# Copyright 2000-2010 Michael Hudson-Doyle <[email protected]>
# Antonio Cuni
# 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.
from __future__ import annotations
import sys
from contextlib import contextmanager
from dataclasses import dataclass, field, fields
import unicodedata
from _colorize import can_colorize, ANSIColors # type: ignore[import-not-found]
from . import commands, console, input
from .utils import ANSI_ESCAPE_SEQUENCE, wlen, str_width
from .trace import trace
# types
Command = commands.Command
from .types import Callback, SimpleContextManager, KeySpec, CommandName
def disp_str(buffer: str) -> tuple[str, list[int]]:
"""disp_str(buffer:string) -> (string, [int])
Return the string that should be the printed representation of
|buffer| and a list detailing where the characters of |buffer|
get used up. E.g.:
>>> disp_str(chr(3))
('^C', [1, 0])
"""
b: list[int] = []
s: list[str] = []
for c in buffer:
if c == '\x1a':
s.append(c)
b.append(2)
elif ord(c) < 128:
s.append(c)
b.append(1)
elif unicodedata.category(c).startswith("C"):
c = r"\u%04x" % ord(c)
s.append(c)
b.extend([0] * (len(c) - 1))
else:
s.append(c)
b.append(str_width(c))
return "".join(s), b
# syntax classes:
SYNTAX_WHITESPACE, SYNTAX_WORD, SYNTAX_SYMBOL = range(3)
def make_default_syntax_table() -> dict[str, int]:
# XXX perhaps should use some unicodedata here?
st: dict[str, int] = {}
for c in map(chr, range(256)):
st[c] = SYNTAX_SYMBOL
for c in [a for a in map(chr, range(256)) if a.isalnum()]:
st[c] = SYNTAX_WORD
st["\n"] = st[" "] = SYNTAX_WHITESPACE
return st
def make_default_commands() -> dict[CommandName, type[Command]]:
result: dict[CommandName, type[Command]] = {}
for v in vars(commands).values():
if isinstance(v, type) and issubclass(v, Command) and v.__name__[0].islower():
result[v.__name__] = v
result[v.__name__.replace("_", "-")] = v
return result
default_keymap: tuple[tuple[KeySpec, CommandName], ...] = tuple(
[
(r"\C-a", "beginning-of-line"),
(r"\C-b", "left"),
(r"\C-c", "interrupt"),
(r"\C-d", "delete"),
(r"\C-e", "end-of-line"),
(r"\C-f", "right"),
(r"\C-g", "cancel"),
(r"\C-h", "backspace"),
(r"\C-j", "accept"),
(r"\<return>", "accept"),
(r"\C-k", "kill-line"),
(r"\C-l", "clear-screen"),
(r"\C-m", "accept"),
(r"\C-t", "transpose-characters"),
(r"\C-u", "unix-line-discard"),
(r"\C-w", "unix-word-rubout"),
(r"\C-x\C-u", "upcase-region"),
(r"\C-y", "yank"),
*(() if sys.platform == "win32" else ((r"\C-z", "suspend"), )),
(r"\M-b", "backward-word"),
(r"\M-c", "capitalize-word"),
(r"\M-d", "kill-word"),
(r"\M-f", "forward-word"),
(r"\M-l", "downcase-word"),
(r"\M-t", "transpose-words"),
(r"\M-u", "upcase-word"),
(r"\M-y", "yank-pop"),
(r"\M--", "digit-arg"),
(r"\M-0", "digit-arg"),
(r"\M-1", "digit-arg"),
(r"\M-2", "digit-arg"),
(r"\M-3", "digit-arg"),
(r"\M-4", "digit-arg"),
(r"\M-5", "digit-arg"),
(r"\M-6", "digit-arg"),
(r"\M-7", "digit-arg"),
(r"\M-8", "digit-arg"),
(r"\M-9", "digit-arg"),
(r"\M-\n", "accept"),
("\\\\", "self-insert"),
(r"\x1b[200~", "enable_bracketed_paste"),
(r"\x1b[201~", "disable_bracketed_paste"),
(r"\x03", "ctrl-c"),
]
+ [(c, "self-insert") for c in map(chr, range(32, 127)) if c != "\\"]
+ [(c, "self-insert") for c in map(chr, range(128, 256)) if c.isalpha()]
+ [
(r"\<up>", "up"),
(r"\<down>", "down"),
(r"\<left>", "left"),
(r"\C-\<left>", "backward-word"),
(r"\<right>", "right"),
(r"\C-\<right>", "forward-word"),
(r"\<delete>", "delete"),
(r"\x1b[3~", "delete"),
