cpython/Lib/_pyrepl/historical_reader.py

#   Copyright 2000-2004 Michael Hudson-Doyle <micahel@gmail.com>
#
#                        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.

from __future__ import annotations

from contextlib import contextmanager
from dataclasses import dataclass, field

from . import commands, input
from .reader import Reader


if False:
    from .types import SimpleContextManager, KeySpec, CommandName


isearch_keymap: tuple[tuple[KeySpec, CommandName], ...] = tuple(
    [("\\%03o" % c, "isearch-end") for c in range(256) if chr(c) != "\\"]
    + [(c, "isearch-add-character") for c in map(chr, range(32, 127)) if c != "\\"]
    + [
        ("\\%03o" % c, "isearch-add-character")
        for c in range(256)
        if chr(c).isalpha() and chr(c) != "\\"
    ]
    + [
        ("\\\\", "self-insert"),
        (r"\C-r", "isearch-backwards"),
        (r"\C-s", "isearch-forwards"),
        (r"\C-c", "isearch-cancel"),
        (r"\C-g", "isearch-cancel"),
        (r"\<backspace>", "isearch-backspace"),
    ]
)

ISEARCH_DIRECTION_NONE = ""
ISEARCH_DIRECTION_BACKWARDS = "r"
ISEARCH_DIRECTION_FORWARDS = "f"


class next_history(commands.Command):
    def do(self) -> None:
        r = self.reader
        if r.historyi == len(r.history):
            r.error("end of history list")
            return
        r.select_item(r.historyi + 1)


class previous_history(commands.Command):
    def do(self) -> None:
        r = self.reader
        if r.historyi == 0:
            r.error("start of history list")
            return
        r.select_item(r.historyi - 1)


class restore_history(commands.Command):
    def do(self) -> None:
        r = self.reader
        if r.historyi != len(r.history):
            if r.get_unicode() != r.history[r.historyi]:
                r.buffer = list(r.history[r.historyi])
                r.pos = len(r.buffer)
                r.dirty = True


class first_history(commands.Command):
    def do(self) -> None:
        self.reader.select_item(0)


class last_history(commands.Command):
    def do(self) -> None:
        self.reader.select_item(len(self.reader.history))


class operate_and_get_next(commands.FinishCommand):
    def do(self) -> None:
        self.reader.next_history = self.reader.historyi + 1


class yank_arg(commands.Command):
    def do(self) -> None:
        r = self.reader
        if r.last_command is self.__class__:
            r.yank_arg_i += 1
        else:
            r.yank_arg_i = 0
        if r.historyi < r.yank_arg_i:
            r.error("beginning of history list")
            return
        a = r.get_arg(-1)
        # XXX how to split?
        words = r.get_item(r.historyi - r.yank_arg_i - 1).split()
        if a < -len(words) or a >= len(words):
            r.error("no such arg")
            return
        w = words[a]
        b = r.buffer
        if r.yank_arg_i > 0:
            o = len(r.yank_arg_yanked)
        else:
            o = 0
        b[r.pos - o : r.pos] = list(w)
        r.yank_arg_yanked = w
        r.pos += len(w) - o
        r.dirty = True


class forward_history_isearch(commands.Command):
    def do(self) -> None:
        r = self.reader
        r.isearch_direction = ISEARCH_DIRECTION_FORWARDS
        r.isearch_start = r.historyi, r.pos
        r.isearch_term = ""
        r.dirty = True
        r.push_input_trans(r.isearch_trans)


class reverse_history_isearch(commands.Command):
    def do(self) -> None:
        r = self.reader
        r.isearch_direction = ISEARCH_DIRECTION_BACKWARDS
        r.dirty = True
        r.isearch_term = ""
        r.push_input_trans(r.isearch_trans)
        r.isearch_start = r.historyi, r.pos


class isearch_cancel(commands.Command):
    def do(self) -> None:
        r = self.reader
        r.isearch_direction = ISEARCH_DIRECTION_NONE
        r.pop_input_trans()
        r.select_item(r.isearch_start[0])
        r.pos = r.isearch_start[1]
        r.dirty = True


class isearch_add_character(commands.Command):
    def do(self) -> None:
        r = self.reader
        b = r.buffer
        r.isearch_term += self.event[-1]
        r.dirty = True
        p = r.pos + len(r.isearch_term) - 1
        if b[p : p + 1] != [r.isearch_term[-1]]:
            r.isearch_next()


class isearch_backspace(commands.Command):
    def do(self) -> None:
        r = self.reader
        if len(r.isearch_term) > 0:
            r.isearch_term = r.isearch_term[:-1]
            r.dirty = True
        else:
            r.error("nothing to rubout")


class isearch_forwards(commands.Command):
    def do(self) -> None:
        r = self.reader
        r.isearch_direction = ISEARCH_DIRECTION_FORWARDS
        r.isearch_next()


class isearch_backwards(commands.Command):
    def do(self) -> None:
        r = self.reader
        r.isearch_direction = ISEARCH_DIRECTION_BACKWARDS
        r.isearch_next()


class isearch_end(commands.Command):
    def do(self) -> None:
        r = self.reader
        r.isearch_direction = ISEARCH_DIRECTION_NONE
        r.console.forgetinput()
        r.pop_input_trans()
        r.dirty = True


