exception):66    pass67 68 69class Reader:70    def __init__(self, stream: IO[str]) -> None:71        self.string = stream.read()72        self.position = Position.start()73        self.mark = Position.start()74 75    def has_next(self) -> bool:76        return self.position.chars < len(self.string)77 78    def set_mark(self) -> None:79        self.mark.set(self.position)80 81    def get_marked(self) -> Original:82        return Original(83            string=self.string[self.mark.chars : self.position.chars],84            line=self.mark.line,85        )86 87    def peek(self, count: int) -> str:88        return self.string[self.position.chars : self.position.chars + count]89 90    def read(self, count: int) -> str:91        result = self.string[self.position.chars : self.position.chars + count]92        if len(result) < count:93            raise Error("read: End of string")94        self.position.advance(result)95        return result96 97    def read_regex(self, regex: Pattern[str]) -> Sequence[str]:98        match = regex.match(self.string, self.position.chars)99        if match is None:100            raise Error("read_regex: Pattern not found")101        self.position.advance(self.string[match.start() : match.end()])102        return match.groups()103 104 105def decode_escapes(regex: Pattern[str], string: str) -> str:106    def decode_match(match: Match[str]) -> str:107        return codecs.decode(match.group(0), "unicode-escape")  # type: ignore108 109    return regex.sub(decode_match, string)110 111 112def parse_key(reader: Reader) -> Optional[str]:113    char = reader.peek(1)114    if char == "#":115        return None116    elif char == "'":117        (key,) = reader.read_regex(_single_quoted_key)118    else:119        (key,) = reader.read_regex(_unquoted_key)120    return key121 122 123def parse_unquoted_value(reader: Reader) -> str:124    (part,) = reader.read_regex(_unquoted_value)125    return re.sub(r"\s+#.*", "", part).rstrip()126 127 128def parse_value(reader: Reader) -> str:129    char = reader.peek(1)130    if char == "'":131        (value,) = reader.read_regex(_single_quoted_value)132        return decode_escapes(_single_quote_escapes, value)133    elif char == '"':134        (value,) = reader.read_regex(_double_quoted_value)135        return decode_escapes(_double_quote_escapes, value)136    elif char in ("", "\n", "\r"):137        return ""138    else:139        return parse_unquoted_value(reader)140 141 142def parse_binding(reader: Reader) -> Binding:143    reader.set_mark()144    try:145        reader.read_regex(_multiline_whitespace)146        if not reader.has_next():147            return Binding(148                key=None,149                value=None,150                original=reader.get_marked(),151                error=False,152            )153        reader.read_regex(_export)154        key = parse_key(reader)155        reader.read_regex(_whitespace)156        if reader.peek(1) == "=":157            reader.read_regex(_equal_sign)158            value: Optional[str] = parse_value(reader)159        else:160            value = None161        reader.read_regex(_comment)162        reader.read_regex(_end_of_line)163        return Binding(164            key=key,165            value=value,166            original=reader.get_marked(),167            error=False,168        )169    except Error:170        reader.read_regex(_rest_of_line)171        return Binding(172            key=None,173            value=None,174            original=reader.get_marked(),175            error=True,176        )177 178 179def parse_stream(stream: IO[str]) -> Iterator[Binding]:180    reader = Reader(stream)181    while reader.has_next():182        yield parse_binding(reader)183