(r"\<backspace>", "backspace"),
(r"\M-\<backspace>", "backward-kill-word"),
(r"\<end>", "end-of-line"), # was 'end'
(r"\<home>", "beginning-of-line"), # was 'home'
(r"\<f1>", "help"),
(r"\<f2>", "show-history"),
(r"\<f3>", "paste-mode"),
(r"\EOF", "end"), # the entries in the terminfo database for xterms
(r"\EOH", "home"), # seem to be wrong. this is a less than ideal
# workaround
]
)
@dataclass(slots=True)
class Reader:
"""The Reader class implements the bare bones of a command reader,
handling such details as editing and cursor motion. What it does
not support are such things as completion or history support -
these are implemented elsewhere.
Instance variables of note include:
* buffer:
A *list* (*not* a string at the moment :-) containing all the
characters that have been entered.
* console:
Hopefully encapsulates the OS dependent stuff.
* pos:
A 0-based index into 'buffer' for where the insertion point
is.
* screeninfo:
Ahem. This list contains some info needed to move the
insertion point around reasonably efficiently.
* cxy, lxy:
the position of the insertion point in screen ...
* syntax_table:
Dictionary mapping characters to 'syntax class'; read the
emacs docs to see what this means :-)
* commands:
Dictionary mapping command names to command classes.
* arg:
The emacs-style prefix argument. It will be None if no such
argument has been provided.
* dirty:
True if we need to refresh the display.
* kill_ring:
The emacs-style kill-ring; manipulated with yank & yank-pop
* ps1, ps2, ps3, ps4:
prompts. ps1 is the prompt for a one-line input; for a
multiline input it looks like:
ps2> first line of input goes here
ps3> second and further
ps3> lines get ps3
...
ps4> and the last one gets ps4
As with the usual top-level, you can set these to instances if
you like; str() will be called on them (once) at the beginning
of each command. Don't put really long or newline containing
strings here, please!
This is just the default policy; you can change it freely by
overriding get_prompt() (and indeed some standard subclasses
do).
* finished:
handle1 will set this to a true value if a command signals
that we're done.
"""
console: console.Console
## state
buffer: list[str] = field(default_factory=list)
pos: int = 0
ps1: str = "->> "
ps2: str = "/>> "
ps3: str = "|.. "
ps4: str = R"\__ "
kill_ring: list[list[str]] = field(default_factory=list)
msg: str = ""
arg: int | None = None
dirty: bool = False
finished: bool = False
paste_mode: bool = False
in_bracketed_paste: bool = False
commands: dict[str, type[Command]] = field(default_factory=make_default_commands)
last_command: type[Command] | None = None
syntax_table: dict[str, int] = field(default_factory=make_default_syntax_table)
keymap: tuple[tuple[str, str], ...] = ()
input_trans: input.KeymapTranslator = field(init=False)
input_trans_stack: list[input.KeymapTranslator] = field(default_factory=list)
screen: list[str] = field(default_factory=list)
screeninfo: list[tuple[int, list[int]]] = field(init=False)
cxy: tuple[int, int] = field(init=False)
lxy: tuple[int, int] = field(init=False)
scheduled_commands: list[str] = field(default_factory=list)
can_colorize: bool = False
threading_hook: Callback | None = None
## cached metadata to speed up screen refreshes
@dataclass
class RefreshCache:
in_bracketed_paste: bool = False
screen: list[str] = field(default_factory=list)
screeninfo: list[tuple[int, list[int]]] = field(init=False)
