cpython/Lib/_pyrepl/simple_interact.py

#   Copyright 2000-2010 Michael Hudson-Doyle <micahel@gmail.com>
#                       Armin Rigo
#
#                        All Rights Reserved
#
#
# Permission to use, copy, modify, and distribute this software and
# its documentation for any purpose is hereby granted without fee,
# provided that the above copyright notice appear in all copies and
# that both that copyright notice and this permission notice appear in
# supporting documentation.
#
# THE AUTHOR MICHAEL HUDSON DISCLAIMS ALL WARRANTIES WITH REGARD TO
# THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
# AND FITNESS, IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL,
# INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
# RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
# CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

"""This is an alternative to python_reader which tries to emulate
the CPython prompt as closely as possible, with the exception of
allowing multiline input and multiline history entries.
"""

from __future__ import annotations

import _colorize  # type: ignore[import-not-found]
import _sitebuiltins
import linecache
import sys
import code
import ast
from types import ModuleType

from .readline import _get_reader, multiline_input
from .unix_console import _error


def check() -> str:
    """Returns the error message if there is a problem initializing the state."""
    try:
        _get_reader()
    except _error as e:
        return str(e) or repr(e) or "unknown error"
    return ""


def _strip_final_indent(text: str) -> str:
    # kill spaces and tabs at the end, but only if they follow '\n'.
    # meant to remove the auto-indentation only (although it would of
    # course also remove explicitly-added indentation).
    short = text.rstrip(" \t")
    n = len(short)
    if n > 0 and text[n - 1] == "\n":
        return short
    return text


def _clear_screen():
    reader = _get_reader()
    reader.scheduled_commands.append("clear_screen")


REPL_COMMANDS = {
    "exit": _sitebuiltins.Quitter('exit', ''),
    "quit": _sitebuiltins.Quitter('quit' ,''),
    "copyright": _sitebuiltins._Printer('copyright', sys.copyright),
    "help": "help",
    "clear": _clear_screen,
}

class InteractiveColoredConsole(code.InteractiveConsole):
    def __init__(
        self,
        locals: dict[str, object] | None = None,
        filename: str = "<console>",
        *,
        local_exit: bool = False,
    ) -> None:
        super().__init__(locals=locals, filename=filename, local_exit=local_exit)  # type: ignore[call-arg]
        self.can_colorize = _colorize.can_colorize()

    def showsyntaxerror(self, filename=None):
        super().showsyntaxerror(colorize=self.can_colorize)

    def showtraceback(self):
        super().showtraceback(colorize=self.can_colorize)

    def runsource(self, source, filename="<input>", symbol="single"):
        try:
            tree = ast.parse(source)
        except (OverflowError, SyntaxError, ValueError):
            self.showsyntaxerror(filename)
            return False
        if tree.body:
            *_, last_stmt = tree.body
        for stmt in tree.body:
            wrapper = ast.Interactive if stmt is last_stmt else ast.Module
            the_symbol = symbol if stmt is last_stmt else "exec"
            item = wrapper([stmt])
            try:
                code = compile(item, filename, the_symbol, dont_inherit=True)
            except (OverflowError, ValueError, SyntaxError):
                    self.showsyntaxerror(filename)
                    return False

            if code is None:
                return True

            self.runcode(code)
        return False


def run_multiline_interactive_console(
    mainmodule: ModuleType | None= None, future_flags: int = 0
) -> None:
    import __main__
    from .readline import _setup
    _setup()

    mainmodule = mainmodule or __main__
    console = InteractiveColoredConsole(mainmodule.__dict__, filename="<stdin>")
    if future_flags:
        console.compile.compiler.flags |= future_flags

    input_n = 0

    def maybe_run_command(statement: str) -> bool:
        statement = statement.strip()
        if statement in console.locals or statement not in REPL_COMMANDS:
            return False

        reader = _get_reader()
        reader.history.pop()  # skip internal commands in history
        command = REPL_COMMANDS[statement]
        if callable(command):
            command()
            return True

        if isinstance(command, str):
            # Internal readline commands require a prepared reader like
            # inside multiline_input.
            reader.prepare()
            reader.refresh()
            reader.do_cmd((command, [statement]))
            reader.restore()
            return True

        return False

    def more_lines(unicodetext: str) -> bool:
        # ooh, look at the hack:
        src = _strip_final_indent(unicodetext)
        try:
            code = console.compile(src, "<stdin>", "single")
        except (OverflowError, SyntaxError, ValueError):
            return False
        else:
            return code is None

    while 1:
        try:
            try:
                sys.stdout.flush()
            except Exception:
                pass

            ps1 = getattr(sys, "ps1", ">>> ")
            ps2 = getattr(sys, "ps2", "... ")
            try:
                statement = multiline_input(more_lines, ps1, ps2)
            except EOFError:
                break

            if maybe_run_command(statement):
                continue

            input_name = f"<python-input-{input_n}>"
            linecache._register_code(input_name, statement, "<stdin>")  # type: ignore[attr-defined]
            more = console.push(_strip_final_indent(statement), filename=input_name, _symbol="single")  # type: ignore[call-arg]
            assert not more
            input_n += 1
        except KeyboardInterrupt:
            console.write("\nKeyboardInterrupt\n")
            console.resetbuffer()
        except MemoryError:
            console.write("\nMemoryError\n")
            console.resetbuffer()