@dataclass
class HistoricalReader(Reader):
    """Adds history support (with incremental history searching) to the
    Reader class.
    """

    history: list[str] = field(default_factory=list)
    historyi: int = 0
    next_history: int | None = None
    transient_history: dict[int, str] = field(default_factory=dict)
    isearch_term: str = ""
    isearch_direction: str = ISEARCH_DIRECTION_NONE
    isearch_start: tuple[int, int] = field(init=False)
    isearch_trans: input.KeymapTranslator = field(init=False)
    yank_arg_i: int = 0
    yank_arg_yanked: str = ""

    def __post_init__(self) -> None:
        super().__post_init__()
        for c in [
            next_history,
            previous_history,
            restore_history,
            first_history,
            last_history,
            yank_arg,
            forward_history_isearch,
            reverse_history_isearch,
            isearch_end,
            isearch_add_character,
            isearch_cancel,
            isearch_add_character,
            isearch_backspace,
            isearch_forwards,
            isearch_backwards,
            operate_and_get_next,
        ]:
            self.commands[c.__name__] = c
            self.commands[c.__name__.replace("_", "-")] = c
        self.isearch_start = self.historyi, self.pos
        self.isearch_trans = input.KeymapTranslator(
            isearch_keymap, invalid_cls=isearch_end, character_cls=isearch_add_character
        )

    def collect_keymap(self) -> tuple[tuple[KeySpec, CommandName], ...]:
        return super().collect_keymap() + (
            (r"\C-n", "next-history"),
            (r"\C-p", "previous-history"),
            (r"\C-o", "operate-and-get-next"),
            (r"\C-r", "reverse-history-isearch"),
            (r"\C-s", "forward-history-isearch"),
            (r"\M-r", "restore-history"),
            (r"\M-.", "yank-arg"),
            (r"\<page down>", "last-history"),
            (r"\<page up>", "first-history"),
        )

    def select_item(self, i: int) -> None:
        self.transient_history[self.historyi] = self.get_unicode()
        buf = self.transient_history.get(i)
        if buf is None:
            buf = self.history[i].rstrip()
        self.buffer = list(buf)
        self.historyi = i
        self.pos = len(self.buffer)
        self.dirty = True

    def get_item(self, i: int) -> str:
        if i != len(self.history):
            return self.transient_history.get(i, self.history[i])
        else:
            return self.transient_history.get(i, self.get_unicode())

    @contextmanager
    def suspend(self) -> SimpleContextManager:
        with super().suspend():
            try:
                old_history = self.history[:]
                del self.history[:]
                yield
            finally:
                self.history[:] = old_history

    def prepare(self) -> None:
        super().prepare()
        try:
            self.transient_history = {}
            if self.next_history is not None and self.next_history < len(self.history):
                self.historyi = self.next_history
                self.buffer[:] = list(self.history[self.next_history])
                self.pos = len(self.buffer)
                self.transient_history[len(self.history)] = ""
            else:
                self.historyi = len(self.history)
            self.next_history = None
        except:
            self.restore()
            raise

    def get_prompt(self, lineno: int, cursor_on_line: bool) -> str:
        if cursor_on_line and self.isearch_direction != ISEARCH_DIRECTION_NONE:
            d = "rf"[self.isearch_direction == ISEARCH_DIRECTION_FORWARDS]
            return "(%s-search `%s') " % (d, self.isearch_term)
        else:
            return super().get_prompt(lineno, cursor_on_line)

    def isearch_next(self) -> None:
        st = self.isearch_term
        p = self.pos
        i = self.historyi
        s = self.get_unicode()
        forwards = self.isearch_direction == ISEARCH_DIRECTION_FORWARDS
        while 1:
            if forwards:
                p = s.find(st, p + 1)
            else:
                p = s.rfind(st, 0, p + len(st) - 1)
            if p != -1:
                self.select_item(i)
                self.pos = p
                return
            elif (forwards and i >= len(self.history) - 1) or (not forwards and i == 0):
                self.error("not found")
                return
            else:
                if forwards:
                    i += 1
                    s = self.get_item(i)
                    p = -1
                else:
                    i -= 1
                    s = self.get_item(i)
                    p = len(s)

    def finish(self) -> None:
        super().finish()
        ret = self.get_unicode()
        for i, t in self.transient_history.items():
            if i < len(self.history) and i != self.historyi:
                self.history[i] = t
        if ret and should_auto_add_history:
            self.history.append(ret)


should_auto_add_history = True