line_end_offsets: list[int] = field(default_factory=list)
pos: int = field(init=False)
cxy: tuple[int, int] = field(init=False)
dimensions: tuple[int, int] = field(init=False)
invalidated: bool = False
def update_cache(self,
reader: Reader,
screen: list[str],
screeninfo: list[tuple[int, list[int]]],
) -> None:
self.in_bracketed_paste = reader.in_bracketed_paste
self.screen = screen.copy()
self.screeninfo = screeninfo.copy()
self.pos = reader.pos
self.cxy = reader.cxy
self.dimensions = reader.console.width, reader.console.height
self.invalidated = False
def valid(self, reader: Reader) -> bool:
if self.invalidated:
return False
dimensions = reader.console.width, reader.console.height
dimensions_changed = dimensions != self.dimensions
paste_changed = reader.in_bracketed_paste != self.in_bracketed_paste
return not (dimensions_changed or paste_changed)
def get_cached_location(self, reader: Reader) -> tuple[int, int]:
if self.invalidated:
raise ValueError("Cache is invalidated")
offset = 0
earliest_common_pos = min(reader.pos, self.pos)
num_common_lines = len(self.line_end_offsets)
while num_common_lines > 0:
offset = self.line_end_offsets[num_common_lines - 1]
if earliest_common_pos > offset:
break
num_common_lines -= 1
else:
offset = 0
return offset, num_common_lines
last_refresh_cache: RefreshCache = field(default_factory=RefreshCache)
def __post_init__(self) -> None:
# Enable the use of `insert` without a `prepare` call - necessary to
# facilitate the tab completion hack implemented for
# <https://bugs.python.org/issue25660>.
self.keymap = self.collect_keymap()
self.input_trans = input.KeymapTranslator(
self.keymap, invalid_cls="invalid-key", character_cls="self-insert"
)
self.screeninfo = [(0, [])]
self.cxy = self.pos2xy()
self.lxy = (self.pos, 0)
self.can_colorize = can_colorize()
self.last_refresh_cache.screeninfo = self.screeninfo
self.last_refresh_cache.pos = self.pos
self.last_refresh_cache.cxy = self.cxy
self.last_refresh_cache.dimensions = (0, 0)
def collect_keymap(self) -> tuple[tuple[KeySpec, CommandName], ...]:
return default_keymap
def calc_screen(self) -> list[str]:
"""Translate changes in self.buffer into changes in self.console.screen."""
# Since the last call to calc_screen:
# screen and screeninfo may differ due to a completion menu being shown
# pos and cxy may differ due to edits, cursor movements, or completion menus
# Lines that are above both the old and new cursor position can't have changed,
# unless the terminal has been resized (which might cause reflowing) or we've
# entered or left paste mode (which changes prompts, causing reflowing).
num_common_lines = 0
offset = 0
if self.last_refresh_cache.valid(self):
offset, num_common_lines = self.last_refresh_cache.get_cached_location(self)
screen = self.last_refresh_cache.screen
del screen[num_common_lines:]
screeninfo = self.last_refresh_cache.screeninfo
del screeninfo[num_common_lines:]
last_refresh_line_end_offsets = self.last_refresh_cache.line_end_offsets
del last_refresh_line_end_offsets[num_common_lines:]
pos = self.pos
pos -= offset
prompt_from_cache = (offset and self.buffer[offset - 1] != "\n")
lines = "".join(self.buffer[offset:]).split("\n")
cursor_found = False
lines_beyond_cursor = 0
for ln, line in enumerate(lines, num_common_lines):
ll = len(line)
if 0 <= pos <= ll:
self.lxy = pos, ln
cursor_found = True
elif cursor_found:
lines_beyond_cursor += 1
if lines_beyond_cursor > self.console.height:
