Class ReadlineAlikeReader

Lib/_pyrepl/readline.py:109–211

@dataclass(kw_only=True)
class ReadlineAlikeReader(historical_reader.HistoricalReader, CompletingReader):
    # Class fields
    assume_immutable_completions = False
    use_brackets = False
    sort_in_column = True

    # Instance fields
    config: ReadlineConfig
    more_lines: MoreLinesCallable | None = None
    last_used_indentation: str | None = None

    def __post_init__(self) -> None:
        super().__post_init__()
        self.commands["maybe_accept"] = maybe_accept
        self.commands["maybe-accept"] = maybe_accept
        self.commands["backspace_dedent"] = backspace_dedent
        self.commands["backspace-dedent"] = backspace_dedent

    def error(self, msg: str = "none") -> None:
        pass  # don't show error messages by default

    def get_stem(self) -> str:
        b = self.buffer
        p = self.pos - 1
        completer_delims = self.config.completer_delims
        while p >= 0 and b[p] not in completer_delims:
            p -= 1
        return "".join(b[p + 1 : self.pos])

    def get_completions(self, stem: str) -> tuple[list[str], CompletionAction | None]:
        module_completions = self.get_module_completions()
        if module_completions is not None:
            return module_completions
        if len(stem) == 0 and self.more_lines is not None:
            b = self.buffer
            p = self.pos
            while p > 0 and b[p - 1] != "\n":
                p -= 1
            num_spaces = 4 - ((self.pos - p) % 4)
            return [" " * num_spaces], None
        result = []
        function = self.config.readline_completer
        if function is not None:
            try:
                stem = str(stem)  # rlcompleter.py seems to not like unicode
            except UnicodeEncodeError:
                pass  # but feed unicode anyway if we have no choice
            state = 0
            while True:
                try:
                    next = function(stem, state)
                except Exception:
                    break
                if not isinstance(next, str):
                    break
                result.append(next)
                state += 1
            # Emulate readline's sorting using the visible text rather than