# No need to keep formatting lines.
# The console can't show them.
break
if prompt_from_cache:
# Only the first line's prompt can come from the cache
prompt_from_cache = False
prompt = ""
else:
prompt = self.get_prompt(ln, ll >= pos >= 0)
while "\n" in prompt:
pre_prompt, _, prompt = prompt.partition("\n")
last_refresh_line_end_offsets.append(offset)
screen.append(pre_prompt)
screeninfo.append((0, []))
pos -= ll + 1
prompt, lp = self.process_prompt(prompt)
l, l2 = disp_str(line)
wrapcount = (wlen(l) + lp) // self.console.width
if wrapcount == 0:
offset += ll + 1 # Takes all of the line plus the newline
last_refresh_line_end_offsets.append(offset)
screen.append(prompt + l)
screeninfo.append((lp, l2))
else:
i = 0
while l:
prelen = lp if i == 0 else 0
index_to_wrap_before = 0
column = 0
for character_width in l2:
if column + character_width >= self.console.width - prelen:
break
index_to_wrap_before += 1
column += character_width
pre = prompt if i == 0 else ""
if len(l) > index_to_wrap_before:
offset += index_to_wrap_before
post = "\\"
after = [1]
else:
offset += index_to_wrap_before + 1 # Takes the newline
post = ""
after = []
last_refresh_line_end_offsets.append(offset)
screen.append(pre + l[:index_to_wrap_before] + post)
screeninfo.append((prelen, l2[:index_to_wrap_before] + after))
l = l[index_to_wrap_before:]
l2 = l2[index_to_wrap_before:]
i += 1
self.screeninfo = screeninfo
self.cxy = self.pos2xy()
if self.msg:
for mline in self.msg.split("\n"):
screen.append(mline)
screeninfo.append((0, []))
self.last_refresh_cache.update_cache(self, screen, screeninfo)
return screen
@staticmethod
def process_prompt(prompt: str) -> tuple[str, int]:
"""Process the prompt.
This means calculate the length of the prompt. The character \x01
and \x02 are used to bracket ANSI control sequences and need to be
excluded from the length calculation. So also a copy of the prompt
is returned with these control characters removed."""
# The logic below also ignores the length of common escape
# sequences if they were not explicitly within \x01...\x02.
# They are CSI (or ANSI) sequences ( ESC [ ... LETTER )
# wlen from utils already excludes ANSI_ESCAPE_SEQUENCE chars,
# which breaks the logic below so we redefine it here.
def wlen(s: str) -> int:
return sum(str_width(i) for i in s)
out_prompt = ""
l = wlen(prompt)
pos = 0
while True:
s = prompt.find("\x01", pos)
if s == -1:
break
e = prompt.find("\x02", s)
if e == -1:
break
# Found start and end brackets, subtract from string length
l = l - (e - s + 1)
keep = prompt[pos:s]
l -= sum(map(wlen, ANSI_ESCAPE_SEQUENCE.findall(keep)))
out_prompt += keep + prompt[s + 1 : e]
pos = e + 1
keep = prompt[pos:]
l -= sum(map(wlen, ANSI_ESCAPE_SEQUENCE.findall(keep)))
out_prompt += keep
return out_prompt, l
def bow(self, p: int | None = None) -> int:
"""Return the 0-based index of the word break preceding p most
immediately.
p defaults to self.pos; word boundaries are determined using
self.syntax_table."""
if p is None:
p = self.pos
st = self.syntax_table
b = self.buffer
p -= 1
while p >= 0 and st.get(b[p], SYNTAX_WORD) != SYNTAX_WORD:
p -= 1
while p >= 0 and st.get(b[p], SYNTAX_WORD) == SYNTAX_WORD:
p -= 1
return p + 1
def eow(self, p: int | None = None) -> int:
"""Return the 0-based index of the word break following p most
immediately.
p defaults to self.pos; word boundaries are determined using
self.syntax_table."""
if p is None:
p = self.pos
st = self.syntax_table
b = self.buffer
while p < len(b) and st.get(b[p], SYNTAX_WORD) != SYNTAX_WORD:
p += 1
while p < len(b) and st.get(b[p], SYNTAX_WORD) == SYNTAX_WORD:
p += 1
return p
def bol(self, p: int | None = None) -> int:
"""Return the 0-based index of the line break preceding p most
immediately.
p defaults to self.pos."""
if p is None:
p = self.pos
b = self.buffer
p -= 1
while p >= 0 and b[p] != "\n":
p -= 1
return p + 1
def eol(self, p: int | None = None) -> int:
"""Return the 0-based index of the line break following p most
immediately.
p defaults to self.pos."""
if p is None:
p = self.pos
b = self.buffer
while p < len(b) and b[p] != "\n":
p += 1
return p
def max_column(self, y: int) -> int:
"""Return the last x-offset for line y"""
return self.screeninfo[y][0] + sum(self.screeninfo[y][1])
def max_row(self) -> int:
return len(self.screeninfo) - 1
def get_arg(self, default: int = 1) -> int:
"""Return any prefix argument that the user has supplied,
returning 'default' if there is None. Defaults to 1.
"""
if self.arg is None:
return default
return self.arg
def get_prompt(self, lineno: int, cursor_on_line: bool) -> str:
"""Return what should be in the left-hand margin for line
'lineno'."""
if self.arg is not None and cursor_on_line:
prompt = f"(arg: {self.arg}) "
elif self.paste_mode and not self.in_bracketed_paste:
prompt = "(paste) "
elif "\n" in self.buffer:
if lineno == 0:
prompt = self.ps2
elif self.ps4 and lineno == self.buffer.count("\n"):
prompt = self.ps4
else:
prompt = self.ps3
else:
prompt = self.ps1
if self.can_colorize:
prompt = f"{ANSIColors.BOLD_MAGENTA}{prompt}{ANSIColors.RESET}"
return prompt
def push_input_trans(self, itrans: input.KeymapTranslator) -> None:
self.input_trans_stack.append(self.input_trans)
self.input_trans = itrans
def pop_input_trans(self) -> None:
self.input_trans = self.input_trans_stack.pop()
def setpos_from_xy(self, x: int, y: int) -> None:
"""Set pos according to coordinates x, y"""
pos = 0
i = 0
while i < y:
prompt_len, character_widths = self.screeninfo[i]
offset = len(character_widths) - character_widths.count(0)
in_wrapped_line = prompt_len + sum(character_widths) >= self.console.width
if in_wrapped_line:
pos += offset - 1 # -1 cause backslash is not in buffer
else:
pos += offset + 1 # +1 cause newline is in buffer
i += 1
j = 0
cur_x = self.screeninfo[i][0]
while cur_x < x:
if self.screeninfo[i][1][j] == 0:
continue
cur_x += self.screeninfo[i][1][j]
j += 1
pos += 1
self.pos = pos
def pos2xy(self) -> tuple[int, int]:
"""Return the x, y coordinates of position 'pos'."""
# this *is* incomprehensible, yes.
y = 0
pos = self.pos
assert 0 <= pos <= len(self.buffer)
if pos == len(self.buffer):
y = len(self.screeninfo) - 1
p, l2 = self.screeninfo[y]
return p + sum(l2) + l2.count(0), y
for p, l2 in self.screeninfo:
l = len(l2) - l2.count(0)
in_wrapped_line = p + sum(l2) >= self.console.width
offset = l - 1 if in_wrapped_line else l # need to remove backslash
if offset >= pos:
break
if p + sum(l2) >= self.console.width:
pos -= l - 1 # -1 cause backslash is not in buffer
else:
pos -= l + 1 # +1 cause newline is in buffer
y += 1
return p + sum(l2[:pos]), y
def insert(self, text: str | list[str]) -> None:
"""Insert 'text' at the insertion point."""
self.buffer[self.pos : self.pos] = list(text)
self.pos += len(text)
self.dirty = True
def update_cursor(self) -> None:
"""Move the cursor to reflect changes in self.pos"""
self.cxy = self.pos2xy()
self.console.move_cursor(*self.cxy)
def after_command(self, cmd: Command) -> None:
"""This function is called to allow post command cleanup."""
if getattr(cmd, "kills_digit_arg", True):
if self.arg is not None:
self.dirty = True
self.arg = None
def prepare(self) -> None:
"""Get ready to run. Call restore when finished. You must not
write to the console in between the calls to prepare and
restore."""
try:
self.console.prepare()
self.arg = None
self.finished = False
del self.buffer[:]
self.pos = 0
self.dirty = True
self.last_command = None
self.calc_screen()
except BaseException:
self.restore()
raise
while self.scheduled_commands:
cmd = self.scheduled_commands.pop()
self.do_cmd((cmd, []))
def last_command_is(self, cls: type) -> bool:
if not self.last_command:
return False
return issubclass(cls, self.last_command)
def restore(self) -> None:
"""Clean up after a run."""
self.console.restore()
@contextmanager
def suspend(self) -> SimpleContextManager:
"""A context manager to delegate to another reader."""
prev_state = {f.name: getattr(self, f.name) for f in fields(self)}
try:
self.restore()
yield
finally:
for arg in ("msg", "ps1", "ps2", "ps3", "ps4", "paste_mode"):
setattr(self, arg, prev_state[arg])
self.prepare()
def finish(self) -> None:
"""Called when a command signals that we're finished."""
pass
def error(self, msg: str = "none") -> None:
self.msg = "! " + msg + " "
self.dirty = True
self.console.beep()
def update_screen(self) -> None:
if self.dirty:
self.refresh()
def refresh(self) -> None:
"""Recalculate and refresh the screen."""
if self.in_bracketed_paste and self.buffer and not self.buffer[-1] == "\n":
return
# this call sets up self.cxy, so call it first.
self.screen = self.calc_screen()
self.console.refresh(self.screen, self.cxy)
self.dirty = False
def do_cmd(self, cmd: tuple[str, list[str]]) -> None:
"""`cmd` is a tuple of "event_name" and "event", which in the current
implementation is always just the "buffer" which happens to be a list
of single-character strings."""
trace("received command {cmd}", cmd=cmd)
if isinstance(cmd[0], str):
command_type = self.commands.get(cmd[0], commands.invalid_command)
elif isinstance(cmd[0], type):
command_type = cmd[0]
else:
return # nothing to do
command = command_type(self, *cmd) # type: ignore[arg-type]
command.do()
self.after_command(command)
if self.dirty:
self.refresh()
else:
self.update_cursor()
if not isinstance(cmd, commands.digit_arg):
self.last_command = command_type
self.finished = bool(command.finish)
if self.finished:
self.console.finish()
self.finish()
def run_hooks(self) -> None:
threading_hook = self.threading_hook
if threading_hook is None and 'threading' in sys.modules:
from ._threading_handler import install_threading_hook
install_threading_hook(self)
if threading_hook is not None:
try:
threading_hook()
except Exception:
pass
input_hook = self.console.input_hook
if input_hook:
try:
input_hook()
except Exception:
pass
def handle1(self, block: bool = True) -> bool:
"""Handle a single event. Wait as long as it takes if block
is true (the default), otherwise return False if no event is
pending."""
if self.msg:
self.msg = ""
self.dirty = True
while True:
# We use the same timeout as in readline.c: 100ms
self.run_hooks()
self.console.wait(100)
event = self.console.get_event(block=False)
if not event:
if block:
continue
return False
translate = True
if event.evt == "key":
self.input_trans.push(event)
elif event.evt == "scroll":
self.refresh()
elif event.evt == "resize":
self.refresh()
else:
translate = False
if translate:
cmd = self.input_trans.get()
else:
cmd = [event.evt, event.data]
if cmd is None:
if block:
continue
return False
self.do_cmd(cmd)
return True
def push_char(self, char: int | bytes) -> None:
self.console.push_char(char)
self.handle1(block=False)
def readline(self, startup_hook: Callback | None = None) -> str:
"""Read a line. The implementation of this method also shows
how to drive Reader if you want more control over the event
loop."""
self.prepare()
try:
if startup_hook is not None:
startup_hook()
self.refresh()
while not self.finished:
self.handle1()
return self.get_unicode()
finally:
self.restore()
def bind(self, spec: KeySpec, command: CommandName) -> None:
self.keymap = self.keymap + ((spec, command),)
self.input_trans = input.KeymapTranslator(
self.keymap, invalid_cls="invalid-key", character_cls="self-insert"
)
def get_unicode(self) -> str:
"""Return the current buffer as a unicode string."""
return "".join(self.buffer)
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